

$..4'.4r 


, 


MANUAL 


OF 


NORTH AMERICAN DIPTERA 


BY 


SAMUEL W. WILLISTON 


THIRD EDITION 


NEW HAVEN 
JAMES T . H A T H A W A V 

297 CROWN ST. NEAR YALE COLLEGE 
1908 


COPYRIGHT, 1908, 

BY 
SAMUEL W. 


103 


PREFACE. 

Twenty-four years ago the writer began the publica- 
tion, in the Bulletin of the Brooklyn Entomological 
Society, of a series of synoptic papers on the families and 
genera of North American Diptera. Previous to that 
time but seven of the sixty odd families had thus been 
rendered accessible to the American student in the works 
of Loew and Osten Sacken. In 1888 these synopses 
w^ere revised and published, with others, in a pamphlet 
of 88 pages entitled ' Synopsis of the Families and 
Genera of North American Diptera, exclusive of the 
Nematocera and Muscidae.' It contained tabular defini- 
tions of about three hundred and fifty genera, all at that 
time known from the United States in the families treated. 
In the succeeding eight years the writer's acquaintance, 
especially with the southern forms, had been so widened 
that he attempted a similar review of all the North and 
Middle American genera, aided by Professor Aldrich in 
the Dolichopodidae and Mr. Snow in the Ortalidse. Re- 
gretfully the very large and almost chaotic families 
Dexiidse and Tachinidae were not included. Eight hun- 
dred and twenty-six genera were defined in this 'second 
edition' more or less accurately, very nearly all of which, 
save those of the Dolichopodidse, had been studied by 
the writer in its preparation. The continued use of this 
work, both in America and abroad, has been very grati- 
fying to the author, a use that has made him the more 
desirous that a better and more complete edition should 
be prepared, one that would be of greater service to the 
amateur, whose interests have been paramount. For such 
an edition the present time seemed opportune, since the 
recently published catalogue of the Diptera of North 


4 NORTH AMERICAN DII'TKRA. 

America, by Professor Aldrich, a very meritorious work, 
has lessened materially the labor of its preparation, and 
must add to its usefulness. It was with some misgivings, 
however, that the author undertook the no inconsiderable 
task, since his studies for some years past have been 
almost wholly in a widely different field from that of 
entomology vertebrate paleontology, a subject which, 
indeed, has absorbed the larger share of his attention 
for the past thirty years. 

But, he would not have undertaken the task, save 
upon the kind assurance of assistance and contributions 
by several of the leading students of diptera in the United 
States. The chief progress during the last twelve years 
has been in comparatively few families, the most of which 
had been but indifferently well studied at the time of the 
publication of the second edition; a progress in large part 
due to the work of the present ^contributors. 

Professor C. F. Adams has kindly aided in a large 
part of the work, especially the Cyclorrhapha, though 
the writer assumes all responsibility for changes and ad- 
ditions not directly accredited to the several contributors. 
Professor Adams has also furnished the tables for the 
very difficult families Dexiidae and Tachinidae, omitted 
in the previous edition. As in the former edition, the 
characters and table of the Dolichopodidae are wholly 
the work of Professor Aldrich; he has also generously 
assisted in other ways, and it need not be said that, with- 
out the aid of his Catalogue, the labor of revision would 
have been greater, and the results less satisfactory. 
Mr. C. T. Brues, who has given so much critical attention 
to the singular family Phoridse, has furnished the char- 
acters and table of that family; one needs to compare his 
table with that of the former edition to see how much has 
been done in that group. Professor James Hine has re- 
vised the characters and table of the Tabanidse. Professor 


PREFACE. 5 

O. A. Johannsen has furnished a new table of the Chiro- 
nomidae. Professor V. L. Kellogg has done the same for 
the Blepharoceridse, and has revised the family charac- 
ters. Professor A. L. Melander has treated the Empididae 
anew; and Professor C. H. T. Townsend has generously 
criticised the figures of the Dexiidse and Tachinidae, and 
has furnished important notes on many of the genera. 
To all these gentlemen the author tenders his sincerest 
thanks, not only on his own part, but also on the part 
of those who will have occasion to use the work. 

At the outset it was not contemplated to give many 
illustrations, chiefly such as would be explanatory of 
the mere important characters. In the end more than 
six hundred genera have been defined more or less fully 
and decisively by nearly one thousand figures. Of these 
figures all these of the Dolichopodidae and the first plate 
of those of the Tachinidae were furnished by Professor 
Aldrich. Mr. Brues has furnished the figures of the Phori- 
dae, Professor Hine those of the Tabanidae, and Professor 
Melander most of those illustrating the Empididae. Pro- 
fessor Washburn kindly gave permission to use electro- 
types of twenty-three figures prepared for his or the late 
Professor Lugger's reports on Minnesota Diptera. To 
Professor Kellogg and Henry Holt & Co. the writer is 
indebted for eight electrotypes of figures in Professor 
Kellogg's American Insects; and to Professor J.B. Smith 
his thanks are due for six figures of the Culicidae, orig- 
inally prepared for his Report on the Mosquitoes of New 
Jersey. A few other figures have been copied from relia- 
ble sources, where specimens were net easily accessible, 

and are likewise credited in each case to its author. All 
the remainder, whether drawings or photographs, more 
than eight hundred in number, have been made by the 
writer from specimens a task which has involved many 
months of labor, but which could not, in most cases, have 
been safely entrusted to a professional draftsman. 


6 NORTH AMERICAN DIPTERA. 

To the authorities of the National Museum and Mr. D. 
W. Coquillett, the writer is indebted for the communica- 
tion of specimens of fourteen genera for purposes of illus- 
tration. Finally he has to express his hearty thanks to 
his friend and former colleague, Dr. F. H. Snow of the Uni- 
versity of Kansas, for the free permission to make use of 
whatever specimens were needed in the rich collections of 
that University collections which include nearly all the 
types of diptera from the United States described by 
Townsend, Snow, Adams and the writer. 

Since the preparation of the present edition was begun 
has occurred the death of one whose name will ever be 
honorably associated with American Dipterology, Dr. C. 
R. Osten Sacken. The author can not forbear placing 
on record here an earnest tribute of friendship and ad- 
miration for the man, and unqualified appreciation of 
his work as an entomologist. His constant encourage- 
ment and kindly criticism during a correspondence of 
more than twenty years have made this book, whatever 
be its merits, possible; and the author only hopes that it 
may be found not unworthy of association with his work. 
It is with pain, also, that the author here records the 
death, in early years, of his friend and student the late 
Mr. W. A. Snow, who assisted in the preparation of the 
Ortalidse of the former edition. 

About twelve hundred genera are defined in the pres- 
ent edition, with the exception of a few doubtful forms, 
all those known from North and Central America and 
the West Indies. That the definitions are wholly with- 
out error is inconceivable. Whatever revision the book 
may receive in the future must be left to others, and, 
in taking final leave of it after these twenty-four years, 
the writer will be pardoned in repeating the words of a 
master, one whose works have served as models for this, 
Rudolph Schiner: 

'Und so nebergebe ich derm cliese meine Arbeit der Oeffentlichkeit 
mil dem Wunsche, dass sie billigen Anfordeningen eiitsprechen inoege 
und niit dem Beifuegen, dass ich dem Urtheile vmparteiischen L/eser 
mit voller Beruhigung entgegensehe, da ich bewusst bin, bei L,oesung 
meiner Aufgabe mit allem Ernste und der groessten Gewissenhaftig- 
keit vogegangen zu sein.' 

SAMUEL W. WIIvUSTON. 

UNIVKRSITY OF CHICAGO, June, 1908. 


CONTENTS. 

INTRODUCTION .......... 9 

Structure and habits of flies ...... 16 

Morphology ........ 20 

Head .......... 20 

Mouth-parts . ..... 24 

Antennae ......... 27 

Thorax ......... 31 

L,egs .......... 34 

Abdomen ......... 36 

Wings ..... ... 27 

Vestiture ......... 43 

Chaetotaxy ........ 45 

Internal anatomy ....... 49 

Classification of diptera ....... 51 

Collection and preservation of flies .... 62 

GROUP CHARACTERS AND SYNOPTIC TABLE OF THE FAMILIES OF 

DIPTERA ........ 65 

FAMILY CHARACTERS AND SYNOPTIC TABLES OF GENERA 

I Tipulidae ... ... Si 

II Psychodidae ........ 92 

III Dixidae 94 

IV Culicidae ........ 96 

V Chironomidae . . . . . . . no 

VI Cecidomyidre . . . . . . 117 

VII Mvcetophilidae ....... 131 

VIII Bibionidae ........ 140 

IX Simuliidae .... , 144 

X Blepharoceridae ...... 148 

XI Orphnephilidae . .... 153 

XII Rhyphidae ........ 155 

XIII Leptidae ......... 157 

XIV Stratiomyidae ....... 164 

XV Acanthomeridas . . . . . . . 173 

XVI Tabanidae . . . . . . . . 176 

XVII Cyrtidse 182 

XVIII Nemestrinidae ...... 186 

XIX Apioceridas . . . . . . . . 188 


8 


NORTH AMKRICAN DIPTKRA. 


XX 
XXI 

XXII 

XXIII 

XXIV 

XXV 

XXVI 

XXVII 

XXVIII 

XXIX 

XXX 

XXXI 

XXXII 

XXXIII 

XXXIX 

XXXV 

XXXVI 

XXXVII 

XXXVIII 

XXXIX 

XL 

XLI 

XLII 

XLIII 

xuv 

XLV 

XLVI 

XLVII 

XLVIII 

XLIX 

L 

LI 

LII 

LIU 

LIV 

LV 

LVI 

LVII 

LVIII 

LIX 

LX 

LXI 


Mydaidae 

Asilidse 

Therevidae 

Scenopinidae . 

Bombyliidse 

Empididae 

Dolicbopodidae 

Phoridse . 

Loncbopteridae 

Platypezidae 

Pipunculidae . 

vSyrpbidae 

Conopidae 

Tanypezidae 

Micropezidas . 

Psilidae . 

Sepsidae . , 

Ortalididae 

Rhopalomeridye 

Trypetidae 

Saproniyzidae 

Agroniyzidae . 

Geomyzidae 

Drosophilidae 

Kphydridae 

Oscinidas 

Diopsidae 

Borboridae 

Pbycodroniidae 

Heteroneurida; 

Scioniyzidae 
Helomyzidae . 
Cordyluridae . 
Anthomyidse . 
Muscidae 
Qistridae 
Sarcopbagidae 
Dexiidte . 
Tacbinidae 
Hippoboscidae 
Streblidte 
Nycleribiidae 


190 
192 
205 
208 

210 

218 

228 

336 

240 
241 

244 

246 

261 

264 
264 

267 

269 

271 
280 

282 

288 

291 

297 
299 

303 
310 

314 
315 
317 

318 

321 

324 
327 
331 

337 
344 


352 


APPENDIX . 


384 
386 

387 


INDEX 


NOETH AMERICAN DIPTERA. 


INTRODUCTION. 

The order of two-winged insects known as flies or Dip- 
tera includes more than forty thousand known species 
from different regions of the world. Since many of the 
species are small, or even minute, and inconspicuous, 
and since the order as a whole has not received the at- 
tention from collectors and students of entomology that 
other and more attractive groups have, it is very certain 
that many more await discovery. A very reasonable es- 
timate would place the entire number of species of flies 
at present in existence at more than eighty thousand. 
From North America the recent catalogue of Aldrich 
gives a list of about eight thousand species, distributed 
in more than a thousand genera. The subject is a wide 
one and replete with interest. 

To the student beginning the study of this interesting 
order of insects a few words of advice or caution may not 
be superfluous. The present work can make no preten- 
sions to completeness in the characterization of genera, 
at least in the majority of cases; that would require 
a work many times larger than is the present one, and is 
practically impossible at the present time. One must 
not, therefore, depend entirely upon tables and figures 
in the absence of other information and other assistance, 
especially \vhen he knows but few forms. If he does not 
immediately succeed in securely locating his specimens 


I0 NORTH AMERICAN DIPTKRA. 

he should not too hastily conclude that they are 'new'. 
Until he has acquired a considerable acquaintance with 
different families, the work of classification may at times 
be tedious, but by perseverance he can not fail to over- 
come \vhatever obstacles families and genera may pre- 
sent. He will be very much aided at the beginning by 
having a tolerably large collection at his command with 
which to make comparisons. Difficulties to the inexpe- 
rienced will often disappear with positive evidence before 
him, when negative characters would be doubtful. With 
each genus in a family positively determined, the diffi- 
culties and uncertainties of others will gradually disap- 
pear. Better still if he has numerous species reliably 
named with \vhich to begin his studies. The present 
writer in his entomological career had few if any species 
or genera determined for him by others, and he well ap- 
preciates how wasteful of energies was such a method, 
at the time unavoidable. For full generic descriptions 
of many, perhaps the larger part, of the North American 
genera, the student will find a most valuable aid in 
Schiner's Fauna Austriaca, a work of which too much can 
not be said in praise. The descriptions are remarkable 
for their fullness, accuracy and simplicity, and, although 
the work is forty years old, it has lost but little of its value. 
To determine his species the student will need access 
to a large number of books and papers, lists of which to 
the present time will be found in Aldrich's admirable 
and indispensable Catalogue of North American Diptera, 
published by the Smithsonian Institution. One must 
not, however, let the formidable lists frighten him. He 
will not need them all to begin with, nor even the larger 
part of them, and the earnest student can always be as- 
sured of the sympathy and assistance of his fellow work- 
ers. His earlier determinations, and those of the student 
who is concerned chiefly in obtaining a broad general 


INTRODUCTION. 1 1 

knowledge of the taxonomy of the diptera, may be con- 
fined, for the most part, to those groups which have been 
monographed, with full descriptions of genera and spe- 
cies, and, if possible with numerous illustrations. Refer- 
ences to the more important papers of each family will 
be found in Aldrich's catalogue. 

Long before the student has reached the dignity of 
'independent research', he will have learned who the 
masters of dipterology are ; who have shown the greatest 
acumen in the discernment and use of classificatory char- 
acters. It will not be invidious to distinguish above all 
others Schiner, Loew and Osten Sacken as writers who 
can not be too faithfully studied, too closely followed. 
Not that they are infallible; none are. Indeed an error 
of a master is often more instructive than the masterpiece 
of a dullard. One must learn the values of characters in 
classification before he can be successful in instructing 
others, or in making his discoveries known. And this 
knowledge can only be acquired by long and faithful 
study of living things and due- reflection thereon. The 
narrow systematic specialist is looked upon somewhat 
askance by modern biologists, and rightfully too, but I 
have no hesitation in saying, and it is the experience of 
many years of study in different branches of natural his- 
tory, that the right kind of systematic work calls for the 
highest scientific powers of the student. I am aware that 
some narrow specialists in other departments of science 
will take exception to this statement, but I believe it and 
say it for the encouragement of those who may be dis- 
suaded from the earnest study of such creatures by the 
flippant remark of the shallow minded. But a mere col- 
lector of specimens, one who finds enjoyment in getting 
the largest number and arranging them in serial form in 
his cabinet is not necessarily a scientific student, though 
he may have a very pleasant and useful pastime; his la- 


12 NORTH AMKRICAX DIITKKA. 

bors are scarcely more important than those of the micro- 
tomist who cuts up frogs' eggs and makes pictures of 
them. There are no principles too deep, no speculations 
too lofty to find application in such creatures as flies, the 
too often proletarians of the professional entomologist 
even. 

Most emphatically I would impress upon all students 
of dipterology who undertake the subject seriously, that 
the greatest need of modern entomology is monographic 
work. Nearly every family awaits the conscientious 
monographer, and such work is that which lasts longest 
and acquires most renown. The problems of distribution, 
of relationship, of origin, of the effects of environments, 
or the meaning and value of characters, can be satisfacto- 
rily solved b}^ critical monographic studies only. The 
description of 'new species' as mere membra disjecta of 
faunas, is scarcely worth the energies of the earnest and 
careful student, certainly not as a life vocation, and none 
else has any business to write at all. It too easily degen- 
erates into a mere roll-calling, a catalogue of the permu- 
tations of a few characters, increasing the difficulties for 
real students who come afterward. The name that an 
insect is known by is of trivial importance, and no one 
cares who described it, unless he did it poorly. It will 
be a fortunate thing when the search for 'new species' 
and the interminably haphazard making of 'new genera' 
is done. 

Even a cursory glance at some of the tables further on 
will convince the intelligent student that the real mean- 
ing of many of the classificatory characters is yet imper- 
fectly comprehended. But little attention has been paid 
to homoplasy or 'convergent evolution', and as all true 
classification must depend upon the proper use of genetic 
characters, it is apparent that future revisions may ma- 
terially modify our present conceptions of relationships 


INTRODUCTION. !- 

V ' 

in many cases. I can offer no better example of this dis- 
regard for phylogenetic and convergent evolution than is 
shown in the proposed scheme of classification of the 
Cecidomyidae on later pages. The structure and use of 
the organs of orientation, the antennae and palpi especial- 
ly, the further comparative study of the ocelli and eyes, 
the reasons for the evolution of the wing venation in ap- 
parently different systems, the causes of the variations in 
the patterns of coloration, the meaning more fully of the 
different kinds of vestiture, etc., etc., all need much more 
attention than has been given them by the systematist, 
and it is he who is best qualified to solve such problems. 
One of the first questions that a novice in classification 
asks is: What is a species, genus, family? The taxono- 
mist's answer to the first of these queries is easy: A spe- 
cies is a form of life with all its fertile variants. A mas- 
tiff and a grayhound are not distinct species of dogs, 
because there exist all possible variations between the 
two types, though both have bred true to themselves for 
more than three thousand years. But a dog and a fox 
are distinct species because there exist no varieties con- 
necting the two. If no two specimens in a given form of 
fly have precisely the same relative lengths of the anten- 
nal joints, then the relative lengths of these organs is not 
a specific character in that form. If, however, all the 
specimens occurring in Massachusetts have a definite 
relative length for each joint while these in Kansas have 
another, the first impression is that they belong to dis- 
tinct species. If further discovery proves that, in cross- 
ing the country between Massachusetts and Kansas, the 
lengths gradually vary from one to the other, then we 
must consider the eastern and western specimens as mere- 
ly racial varieties of a single species. The systematist is 
never troubled as to what a species is, if he has all the 
material he wants. 


I4 NORTH AMERICAN DIPTERA. 

The answer to the second query, What is a genus? is, 
however, a very different matter. Ordinarily we might 
apply the same criterion, that groups of species gradu- 
ally blending together should not be separated into two 
or more genera. But this will not suffice, since, because 
of the actual presence of the connecting links, the ex- 
tremes may vary enormously, far more than in many cases 
where the connecting links have disappeared, leaving 
the extremes isolated into easily distinguishable genera. 
Both convenience and the demands of relationships re- 
quire here that such groups be broken up, though it may 
and often does entail the result that such genera may be 
ultimately distinguishable in their most allied species by 
only trivial characters. But the temptation offered here, 
especially to the narrow, perspectiveless specialist, is to 
use those same boundary characters, or their equivalents, 
as generic characters through the whole family, and the 
result is an almost innumerable number of proposed di- 
visions. As nearly every species of flies has some plastic 
or structural distinguishing character, it is very evident 
that we might ultimately reach the absurd result of mak- 
ing species and genera coterminous. Between this ex- 
treme and the other, the grouping of large numbers of 
species into genera, all of which can be distinguished by 
decisive, if not important, structural characteristics, there 
must be a happy mean. This mean, however, must de- 
pend more or less upon the opinions of those best quali- 
fied to interpret them. In other words I am tempted to 
define a genus as being merely the personal opinion of its 
proposer. By an excessive 'splitting' of genera, broader 
relationships are lost sight of, and the tendency is inevit- 
able to restore those evidences by the invention of new 
group terms to express them. Perhaps no better exam- 
ples of these tendencies are observable than in the more 
recently proposed classification of the mosquitoes. For 


INTRODUCTION. I5 

man}' decades systeniatists were satisfied to distribute the 
known mosquitoes in a relatively small number of genera, 
genera which could be defined by characters equivalent to 
those used in the allied families of diptera. With the great 
impetus given to the study of these insects by the discov- 
ery of their agency in the spread of disease, the genera 
have been broken up into man}' new divisions, until sev- 
enty or eighty are now recognized by some students of 
the family. In the dearth of striking characters, those 
of extreme minuteness have been resorted to, such as the 
relative lengths and widths of the scales and their distri- 
bution on the body; and even colorational characters 
have been called in aid. The obliteration of relationships 
thus brought about has rendered the erection of numer- 
ous subfamilies necessary, and it is even seriously pro- 
posed to elevate the previously accepted subfamilies to 
family rank, and the family Culicidse to a superfamily! 
And I doubt not that some zealous confrere may yet se- 
riously propose to consider the eld family Culicidae as a 
suborder! Possibly also, it may be necessary some time 
in the future to have a quantitative chemical analysis of 
a mosquito before deciding to which genus it may belong. 
Now it is very apparent that the importance of the mos- 
quitoes in man's economy can have no value in classifica- 
tion; that, if the happiness and welfare of every living 
being were dependent upon the mosquitoes it could not 
affect the classification of the family one whit ; but some- 
thing of the sort seems to have resulted. 

I will admit that excessive 'splitting' of genera often 
brings to light and tests many differential characters 
which otherwise might long remain obscure. Neverthe- 
less, convenience is an important end of classification, as 
well as the expression of relationships. In days gone by 
the profuse maker of genera was ridiculed and the results 
of his labors were largely ignored ; but I fear even Des- 


!6 NORTH AMERICAN DIPTERA. 

voidy's shade would turn pale with envy in the contem- 
plation of some of the proposed genera of the modern 
culicidologists. 

STRUCTURE OF FLIES. 

The word diptera, by which the two-winged flies are 
known, signifies two wings, the chief characteristic of 
the adult insects. All diptera, if they have any wings, 
have but a single pair. The hind pair of other insects is 
really represented by a small organ on either side, back 
of the true wings, consisting of a short, slender stem, 
terminating in a knob. The precise function of these 
'halteres' or 'balancers', as they are called, if they have 
any, is not known ; that they have a secondarily acquired 
use is probable, since they are always in vibration 
during flight; an orienting or balancing function has 
been ascribed to them. The halteres are very character- 
istic of the order, always present in the winged forms, 
and usually present even in those in which the true wings 
are aborted or functionless, though rarely they are en- 
tirely absent. Not all flies are winged, as has been al- 
ready intimated ; rarely, among both the more general- 
ized and the more specialized groups they are imperfectly 
developed or wholly wanting. Their absence is not of 
very great classificatory importance, never more than 
generic, and sometimes doubtfully that. Sometimes the 
male has wings and the female is wingless ; but the num- 
ber of wingless forms of any kind is very small. 

In size as well as in shape, flies vary not a little. As 
compared with the lepidoptera, orthoptera, neuroptera, 
and even the hemiptera, flies are relatively small insects. 
The largest specimen of a fly of which I have knowledge 
is that figured herewith natural size, pertaining to an 
indeterminable species of Mvdas from South America. 
The length of this specimen from the tip of the antennae 


Fii(. i. Mydas. species indat. Life size. (Brazil.) 


Fig. 2. Acanthomera, species indet. Life size. (Venezuela.) 


INTRODUCTION. jy 

to the extremity of the abdomen, is sixty-seven millime- 
ters, or, omitting the antennae, fifty-two millimeters; the 
expanse of wings one hundred and seventeen millimeters, 
or a little more than four and one-half inches. The 
smallest dipteron that I have ever observed in the 
examination of many thousand specimens and five 
or six thousand species, is that of a cecidomyid measur- 
ing a trifle less than one half millimeter, also omitting 
the antennae. In other words, the My das is more than 
one million times the size of the cecidomyid. Possibly 
there are still greater discrepancies between the largest 
and smallest specimens of the order, but in all prob- 
ability not much. The largest insect known is one 
allied to the dragon flies, an extinct Devonian species 
which measured about fifteen inches in length. As- 
suming that the bodily proportions of the largest and 
smallest hexapods are not unlike, the extremes of size or 
weight are more than four hundred millions apart. In 
no single family of diptera are the differences in size 
anywhere nearly so great as those between the mydaid 
and cecidomyid. Seldom do the differences in linear meas- 
urements in any one family exceed ten fold. Among 
other families of diptera the tipulids, asilids, and especial- 
ly the pantophthalmids, often furnish examples of large 
size, while the tabanids, syrphids and cyrtids have not a 
few forms of considerable size. The largest of all the 
Cyclorrhapha will be found among the Calypterae, while 
the Acalypterae are rarely much above the average in 
size, and many are small, or very small. 

Giantism in any group of animal life is a specialization, 
and is, in general, an indication of approaching decadence; 
enduringly small races are never the descendants of 
giants, for decrease in size means lessened vitality an-d 
incipient extinction. No strong or dominant group of 
flies, like the Tachinidae, Dolichopodidae, Syrphidae, cr 
3 


iS 


NORTH AMERICAN DIPTERA. 


Bombyliidae, has ever had in the past a larger average 
bodily size than is found among their living representa- 
tives. On the other hand, those families composed to- 
day chiefly of large forms are ones already past their 
prime. These conclusions seem established for the larger 
forms of life, and I believe that they are in the main also 
applicable to insects. 

Many curious resemblances of external form are ob- 
servable among diptera belonging to widely different fami- 
lies and of remote relationships. Some of these, perhaps 
many, have a protective value, in flies of like habits; or 
they may have been the results of like environmental 
conditions. 


Ceria. 


Cerioniydas. 


Conops. 


Fig. 3. Examples of mimetic resemblances in flies. Ceria (Syrphidae); 
Ccriotnydas (Mydaidae); Conops (Conopidae). Slightly reduced. 

In figure 3 are given photographs of three wasp-like 
flies of very different families and of considerable size, 
all of them associated in the same fauna, and curiously 


HABITS. ig 

resembling each other; several others equally striking 
might have been associated in the same group. 

The habits of flies are very diverse. Many are prop- 
erly spoken of as flower flies that is, insects whose sub- 
sistence, for the most part or entirely, is obtained from 
the honey or pollen of flowers, and the sweetened sap 
of plants. Among these are many which are swift in 
flight, spending most of their time during sunny hours 
upon the wing or resting lightly upon leaves and flowers ; 
they all love the warmest sunshine. Some mature flies 
feed upon ordure or decaying material of whatever nature 
it may be. Many others, including whole families like 
the Asilidse, Dolichopodidae and Empididae, find their 
subsistence in the juices of other insects, and are often 
predaceous in the highest degree. Others, like the female 
mosquitoes, blackflies and horseflies, are bloodsucking 
in habit, though not exclusively so, and are often very 
annoying to man and other warm-blooded animals. The 
whole group of Pupipara, with the exception of the Brau- 
lidse, are of this kind, living parasitically upon and suck- 
ing the blood from mammals and birds. In the previous 
edition of this work I expressed the opinion that, upon 
the whole, the order of diptera is beneficial to man's econ- 
omy, since so many of its members, whether in the larval 
or adult conditions, are either useful scavengers, destroy- 
ing that which otherwise might cause distress, or prey 
upon other and injurious insects. Since the publication 
of that edition, however, the many marvelous and import- 
ant discoveries of the parasitic habits of certain ver}^ 
small protozoans which find their intermediary hosts in 
certain flies, by whose instrumentality they are trans- 
mitted to man and some of his most valued domestic ani- 
mals, will require the complete reversal of that opinion. 
Yellow fever, malaria, and filariasis, transmitted in the 
saliva of mosquitoes, and the fatal 'sleeping sickness' 


20 NORTH AMERICAN DIPTERA. 

(trypanosomiasis), likewise resulting from the predatory 
bites of the tsetze fly, are among the most virulent or 
widespread diseases of mankind. Perhaps we may justly 
say that the order, so far as man is concerned, is the 
most pestilential of all animal life. 

In the larval condition the habits of flies are even more 
diverse than are those of the adult insects. Brief refer- 
ences to the larval habits will be found in the discussion 
of the families. Suffice it here to say that the larvae or 
'maggots' of diptera are, for the most part, vegetable 
feeders, but not a few feed upon living or decaying ani- 
mal matter; and many are parasitic within the bodies of 
other insects, whether larvae or adults, snails, reptiles, 
birds and mammals, and possibly also amphibians and 
fishes. 

MORPHOLOGY OF DIPTERA. 

In the following pages I endeavor to give such defini- 
tions and descriptions of the mature insect as will enable 
the student to understand and appreciate, not only the 
present work, but all other systematic works upon dip- 
tera. I have not thought it desirable to consider at length 
many interesting subjects connected with them, such as 
their internal anatomy, embryology, larval habits, etc., 
as being rather apart from the chief object of the work 
an introduction or aid to the study of systematic dipter- 

ology. 

HEAD. 

The head in diptera is very variable in shape, reaching 
its most remarkable development in the Diopsidse and 
Nycteribiidse. It is frequently more or less spherical, 
but usually the posterior surface or occiput is flattened . 
or concave, giving a more hemispherical appearance. 
The face is rarely produced into an elongated rostrum 
or snout, and the front part may be produced into a con- 
ical prominence. Its relative size is also variable, some- 


HEAD. 2 1 

times distinctly wider than the thorax, at other times 
small. In the Nycteribiidae it may be folded back into a 
groove on the dorsum of the thorax, but with these ex- 
ceptions, it is always attached to the thorax by a freely 
movable neck. The taxonomic characters furnished by 
the head are second only in importance to those of the 
wings. 

Eyes. The large compound eyes are present in all dip- 
tera, save seme Pupipara. In the majority of males, 
especially of the Orthorrhapha, they are contiguous on 
the upper side of the head, between the insertion of the 
antennae and the hind margin, for a longer or shorter 
distance; insects having such contiguous eyes are called 
holoptic (Osten Sacken). In many males, however (all 
the Acalypterae and several families of the Orthorrhapha, 
as well as numerous genera of other families), and in 
all females, with but few exceptions (certain Cyrtidae, 
Orphephilidae, Blepharoceridae, Bombylidae, Platype- 
zidae, etc.), the eyes are separated more or less broadly 
by the front: such insects are called dichoptic ( Williston ) . 
Rarely the eyes may be contiguous below the antennae, 
or both above and below, as in certain cyrtids, etc. In 
not a few flies, especially those of the aerial, bristleless 
kinds, the upper facets of the eyes are larger and more 
conspicuous than the lower ones, sometimes separated by 
a distinct line, or even entirely divided. This peculiar- 
ity is rarely seen in the female or even in the dichoptic 
male, though the dichoptic Asilidae may have the anterior 
facets somewhat enlarged in both sexes. Those flies hav- 
ing such enlarged facets usually have the eyes in life 
brilliantly and beautifully colored with green and purple 
markings markings often characteristic of the various 
species, and the general pattern even of the genera. 
Unfortunately such markings are obliterated by dessica- 


22 NORTH AMERICAN DIPTKRA. 

tion, though the}'' may be somewhat revived temporarily 
by the aid of moisture. 

Most flies have the eyes bare, or pubescent only when 
seen under high magnification. Not rarely, however, 
the \vhole or part of the eyes is covered with erect short 
pile, a character which usually, perhaps always, finds its 
greatest development in the male sex. The pubescence 
or pilosity may be sparse or dense, short or long, and is 
usually, though not always, of generic importance. 

Ocelli. On the upper part of the front in the middle, 
between or a little back of the compound eyes, there are 
three simple, small eye lenses, present in most diptera, 
and called ocelli. The)' are by no means constant among 
all the genera of some families, or even among all the 
species of some genera. They are usually situated in 
the form of a triangle with the apex in front ; sometimes 
they are located in a nearly straight line transversely; 
or, the middle one may be rarely absent, and the other 
two situated, one on each side, near the compound eyes. 

Front. The space between the eyes in all dichoptic flies, 
limited by the upper margin of the head and the line 
drawn through the root of the antennae, is called the front. 
It may be wide or narrow, excavated or convex, etc. 

Vertex. The uppermost part of the front, near the mar- 
gin of the occiput, which is here called the vertical margin. 

Vertical triangle. The triangle at the upper part of the 
head, "between the eyes in holoptic flies. It bears the 
ocelli, which may be situated on a triangle indicated by 
grooves or depressions or colorations, called the ocellar 
triangle. 

Frontal triangle. In holoptic flies, the triangle between 
the eyes and the root of the antennae, the apex of which 
is above. Sometimes the term is applied to a triangle 
indicated by color or depression in the dichoptic front. 

Ptilinum. In the Cyclorrhapha an inflatable organ ca- 


HEAD. 


pable of being thrust out through the frontal suture just 
above the root of the antennae, and which is used by the 
imago in springing off the cap to the puparium when 
about to extricate itself. 

Frontal lunule. An "oval or crescentic space just above 
the root of the antennae in cyclorrhaphous flies, bounded 
by the frontal suture. 

Epistoma or Peristoma. The oral margin and an indefi- 
nite space immediately contiguous thereto; not often 
now used. 

Antennal fovea or groove. A groove or grooves in the 
middle of the face, as though for the lodgment of the an- 
tennae, bounded on the sides by the facial ridges. 

Cheeks or "jowls'. The space back of the face and below 
the eyes. 

Orbits. The space immediately contiguous to the eyes, 
sometimes indicated by structural characters, at other 
times indefinite. It is called facial, frontal, etc., from 
the position. 

Clypeus. A part of the mouth structure, often visible 
below the margin of the mouth in front as a more or less 
visor-shaped piece. 


Fig. 4. Mouthparts of female Tabanus. After Washburn. mp, maxil- 
lary palpus; ?//, mandible; m.\\ maxilla; Ib, labium. 


NORTH AMERICAN DIPTERA. 

MOUTH-PARTS. 

The mouth-parts of diptera are wholly suctorial. The}' 
differ not a little in different flies, as might be supposed 
from their diverse habits. In some they are adapted for 
piercing animal or vegetable substances, and are, in con- 
sequence, firmer and more slender; in others, and by far 
the greater number, they are short and soft, with a thick- 
ened extremity used for the attrition of small particles of 
solid substances. Grains of pollen have been observed in 
the digestive organs of the Syrphidae and other flower 
flies, but, as a rule, fluids only serve as food. Many have 
the proboscis wholly retractile into the oral cavity, and 
furnished with one or even two hinges, by which when at 
rest it may be folded up. In others the proboscis is not 
retractile, and projects either in front, or downward or 
backward, beneath the body. While it is usually short, 
it may be much longer than the body. Finally, a few 
species have the mouth-parts vestigial and take no nour- 
ishment in the adult state. 

The more commonly accepted homologies of the mouth- 
parts are as follows: labium, maxillae, maxillary palpi, 
mandibles, hypopharynx, and labrum or labrum-epiphar- 
ynx. The labial palpi are thought to be wholly wanting, 1 * 
or represented by the labella. The labium is always 
present, more or less fleshy and provided with muscles. 
It is grooved or channeled on the upper side to receive 
the other parts, with the exception of the maxillary palpi, 
which are free. This sheath is often nearly complete, 
the thin margins touching each other above. At its tip 
are the pair of joints of variable size called the 'lips' 
or labella. The maxilla and mandibles are sometimes 

*This has very recently been contested by Wesche, who asserts that 
either the labial or maxillary palpi may be present and functional; but 
no cases are known of both pairs being functionally present. I am 
inclined to be skeptical. 


MOUTH-PARTS. 25 

absent, the mandibles most frequently; when present 
they are always slender and firm. The hypopharynx is 
unpaired and slender, grooved on the upper side and 
sometimes converted into a nearly complete tube. The 
labrum, also unpaired, is usually elongate and grooved 
on the under side, forming by apposition with the hypo- 
pharynx a complete tube. The mandibles are frequently 
absent ; in fact I do not know of their occurrence in any 
flies with a simple third antemial joint, and they may be 
absent in the male when present in the female, as in the 
Tabanidae. They are always piercing organs, thin, firm, 
chitinous and usually slender. The two maxillae, like- 
wise piercing organs, find their highest development in 
such predaceous flies as the Asilidse. Like the mandi- 
bles they are chitinous and slender. In some they are 
more or less flattened, and may have curiously shaped 
projections at the tip; usually they are bristle-like. 
They lie with the maxillae within the sheath of the labi- 
um, at either side of the labrum and hypopharyiix. In 
some cases the labrum is short, and serves only as a cov- 
er for the proximal part of the hypopharynx, but usually 
it is as long as or longer than the hypopharynx and has 
a simple groove on the under side. The hypopharynx 
is always present in flies in which the mouth-parts are 
functional. It is, more often, a slender, firm organ, 
grooved upon the upper side, which by apposition with 
the labrum forms a distinct tube. In some, however, 
it may form an almost complete tube in itself. 

Leaving out of account the degraded, but highly spe- 
cialized Pupipara, the labium is always a sheath for all 
the other organs except the palpi, but is separable at the 
will of the insect. It is not used in piercing; it is either 
bent backward in the middle, as in the mosquito, or the 
piercing parts are thrust out at the extremity as in most 
of the predaceous flies. To facilitate this protrusion of 
4 


2 6 NORTH AMERICAN DIPTERA. 

the piercing parts, the proximal portion is more or less 
membranous and retractile; or, the inner organs may be 
capable of elongation, being coiled up in some cases, as 
in Pangonia, within the pharyngeal cavity. The pair of 
organs at the extremity, the lips or labella, are very va- 
riable in shape, position and function. In the mosquito, 
for instance, they serve merely as a pair of fingers to 
guide the piercing parts. In many of the flower-flies with 
long proboscis, they are small, oval, divaricable organs, 
that seem to be chiefly sense organs, as they are usually 
provided with hairs inserted in small, semi-translucent 
spots on the outer sides and margins. In the greater 
number of flies, however, the labella are of considerable 
size, and are provided with radiating ridges on the inner, 
opposable sides. These pseudotracheae, as they are call- 
ed, serve as means of attrition, by which the insects rub 
off particles of food from firm substances. Sometimes 
the labella are long and slender and folded back under 
the labium when at rest. In the Asilidse and some others, 
they are rigid and horny. 

Perhaps the most important of all the mouth-parts, 
from the systematic stand point, are the maxillary palpi. 
They are inserted at the inferior basal part of the pro- 
boscis, on a thin plate which bears the maxillae, and 
are always extricated. Their study has been much neg- 
lected, and doubtless thorough comparative researches 
will reveal not a few characters of value in classification. 
They are variously described as being composed of from 
one to five joints.* There are never more than four articu- 
lated joints, the basal joint being merely a process of the 
plate bearing the maxillae. The tendency in diptera is 
toward their entire loss, and in the more highly special- 
ized families there is never more than one joint. They 

*Theobald says some Ciiliculae have six joints, but his statement 
needs confirmation. 


ANTENNA. 27 

may be reduced to the merest vestiges even in flies which 
are more or less predaceous in habit and which have the 
mouth-parts, with the exception of the mandibles, other- 
wise well developed ; they may indeed be absent or pres- 
ent in otherwise closely related genera of flies. They are 
seldom much elongated, save among some of the Nemo- 
cera. 

ANTENNAE. 


Fig. 5- Antennae, i, Tipulidse i/Wr;;/tVtf, female); 2, Tipulidae 
( Rlnp iiiia, male); 3, Culicicke (^Icdes, male); 4, Tabanidse (Stidaso- 
in,i)\ 5, Kmpididee (/)ru/>t'tis\\ 6, Syrphidae {Volucella)\ 7, Tachiiiidre 
( (,'onia I. 

No other organs furnish so many or so important char- 
acters in the classification of Diptera as do the antennae, 
or feelers as they are sometimes called. The number, 
shape and arrangement of the joints or segments offer 
not only the best of specific characters in nearly all cases, 
but also not rarely generic, family and even subordinal 
characters. Only in very exceptional instances is the 
number less than three, and it is probable that, even 


2 8 NORTH AMERICAN DIPTKRA. 

ill those, there is only a partial atrophy of the basal joint. 
Some Cecidomyidae and Leptidae ( ' Rhachicerus) have as 
man) 7 as twenty-eight distinct joints, and it has been said 
there are as many as thirty-nine in some Cecidomyidae 
(Cerodozia? ), but I can find no certain evidence support- 
ing such a statement. Through all the Cyclorrhapha 
the number three, or very rarely less, is constant. In 
the nematocerous Orthorrhapha the number is usually 
from eight to sixteen, though in rare cases there may be 
as few as six. In such antennae the first two joints are 
called the scape, and they are always more or less differ- 
entiated from the remaining segments which compose the 
flagellum. When the antennae are long, or more or less 
filiform, the joints of the flagellum often bear whorls or 
verticils of hairs, especially in the males, and these hairs 
are sometimes of very peculiar structure, sometimes loop- 
ed ; in such antennae, also, the joints may have a Icng 
and abundant plumosity. 

The scape in all flies usually bears bristles or bristle- 
like hairs; the joints of the flagellum seldom. Upon the 
structure of the antennae alone, however, it is difficult, if 
not impossible, to distinguish any of the larger groups of 
diptera, since those with long and multiarticulate antennae 
merge very gradually into forms with shorter antennae 
and fewer joints. Or, the separate joints of the flagel- 
lum may be fused so closely as to be distinguishable 
with difficulty, so that the third joint, or the basal part 
of the flagellum, may appear to be of a simple, uncliffer- 
entiated structure, though upon closer examination found 
to be composed of distinct segments or annuli ; in such 
cases the term complex is applied to the apparent joint. 
This peculiar structure will be readily understood by the 
examination of the antennae of a common horsefly (fig. 
5, 4), where the enlarged third joint is observed to be 
composed of a large basal piece and a terminal portion 


ANTENNA. 


29 


of four closely united segments. By the comparison of a 
horsefly's antennae with that of a Bibio and that of a mos- 
quito it will be easily understood that the complex third 
joint is merely the closer fusion of the real joints of the 
flagellum, though I know of no instance of a complex 
joint having more than eight segments. Nor is the horse- 
fly's so-called third antennal joint homologous with that 
of the housefly, but rather with the joint and the 'arista' 
combined. Either the complex or the simple third joint 
may terminate in a more or less slender, and more or less 
freely differentiated portion called the style, or in a bris- 
tle-like, elongated portion, called an arista. It is very 
evident, however, that the style or arista represents 
merely attenuated distal joints of the flagellum, since a 
close examination of them will invariably, or almost in- 
variably, disclose from two to five segments (fig. 5, 7), 
though some may be very small or almost completely 
atrophied. The arista therefore as might be supposed, 
is not sharply distinguishable from a slender style ; in- 
deed the arista always, or almost always, has its basal 
portion thickened more or less, in some cases so much so 
as to form a real though short style provided with a long 
bristly extremity; and the style is often provided with a 
short bristly end. An examination of the antennae of the 
Leptidae and Stratiomyidae, figured further on, will make 
these statements clear. The arista or style is of course 
not at all apparent in the Nemocera, since the antennal 
structure is here generalized, and it maybe entirely want- 
ing among the Brachycera, either because the distal 
flagellar joints have not become at all differentiated, as 
may be observed in Xylophagus of the L,eptidae, or because 
there has been an actual atrophy of the distal part of the 
antennae; but the cases are rare where some of the flag- 
ellar joints beyond the basal one are not observable in 
flies, albeit very rudimentary. Whenever the style or 


NORTH AMKRICAN DIPTKRA. 


arista is composed of numerous segments, the basal piece 
of the complex third joint has necessarily fewer segments, 
since both together never have more than eight. The 
style, as the term is usually applied, is always terminal; 
while the arista may be either terminal or dorsal, usually 
the latter, and it may even be inserted close to the base 
of the third joint. It is also apparent here, and this is 
the rule among the Cyclorrhapha, that the basal position 
is in reality due to the greater development of the under 
side of the joint, by which the width has greatly exceeded 
the length. The style is only rarely present in the Cy- 
clorrhapha ( Ceria, Conops} , and in but few known instances 
is the arista aborted in this suborder. 


Fij<. 6. Talarocera nigripennis, head of male from in front, much 

enlarged. 


The first two antennal joints, that is the scape, are, as 
has been said, usually provided with hairs or bristles, 


THORAX. 


but they rarely take on an extraordinary development. 
One or the other or both ma}' be greatly elongated (see 
fig. 19, Bombyliidae), or one or the other may be greatly 
swollen (see Therevidse). The third joint, however, 
has in some cases assumed most marvelous shapes, as 
among the Stratiomyiclse (Neochauna), or Tachinidae 
( Talarocera, figs. 6, 7, Schizotachina, Dichocera, etc.) 


Fig. 7. Talarocera nigripauiis, male and female antennae, from the 

side, much enlarged. 

Often the arista has short hairs fringing the upper 
and lower sides, in which cases it is called pubescent 
(fig. 5, 5); when the hairs are longer and more feather- 
like (fig. 5, 6), the arista is said to be plumose; or, if the 
hairs are fewer and stronger and confined to one side, 
pectinated. The pubescence or plumosity is almost always 
more marked on the upper side of the arista; the pecti- 
nation is very rarely on the under side (Ommatius^ Asi- 

lidse). 

THORAX. 

The thorax is composed, as in other insects, of three 
parts, the //^-thorax, the meso-ihora.^ and the meta- 
thorax, but the first and the last are so aborted as to pre- 
sent but few anatomical characters. The prothorax is 
perhaps most readily distinguishable in the nematocer- 
ous flies, forming a rounded collar back of the neck. The 


NORTH AMERICAN DIPTERA. 


metathorax is not seen at all from above; the scutellum, 
cut off by an impressed line, usually a semi-oval body, 
really belongs to the mesothorax, the dor sum of which 
is often called the mesonotum. 

Transverse suture, an impressed line usually running 
straight across the mesonotum and terminating a little in 
front of the root of the wings. It is more or less incom- 
plete in the middle. 

Humerus or humeral callus, each of the anterior superior 
angles of the mesothorax, usually a more or less rounded 
callus. 

Post-alar callus, a more or less distinct, rounded swell- 
ing, situated between the root of the wing and the scu- 
tellum. 

Pre-alar callus, a similar, but usually less prominent, 
projection situated before the root of the wings on the 
sides of the mesonotum, just back of the outer ends of 
the transverse suture. 

Scutellar bridge, a small ridge on either side of the scu- 
tellum, connecting it with the mesonotum. 

Presutural depression, a depression, usually triangular 
in shape, at the outer ends of the transverse suture, near 
the dorsopleural suture. 

Supra-alar groove, a groove on the mesothorax imme- 
diately above the root of the wings, along the inner mar- 
gin of which there are, usually, characteristic bristles. 

Fig. 8. Pleural divisions of 
Syrphus. 

Pro, propleura. 
Afeso, mesopleura. 
Sterno, sternopleura. 
Ptero, pteropleura. 
Hypo, hypopleura. 
Mela, rnetapleura. 


THORAX. 


33 


Notopleiiral or dorsopleural suture, the suture running 
from the humerus to the root of the wings, separating 
the mesonotum from the pleura. 

Stcrnopleural suture, the suture below the dorsopleural 
suture, nearly parallel with it and separating the meso- 
pleura from the sternopleura. 

Mesopleural suture, the suture running from the root of 
the wings downward and separating the mesopleura from 
the pteropleura. 

Mesopleura, the space situated in front of the root of the 
\vings, between the dorsopleural and sternopleural su- 
tures. 

Pteropleura, situated below the root of the wings, back 
of the mesopleural suture. 

Sternopleura, the lower part of the pleura, below the 
sternopleural suture and above the front coxa. 

Hypoplcura, the space over the middle and hind coxae, 
below the metapleura. 

Metapleura, the 'sides of the metanotum', a more or 
less swollen space at the outside of the metanotum and 
between it and the pteropleura and hypopleura. 

Metanotum, the oval, arched portion below or behind 
the scutellum. It is frequently most easily observable in 
flies with a long, slender abdomen, as the Tipulidae. 

Halteres, balancers or poisers, rudimentary posterior 
wings, a slender organ with a dilated head, situated be- 
low each metapleura. 

SquamcE, Tegulce or Calyptrce, a pair of membranous 
scales situated above the halteres and back of the root of 
the wings, one above the other. The lower one or both 
may be rudimentary or absent ; the upper one moves \vith 
the wings and is called the antitegula by Osten Sacken. 
Comstock, however, objects to this use of tegula, saying 
that the term was first used for the cup-like scale above 
the root of the wing in certain hymenoptera, and should 
5 


34 


NORTH AMERICAN DIPTERA. 


be reserved for that organ ; he calls them alula? , a term 
generally applied to the proximal posterior lobe of the 
wing. 


Fig. 9. Legs, i, leg of Tipnlid; 2, middle leg of Peckia prize eps, 
male; 3, hind foot of Mallophora scopipeda, male; 4, hind leg of 
Tropidia quadrata; 5, last tarsal joint of Dialysis; 6, front leg of 
Stegana hortz, male; 7, hind leg Rhopalomera cilia ta; 8, hind leg of 
Calotarsa, male. 

LEGS. 

The three pairs of legs are attached to the prothorax, 
mesothorax and metathorax, and are called, respectively 
the front, middle and hind pairs. When the front and 
middle pairs are spoken of together they should be call- 


LEGS. 


35 


ed, for the sake of exactness, the anterior legs ; when the 
middle and hind pairs are collectively meant, the poste- 
rior legs. The legs are composed of five parts: 

Coxa, the part attaching the legs proper to the thorax. 

Trochanter, the short, small, ring-like portion between 
the femur and coxa. 

Femur, almost invariably the longest and stoutest por- 
tion of the legs, often provided with tubercles, spines or 
projections or sometimes greatly thickened; usually 
slender. 

Tibia, the next part succeeding the femur, and like it 
often with various ornamentations or projections. When 
it terminates in one or more distinct, short, bristly spines, 
it is said t<5 be spurred. 

Tarsus, the distal division of the legs, composed (ex- 
cept in some abnormal forms) of five joints, of which the 
first, that next to the tibia, is called the metatarsus. On 
the terminal, or fifth joint, are the 

Ungues or claws, usually two, curved, movable hook- 
lets on the under side of the last tarsal joint, at the base 
of which below, are a pair of 

Pulvilli (fig. 10), two pad-like, flesh}* cushions attached 

to the last joint of the tarsus 
below the claw, usually pres- 
ent, but often absent among 
the Orthorrhapha and often 
much larger and better de- 
veloped in the male than the 
female. They are sometimes 
elongate, but are more usu- 
ally rounded, and provided 
with hairs. Between them is 
the 


Fig. 10. Claws and pulvilli of 
domestic fly. After Kellogg. 

Empodium, a median appendage on the under side of 
and between the claws, either in the form of a pad, like 
the pulvilli. (fig. 9-5 ), when it is called pulvilliform, or 
like a bristle or spine (see Asilidae, fig. 31), sometimes 


NORTH AMERICAN DIPTRRA. 

it is alone present and the pulvilli are wanting (see 
Bibionidse, fig. ya). 


Fig. ii. Male genitalia. i, Tipulidae (Diotrepha}\ 2 Tipulidae 
(Atarba]\ 3, Tipulidae (indet.); 4, Culicidse (Aedes]\ 5, Dolichopodi- 
dae (Dolicho/>i(s}\ 6, Asilirlse (^ 


ABDOMEN. 

The abdomen is composed of a variable number of seg- 
ments, more or less closely fused together. The normal 
number for insects, nine, are rarely all visible (the Tip- 
ulidse are examples). They are counted from the base 
on the upper side. In not a few cases the first two are 
so closely fused together, and the first one abbreviated, 
that the nomenclature leaves some doubt in the mind of 
the student. The upper part of the abdomen may be es- 
pecially indicated by the word dorsuni, but in general, the 


WINGS. 37 

venter or under part is alone thus contradistinguished, 
The male genitalia, which in many cases are of compli- 
cated structure, and of much value in classification, are 
known collectively as the hypopygium^ and this term is 
usually restricted to the male genitalia, though some- 
times used also for the female organs. The ovipositor of 
the female abdomen very frequently projects from the 
abdomen, and is sometimes extremely long; its structure 
may be characteristic of genera or families. The more 
detailed description of the parts of both these organs it 
is unnecessary to go into here; the}- may be studied in 
the different families, where the} 7 often find useful appli- 
cation in the separation of species, though rarely of 
genera. 


Fig. 12. Wing of Tabanns. 

WINGS. 

To understand the venation or neuration of the wings 
the student may select a common large horsefly (Taban- 
idae). Observe near the middle of the wing directed 
transversely, a large, oblong, five or six sided cell, sur- 
rounded on all sides by other cells. This is the discal 
cell and is present in nearly all flies. Somewhere on the 
vein (fourth longitudinal}, that bounds this cell in front, 
will be seen a short connecting vein, directed anteriorly, 


NORTH AMERICAN DIPTERA. 

the anterior, small or middle cross-vein (b), which is very 
constant in flies, and affords in most cases, a key to the 
venation, no matter how intricate. It connects with the 
third longitudinal vein in front (in a few cases the sec- 
ond longitudinal vein); the cell behind it is the discal, 
in front, between the second and third longitudinal veins, 
\he first sub marginal; on the outer side ihe first posterior; 
011 the inner side the first basal. Just back of the first 
basal cell and separated from it by the fourth longitud- 
inal vein, is the second basal cell; back of the second basal 
and separated by the fifth longitudinal vein, is the third 
basal or anal cell. Back of the anal cell and including 
the free posterior proximal portion of the wing is the ax- 
illary cell. In the horsefly the anal cell is seen to run back 
obliquely to near the posterior margin of the wing, where 
it terminates acutely, that is, the anal cell is closed near 
the border of the wing; should the two veins that close 
it run separately intc the margin of the wing, then the 
cell is said to be open. Counting from the third longi- 
tudinal vein (posterior branch) backward along the pos- 
terior border of the wing, to the vein that closes the anal 
cell outwardly, the student will count five different cells, 
the first of \vhich, as already said, borders on the first 
basal cell, the second and third on the discal cell, the 
fourth on the discal and second basal cell, and the fifth 
on the second basal and anal cells; these cells are called 
the posterior cells, and are numbered from before back; 
the first is bounded by the third and fourth longitudinal 
and the anterior cross-vein; the second posterior by the 
anterior branch of the fourth vein in front, its posterior 
branch internally and behind, often superfluously called 
the anterior intercalary vein ; the third posterior cell is 
bounded in front by the posterior branch of the fourth 
vein, internally by i\\e posterior cross vein (d], posteriorly by 
the anterior branch of the fifth vein; the fourth posterior 


WINGS. 39 

cell is bounded in front and internally by the anterior 
branch of the fifth vein, bordering the discal and basal 
cells, posteriorly by the posterior branch of the fifth, 
often also superfluously called the posterior intercalary 
vein ; this cell in other flies often borders on the discal 
cell alone internally; tio& fifth posterior cell is bounded in 
front by the posterior branch of the fifth vein, internally 
by the petiole of the fifth vein, posteriorly or internally 
by the posterior basal cross-vein. There is much doubt as 
to whether this latter is really a cross-vein in the more 
evident meaning of the word, or whether it really repre- 
sents the primary branch of the fifth vein, since in man)' 
flies this is the only termination of the vein, the anterior 
branches being wholly wanting. The short vein which 
separates the discal cell from the second basal cell is often 
called the anterior basal cross-vein; sometimes the discal 
cross-vein, which would be the better term, were it not to 
be confused with the posterior cross-vein itself. Follow- 
ing the third longitudinal vein outwardly it will be found 
to give off an anterior branch, which runs forward to ter- 
minate in the anterior marginal vein of the wing, the 
costa; the cell included in this fork, between the branch 
and the vein itself is called the second submarginal cell, 
and this name should always be restricted to the cell so 
bounded, though usually the cell enclosed between the 
branches of the second longitudinal vein in the Culicidae, 
Tipulidse, etc., receives this name. The second longi- 
tudinal vein borders the first submarginal cell in front 
and terminates in the costa, as the encompassing vein of 
the wing is called ; in a relatively few flies this vein also 
gives off a branch in front, dividing the marginal cell 
just as the submarginal cell is divided in Tabanus. Be- 
tween the first longitudinal vein, which has a similar 
course to that of the second longitudinal, though shorter, 
and the vein in front of it, between it and the costal bor- 


NORTH AMERICAN DIPTERA. 


der, and called the auxiliary vein, is the subcostal cell ; 
between the auxiliary vein and the costal border itself is 
the costal cell. 

Finally, near the root of the wing, a short, but very 
constant cross-vein connecting the auxiliary vein with 
the costa is the humeral cross-vein (a). 

The above is the nomenclature of the wing now having 
almost universal vogue among descriptive entomologists, 
a s}^stem which, with minor modifications, has been used 
almost from the beginning of descriptive dipterology. It 
has no especial superiority over other systems to com- 
mend it, nor has it any striking disadvantages to con- 


Fig. 13. Wing of Pangonia. Schiner's nomenclature. 

i, costal cell; 2, mediastinal cell; 3, subcostal cell; 4, 5, cubital cells; 
6, 7, 8, 9, n, first -fifth posterior cells; 12, discoidal cell; 13, 14, 15, 
first-third basal cells; 16, axillary cell. 

demn it; and long usage has apparently fixed it. An- 
other system in vogue at the present time among a few 
dipterological authorities is that used by Schiner in his 
later writings, and, which, could it displace the older 
system, would have much to commend it. It will be 
readily understood by the comparison of the tw r o figures 
given. The only confusion it makes with the older 
system is in the use of mediastinal cell for subcostal and 
subcostal for marginal, and this confusion is actually 
apparent in the writings of some authors, of whom Ver- 
rall is an example. 


WINGS. 


R 


R 


2-3 


R 


M 


Fig. 14. Wing of Silrins. Comstock-Needhain nomenclature. 

A third system is that proposed by Comstock and 
Needham about ten years ago, but which has found 
practically no acceptance among dipterologists, with the 
exception of one or two American writers. There is 
much to be said in favor of a universal system of nomen- 
clature among entomologists, a consummation devoutly 
to be wished. The present work, however, is no place 
for propagandism, and the common nomenclature has 
been everywhere employed in the following pages. The 
individual writer may do as he chooses in the use of 
either of the three systems, though he would do well to 
remember that ephemeral writings or briefer communi- 
cations will suffer by the use of any except the standard; 
only thorough monographic studies with abundant illus- 
trations will do much toward commanding the acceptance 
of either of the less used nomenclatures. I give below 
in tabular form the synonymy of the three systems for 
the Tabanus wing: 


Auxiliary vein . 
First longitudinal . 
Second longitudinal 
Third longitudinal . 
Fourth longitudinal 
Fifth longitudinal . 


II Subcostal 
llli Radial I . 
III3 Radial 3 . 
III4, 5 Radial 4, 5 
Vi,2 Cubital i, 2 
Y3 Cubital 3 . 


Mediastinal 

Subcostal 

Radial 

Cubital 

Discoidal 

Postical 


NORTH AMERICAN DIPTRRA. 


Fig- 


Rhyphus 

(Rhyphidae) 


Fig. 16. 


Enlonchus 

(Cyrtidse) 


Fig. 17. 

Pantarbes 

(Bombyliidse) 


Fig. 18. 

Con ops 

(Conopidae) 


Fig. 19. 

[/,+. Scenopinits 

(Scenopinidae) 


Fig. 20. 

Rhamphomyia 

(Empididae.) 


Venation, after Comstock and Needham, 


VESTITURE. 


43 


Sixth longitudinal . 

Humeral cross-vein 

Anterior cross-vein . 

Posterior cross-vein 

Anterior basal or discal cross-vein 

Costal cell .... 

Subcostal cell .... 

Marginal cell .... 

First submarginal cell 

Second submarginal cell 

First basal cell . . , 

Second basal cell 

Anal cell ..... 

Axillary cell .... 

First posterior cell . 

Second posterior cell 

Third posterior cell 

Fourth posterior cell 

Fifth posterior cell . 

Discal cell 


IX Anal .... Anal 

(v) Basal cross-vein 

(w] Median cross-vein 

(x] Posterior cross-vein 

(y] Discoidal cross-vein 

2ndl Costal 

II .... Mediastinal 

III .... Subcostal 

1113 . . . First cubital 

1114 . . . Second cubital 
2ndIII . . . First basal 

V ... Second basal 

VIII . . . . Third basal 

IX ... Axillary 

1115 . . . First posterior 

VI . . . Second posterior 
2ndV2 . . Third posterior 
\~3 . . . Fourth posterior 
VIII . . . Fifth posterior 
ist V2 Discoidal 


VESTITURE. 

Flies differ much in the nature of their vestiture. 
Many are nearly or quite bare; others have a thick, 
woolly covering of closely set, fine hair; while others 
still are covered abundantly with a long, stout and heavy 
bristles or macrochaetae. Doubtless the vestiture has an 
intimate relation with the habits of the mature insect; 
just what the relations of the different kinds are, is 
not yet well understood. Osten Sacken has observed that 
the eremochaetous kinds (that is those diptera in which 
there is a general absence of bristles, as, for example, 
the Stratiomyidae, Leptidae and Tabanidae) are, for the 
most part, holoptic in the male sex, and at the same time 
are chiefly aerial in habit, flying swiftly and often hov- 
ering, using the legs only for alighting and resting. On 
the contrary, the chaetophorous flies (as the Muscidae in 
the wide sense, Phoridae, Dolichopodidae, Asilidae, etc.) 


44 


NORTH AMERICAN DIPTRRA. 


are for the most part ambulatory insects, using their legs 
as much as, sometimes more than the wings in locomo- 
tion ; or, if not, for grasping, seizing or holding their 
prey; they seldom have the eyes contiguous in the male 
sex. Probably the macrochsetse reach their highest de- 
velopment among the Tachinidae, as for instance in 


Fig. 21. Paradejeania, sp. (Brazil). Enlarged. 

Dejeania, Paradejeania, etc., and the Dexiidae (Hys- 
trichodexia}, where the abdomen may be almost covered 
with long, erect, very rigid spines. 

As concerns other kinds of vestiture, the usage of 
writers is not very exact; the terms hair, pile, pubes- 
cence, tomentum, being used with a wide degree of lati- 
tude. In general, however, pile should be restricted to 
indicate closely and thickly set, erect, fine hair like the 
pile of velvet; while the term hair may be used to desig- 
nate longer, less erect, and less abundant pelage. Pu- 


CH^ETOTAXY. 

bescence should be restricted to short, recumbent, fine 
hairs, while tomentum can only correctly be used as the 
designation for flattened, scale-like or stubble-like, more 
or less recumbent hairs, which gradually merge into dust 
or pollen, which is so generally present in diptera, and 
upon which the determination of many species must 
largely depend. 

CH^ETOTAXY. 

Many years ago Rondani proposed the term macrochtz- 
t(E for the large, differentiated bristles of flies, and sug- 
gested their use in classification, though he made but 
little use of them himself. L,oew also failed to appre- 
ciate their full significance in the classification of diptera, 
although he made considerable use of them, examples of 
which may be found in his diagnostic characterization of 
the Helornyzidse and Ortalidae. It was Osten Sacken 
who proposed the term ch&totaxy to designate the science 
of their arrangement, and who published an epoch-mak- 
ing paper on the subject in 1881. Girschner, later, ex- 
tended the system more widely for the calyptrate diptera. 
At the present time a thorough knowledge of chaetotaxy 
is indispensable for all who would deal with those fami- 
lies, especially of the Cyclorrhapha, in which they are, 
for the most part, so conspicuous, and upon which the 
generic and specific distributions so much depend. Osten 
Sacken, indeed, makes the arrangement of the bristles 
almost fundamental as indices of relationships, and exag- 
gerates their importance in some instances, especially so 
when he would locate the Apioceridse with the Asilidse, 
almost solely on their chaetophorous character. Hilari- 
morpha he refuses admission to the Empididse chiefly be- 
cause of the absence of bristles, forgetting that some true 
Empididse also absolutely lack bristles. However it 
may be in particular instances, there can be no question 
6 


46 NORTH AMERICAN DIPTERA. 

but that the number and arrangement of bristles in most 
cases offer important, in some cases perhaps the only, 
available criteria in generic classification. For that rea- 
son it behooves the student to become familiar with the 
subject, and to pay especial attention to their use in 
many, if not most of the groups. 

CEPHALIC BRISTLES. 

Vertical, two pairs, inner and outer, inserted more or 
less behind the upper and inner corner of the eye, erect 
or the inner pair convergent, the outer divergent; the 
outer pair is usually the smaller and more frequently 
absent. 

Postvertical ' , in the middle, near or back of the vertex, 
convergent, erect or divergent; usually small, and often 
absent. 

Ocellar, situated close to the ocelli, usually the foremost 
ocellus; usually directed forward; often minute or absent. 

Frontal, a row of bristles on either side of the median 
vitta descending often to or below the root of the anten- 
nae on the side of the face anteriorly; of much use in the 
classification of the Calypterse. 

Pronto-orbital, a bristle or bristles on each side of the 
front near the orbit, immediately below the vertical bris- 
tles ; there may be one, two, or none on each side. 

Lower fronto-orbital, situated on the lower part of the 
front near the eyes, and not quite in line with the fronto- 
orbitals. They are not of frequent occurrence. 

Cruciate, a pair of bristles in the middle of the lower 
part of the front, directed inwardly and forwardly; ob- 
served in some Calypterae and Acalypterse. 

Vibrissa, a stout bristle situated near or a little above 
the oral margin, near the front edge of the mouth open- 
ing; of important use in the classification of the Acalyp- 
terae. 

Facia/, a series of bristles on either side of the middle 


MESONOTAL BRISTLES. 


47 


of the face, above the vibrissa, especially conspicuous 
among many genera of the Tachinidse, but usually ab- 
sent in the Acalypterae. 

Lateral facial, one or two bristles sometimes present on 
the sides of the face below, toward the eye. 

Postorbital, a line of small bristles nearly parallel with 
the posterior margin of the eye, on the edge of the occiput. 

MESONOTAL BRISTLES. 

Humeral (Inn), one or 
more bristles inserted on 
the humeral callus. 

Posthumeral (ph), one or 
more bristles situated on 
the inner margin of the 
humeral callosity. 

Notopleural (npl) , usual- 
ly two, inserted immedi- 
ately above the dorsopleu- 
ral suture, between the 
humeral callus and the 


pa 


Fig. 22. Mesonotal bristles. 


root of the wing, on the 
bottom of the presutural 
I depression. 

Presutural (pr), one or more bristles situated immedi- 
ately in front of the transverse suture, above the presu- 
tural depression. 

Supraalar (saj, usually one to three bristles above the 
root of the wings, between the notopleural and postalar 
bristles. 

Intraalar (ia), a row or two or three bristles between 
the supraalar group and the dorsocentral bristles. 

Postalai (pa], bristles on the postalar callus, back of 
the supraalar. 

Dorsocentral (dc), a row on the inner part of the dorsum, 
at the outer side of the acrostichal. 

Acrostichal (a), a row next to the median line, on the 
inner side of the dorsocentral; sometimes both the dorso- 


48 NORTH AMERICAN DIPTERA. 

central and acrostichal are represented by the hindmost 
bristles forming a prescutellar row in front of the scutel- 
lum. 

Scutellar, bristles along the margin of the scutellum, 
which may be distinguished from the Dorsoscutellar. 

PLEURAL BRISTLES. 

Propleural, a bristle or bristles inserted on the lower 
part of the propleura, immediately above the front coxa. 

Mesopleural, bristles inserted on the mesopleura, near 
the angle formed by the dorsopleural and mesopleural 
sutures. 

Sternopleurdl, one or several bristles below the sterno- 
pleural suture; mesothoracic of Loew. 

Pteropleural, bristles inserted on the pteropleura, rarely 
present and difficult to distinguish. 

Metapleural, bristles inserted on the metapleura, es- 
pecially conspicuous in the Asilidae, and named by 
Lynch the 

Trichostical bristles, a fan-like row on the metapleura, 
conspicuous in some families. 

Hypopleural bristles, a row or tuft of usually small bris- 
tles on the hypopleura, occurring in the Tachinidae, 
Dexiidae, Sarcophagidae, and a part of the Muscidae, first 
recognized by Osten Sacken. 

ABDOMINAL BRISTLES. 

Marginal bristles, bristles inserted on the posterior 
margins of the segments above, especially conspicuous 
in many Tachinidae. 

Discal bristles, usually one or more pairs inserted near 
the middle of the segments before the hind margins. 

Lateral bristles, one or more bristles situated on or 
near the lateral margins of the segments. 

In addition, a number of terms are used to designate 
the inclination of the bristles, often important in describ- 
ing the cephalic bristles. The more important of these 


INTERNAL ANATOMY. 


49 


are: erect, when standing perpendicularly or nearly so; 
prodinate, when directed forward ; reclinate when directed 
backward ; divaricate or divergent when directed outward 
from the middle line; convergent when directed inwardly; 
decussate or cruciate when crossing each other. 

INTERNAL ANATOMY. 

For the following brief account of the internal anatomy 
of Diptera I am indebted to Prof. V. L. Kellogg. 

The special features of the internal structure of the 
Diptera are the high degree of concentration of the nerv- 
ous system attained in some of the members of the order, 
the expansion of the two main tracheal trunks in the base 
of the abdomen to form air sacs, the presence of a suck- 
ing stomach as in the Lepidoptera, the constant number 
(four, rarely five) of the Malphigian tubes, and the ab- 
sence of a bursa copulatrix in the females. 

The alimentary canal presents behind the oesophagus 
an expansion which is a crop or sucking stomach. The 
ventriculus, or true stomach, lying behind it, has usually 
two caeca; and the long, slender, Malphigian vessels are, 
in almost all species, four in number, a surprising con- 
stancy compared with the condition in other groups of 
specialized insects. The vessels open singly into the ali- 
mentary canal in some flies and in others they unite in 
pairs before reaching the canal and open into it by two 
ducts. 

The heart is of the usual type, but with only two cham- 
bers in the more specialized families, owing to the con- 
centration of the bod}\ In the larva of Corethra the heart 
is a simple, elongate tube without chambers. 

The two main tracheal trunks expand at the base of 
the abdomen into conspicuous air sacs similar to those 
found among Hymenoptera, Lepidoptera, the lamellicorn 
beetles and some other insects. The two pairs of spira- 


50 NORTH AMERICAN DIPTERA. 

cles of the thorax are provided with 'vocal cords', and a 
considerable part of the humming sound is produced by 
those structures. The abdominal spiracles of some flies 
are as primitive as are to be found among insects, being 
simply unlipped openings. 

The condition of the nervous system varies greatly 
within the order. In the elongate, more generalized ne- 
matocerous forms there are five or six abdominal ganglia, 
and three distinct thoracic ganglia. From this condition 
to that shown by the Muscidse, where all the thoracic 
and abdominal ganglia are united into one large gang- 
lion in the thorax, a most instructive series of gradatory 
forms is presented. In the Empididse, which stand in- 
termediately as regards the concentration of the ventral 
cord, the two anterior thoracic ganglia are fused into 
one ; this condition is radically different from that shown 
by insects of other orders, as the Coleoptera, L,epidcp- 
tera and Hymenoptera, which have but two thoracic 
ganglia. In these insects, however, it is the two poste- 
rior ganglia (meso- and metathoracic) which are fused 
into one. 

The studies of Child on the so-called Johnston's organ 
(located in the second aiitennal joint), an elaborate struc- 
ture of fine chitin rods connected with special nerve cells 
and these connected by fine nerves with the main anten- 
nal nerve, seem to ascribe definitely an auditory function 
to the antennae. Kellogg has shown that the divided 
eyes of such flies as the Blepharoceridae and others (in- 
dicated externally by the division of the corneal facets 
into two regions in which the facets are of different size) 
are in reality made up two types of ommatidia, one type 
being much larger and much less strongly supplied with 
retinal pigment than the other type. This condition pro- 
duces a certain sort of differentiation of the visual func- 
tion, one part of the eye being better adapted for seeing 


CLASSIFICATION OF DIPTERA. 5I 

swiftly moving objects, or in twilight than the other, but 
the other part better adapted for the formation of a pre- 
cise image. 

Special nerve structures are present at the base of the 
halteres, and orienting, auditory and other sense func- 
tions have been ascribed to these organs by various mor- 
phologists. Flies from which these organs have been 
removed are utterly unable properly to direct their flight. 

The internal organs of the reproductive system present 
some interesting peculiarities. The ovaries of the female 
consist of an exceptionally large number of egg-tubes. 
There are three spermathecse, paired accessory organs, 
and no true bursa copulatrix. The males have two oval 
testes with short vasa defferentia. The testes are not 
infrequently colored, possessing a pigment layer. There 
is a well developed penis with accessory copulatory or- 
gans. Snodgrass' interesting studies on the comparative 
anatomy of the external genital organs show that while 
there may be great variety in these structures among the 
males of any one family, the females, curious!}' enough, 
show a remarkable uniformity of the hypopygial organs. 

CLASSIFICATION OF DIPTERA. 

The first real attempt at the subdivision of the order of 
Diptera was made by Latreille in 1805, when he distin- 
guished between the nematocerous and brachycerous 
forms. The term Nemocera was introduced by him in 
1817, and the characters upon \vhich he based the group 
are yet employed. The name Brachocera was applied to 
the remaining Diptera by Macquart in 1834. The char- 
acters he used, following Latreille, were : 

Antennae at least six-jointed; palpi four or five-jointed. Nemocera. 
Antennae three-jointed; palpi one or two-jointed. Brachycera. 

This attempt at subdivision, based upon the antennae 
and palpi, was all that had been made until a compara- 


5 2 NORTH AMERICAN DIPTERA. 

tively recent date. It is the classification followed by 
Loew in the first volume of the Monographs published as 
late as 1862. In 1863 Brauer proposed a more rational 
division of the Diptera into the two suborders, Ortho- 
rrhapha and Cyclorrhapha, based chiefly upon larval and 
pupal characters. Their characters in a later publica- 
tion he gives as follows: 

Larvae with a 'jaw-capsule' (Kieferkapsel) or a differentiated head. 
Pupae free or enclosed in the larval skin; in either case the larval skin 
bursts for the extrication of the pupa or imago in a T-shaped opening 
on the back of the anterior end, or rarely in a transverse rent between 
the eighth and ninth abdominal rings. The imago lacks the frontal 
lunule and ptilinum. ...... Orthorrhapha. 

Larvae without differentiated head. Pupae always enclosed in the 
hardened larval skin (forming the so-called puparium) ; the imago al- 
ways escaping from the anterior end through a circular orifice. Frontal 
lunule present; ptilinum usually present. . . Cyclorrhapha. 

More recently Brauer proposed a further subdivision 
of the suborders into tribes and groups as follows: 

BRAUER'S CLASSIFICATION. 
Suborder Orthorrhapha. 
Section I. Nematocera. 

Tribe I. Eucephala. Families Mycetophilidae, Bibionidae, Chi- 
ronomidae,Culicidae, Blepharoceridae, Simuliidae, Psychodidae, 
Ptychopteridae, Rhyphidae. 

Tribe 2. Oligoneura. Family Cecidomyidae. 
Tribe 3. Polyneura. Tipulidae, Linmobiidae. 
Section II. Brachycera. 

Tribe 4. Acroptera. Family Lonchopteridae. 
Tribe 5. Platygenya. 

Group i. Homoodactyla. 

Superfamily i. Notacantha. Families Stratiomyidae, 
Xylophagidae. 

Superfamily 2. Tanystoma. Families Tabanidae, Acan- 
thomeridae, Leptidae. 

Superfamily 3. Bombylimorpha. Families Nemistrin- 
idae, Acroceridae. 

Group 2. Heterodactyla. 

Superfamily i. Procephala. Families Mydaidae, Asil- 
idse, Bombyliidae. 

Tribe 6. Orthogenya. Families Empidae, Dolichopodidae. 


CLASSIFICATION OF DIPTERA* 53 

Suborder Cylorrhapha. 
Section I. Aschiza. 

Tribe i. Syrphidse. Families Syrphidae, Pipunculidae. 
Tribe 2. Hypocera. Families Phoridae, Platypezidse. 
vSection II. Schizophora. 
Tribe 3. Eumyidse. 

Superfamily Schizometopa. Calypterasof the present work. 
Superfamily Holometopa. Acah T pterae of the present work. 
Tribe 4. Pupipara. Pupipara of authors, Eproboscidea. 

SCHINER'S CLASSIFICATION. 
Orthorhapha. 
Nematocera. 

Oligonenra Cecidomyidae, Mycetophilidae, Simulidae, Bi- 

bionidae. 
Polyneura Chironotnidae, Blepharoceridae, Psychodidae, Cu- 

licidae, Tipulidie, Dexidae, Rhyphidae. 
Brachocera. 

Cyclocera Stratiomyidae, Xylophagidae, Coenomyidse, Acan- 

thomeridae, Tabanidae. 

Orthocera Nemistrinidae, Bombylidae, Acroceridae, There- 
vidae, Midasidae, Asilidae, Leptidae, Empidae, Dolichopidae. 
Cyclorhapha. 
Proboscidea. 

Hypocera Phoridae. 
Orthocera. 
Oligoneura. 

Muscidae acalypterae Borborinae, Phycodrominae, Scato- 
phaginae, Thyreophinae, Rhopalomerinae, Helomyzinae, 
Dryomyzinae, Sciomyzinae, Tetanocerinae, Geomyzinae, 
Drosophilinae, Ephydrinae, Chloropinae, Psilinae, Sep- 
sinae, Calobatinae, Michogastrinae, Achinae, Diopsidinae, 
Dacinae, Trypetinae, Sapromyzinae, Ulidinae, Plat} T sto- 
minae, Dorycerinas, Pyrgotinse, Ortalinae, Agromyzinae, 
Milichinae, Ochthiphilinae, Heteroneurinae, Cordylu- 
rinae. 
Muscidae calypterae Tachininae, Muscinae, Dexinae, Sar- 

cophagime, Anthomyinae. 
Oestridae. 

Polyneura Platypezidae, Pipunculidae, Syrphidae, Conopidae. 
Eproboscidea Hippoboscidae, Nycteribidae. 


54 


NORTH AMERICAN DIPTKRA. 


OSTEN SACKEN'S CLASSIFICATION. 

Osten Sacken has offered many pertinent criticisms of 
Brauer's classification, insisting that the Nemocera and 
Brachycera are divisions of more fundamental importance 
than was assigned to them by Brauer. His classification, 
so far as it was developed by him, is as follows: 

Suborder Orthorrhapha Nematocera. Palpi usually four or five-jointed, 
pendulous and more or less filiform. Antennae many jointed (more 
than six-jointed), usually filiform (seldom pectinate), with the 
majority of the joints of the flagellum homologous (homomor- 
phous) . 

Superfamily Nemocera Vera. Males dichoptic;* no bisection or 
bicoloration of the eyes. Antennae provided with sensitive hairs 
arranged symmetrically on the flagellum in verticils or pencils 
(except Mycetophilidse) . No pulvilli;t empodia often, but 
not always present. 

A. Larvae peripneustic,| always terrestrial. Cecidomyidae, My- 
cetophilidae. 

B. Larvae peripneustic or amphipneustic, aquatic, subaquatic, 
sometimes terrestrial. Culicidae, Chironomidae, Psychodidae, 
Dixidae, Tipulidae. 

Superfamily Nemocera Anomala. Diptera with homologous (ho- 
momorphous) joints to the flagellum; usually four-jointed paipi. 
Males frequently holoptic, sometimes the females also. Pulvilli 
usually present. Antennae withoiit sensitive hairs. Ocelli usually 
present. Bibionidae, Simulidae, Blepharoceridae. Rhyphidaa, 
Orphnephilidae. 

Suborder Orthorrhapha Brachycera. Palpi not more than two-jointed, 
not pendulous, the end joint more or less clavate, and larger than 
the basal one; joints of the antennal flagellum, with rare excep- 
tions, not homologous. 

Superfamily Eremochaeta. No macrochaetae. Three well developed 
pulvilli. Males predominately holoptic, the eyes often bisected. 
Antennal flagellum polymorphous. Axillary incision, alula and 
antitegula in most cases distinctly developed. Discal cell usual- 

*They are sometimes truly holoptic. 

tRecent investigations show that true pulvilli are sometimes present. 

J Amphipneustic larvae are those in which the spiracles are con- 
fined to the first and last segments: metapneustic those in which they 
are confined to the posterior segments; peripncnstic those in which 
they are present on the median rings. 


CLASSIFICATION OF DIPTERA. 


55 


ly developed; usually five posterior cells. Legs rather smooth. 

Stratiomyidae, Tabanidae, Acanthomeridae, Leptidae. 
Superfamily Tromoptera. Chiefly hovering flies. Nemistrinidae, 

Bombyliidae, Cyrtidae, Therevidae, Scenopinidae. 
Superfamily Energopoda. Pedestrian flies. Asilidae, Dolichopod- 

idae, Lonchopteridae, probably Phoridae. 
Superfamily Mydaidae. Mydaidae. 
Suborder Cyclorrhapha Athericera. All other flies. 

COQUILLETT'S CLASSIFICATION 1901. 

Recently Mr. D. W. Coquillett has proposed another 
system, differing from any preceding one, and for the 
most part with new names, as follows: 

Suborder Eproboscidea Latreille. 

Families Hippoboscidae, Nycteribidae. 
Suborder Proboscidea Latreille. 

Section Orthorrhapha Brauer. 

Subsection Nemocera Latreille. 

Superfamily Tipuloidea Coquillett. 

Families Tipulidas, Dixidae, Culicidae, Psychodidae, 
Stenoxenidas, Chironomidae, Cecidomyidae, 

Mvcetophilidae. 
Superfamily Bibionoidea Coquillett. 

Families Bibionidas, Simulidae, Orphnephil- 

idaa, Belpharoceridae, Rhyphidas. 
Subsection Brachycera Macquart. 

Superfamily Tabanoidea Coquillett. ' 

Families Leptidas, Stratiomyidae, Acanthomeridae 

Tabanidae, Acroceridae, Nemistrinidae. 
Superfamily Bombyloidea Coquillett. 

Families Apioceridae, Mydaidae, Bombylidae. 
Superfamily Asiloidea Coquillett. 

Families Scenopinidae, Therevidae, Asilidae, Empidae 

Dolichopodidae. 
Superfamily Phoroidea Coquillett. 

Families Lonchopteridae, Phoridae. 
Section Cyclorrhapha Brauer. 

Superfamily Syrphoidea Coquillett, 

Families Platypezidae, Pipunculidae, Syrphidae, 
Conopidae. 


5 6 NORTH AMERICAN DIPTERA. 

Superfamily Muscoidea Coquillett. 
Group Calypteratae Desvoidy. 

Families Oestridae, Tachinidae, Dexidae, Sar- 

cophagidse, Muscidae, Anthomyidae. 
Group Acalypterae Macquart. 

Families Scatophagidae, Heteroneuridae, Helo- 
myzidae, Phycodromidae, Sciomyzidae,Sap- 
romyzidae, L,oncbaeidae, Ortalidas, Trypet- 
idae, Micropezidae, Sepsidae, P s i 1 i d ae, 
Diopsidae, Oscinidae, Drosophilidae, Geo- 
myzidae, Agromyzidse, Borboridae. 

LAMEERE'S CLASSIFICATION. 

Yet another pretentious scheme of the classification of 
Diptera is that of Prof. Aug. L,ameere of the Univer- 
sity of Brussels, which has very recently appeared.* 
The meritorious part of this ambitious attempt is the 
endeavor to apply the only real criteria in a true classifi- 
cation of insects, phylogeny. The author, however, is 
in deeper water than he suspected; but the scheme is 
worthy of reproduction because of several suggestions, 
though its inconsistencies clearly show that the author 

has not a wide acquaintance with the order. 


NEMOCERA. 
Polyneura. 
Culicidae. 


Ptychopterinae. 

Ptychopterini. 

Psychodini. 
Culicinae. 

Dixini. 

Culicini. 

Chironomini. 
Tipulidae. 

Ljmobiinae. 
Tipulinae. 


Oligoneura. 


Mycetopbilidae. 

Mycetopbilinae. 
Mycetobiinae. 
Cecidomyidae. 
Sciarinae. 
Cecidomyinae. 
L/estremini. 
Cecidomyini. 
Heteropezini. 


Mem. Soc. Ent. de Belg. xii, 1906. 105. 


CLASSIFICATION OF DIPTKRA. 


5*-r 
/ 


BRACHYCERA. 
Metagnatha. 
Rhyphidae. 
Bibionidae. 

Bibioninae. 
Bibionini. 
Simuliini. 
Orphephilinae. 
Blepharocerinae. 
Metarhyncha. 

Homceodactyla. 
Stratiomyidae. 

Xylophaginae. 
Stratiomyinae. 
Leptidae. 

Leptinae. 
Nemistrinae. 
Tabanidae. 

Tabaninae. 
Acrocerinae. 
Heterodactyla. 
Pleroneiira. 
Therevidae. 
Therevinae. 
Therevini. 
Scenopinini. 
Apiocerinae. 


I have given these more pretentious systems of classi- 
fication of the diptera in order that the tyro in their study 
may not reach the erroneous conclusion that any system 
is authoritative. Frankly, I do not have a great deal of 
faith in any of them. They are, in part at least, the bi- 
ased personal opinions of their authors, their individual 
views as to the importance of the different characters, 
opinions which can only reach an approximate equilib- 
rium after we have a much greater knowledge of ancient 
types, and perhaps of the embryology of modern forms. 
Upon the whole, Osten Sacken has brought a wealth of 
7 


Bombylidae. 

Anthracinae. 

Bombylinae. 
Asilidae. 

Asilinae. 
Midinae (sic). 
Eremoneura. 

Orthorrhapha. 
Kmpididae. 

Empidinae. 
Hybotinae. 
Dolichopodidae. 
Diaphorinse. 
Dolichopodinae. 
Cyclorrhapha. 
Syrpharia. 

Platypezidae. 
Lonchopteridae. 
Phoridae. 
Pipunculidae. 
Syrphidae. 
Myodaria. 

Conopidae. 
Muscidae. 


NORTH AMERICAN DIPTERA. 

information to bear upon his views, though he by no 
means claimed finality for them. His exceptions, how- 
ever, are so many and oftentimes so pertinent that I am 
by no means convinced about many things. Wherein 
all writers concur may safely be accepted by the stu- 
dent ex authoritate , but I would advise the inexpert 
student to make no use of most of the terms that have 
been proposed; nor fret himself about the value of any of 
them. The divisions Orthorrhapha and Cyclorrhapha 
may perhaps safely be accepted, since all, or nearly all, 
are agreed thereon, though by no means agreed as to 
their rank and limits. At one time, indeed, they were 
almost universally accepted as the two chief suborders, 
but within recent years there has been a tendency to sub- 
ordinate them to the older groupings of Latreille and 
Macquart, perhaps in part due to the influence of Osten 
Sacken's authority. Osten Sacken endeavored to show 
that the characters recognized as distinctive of the Ne- 
mocera and Brachycera are of more fundamental import- 
ance than those distinguishing the Orthorrhapha and 
Cyclorrhapha. With this view I do not agree. I must 
still accept Brauer's chief divisions, as, upon the whole, 
the most natural grouping of the order. 

Speiser believes that the Pupipara are only highly 
specialized muscids, and it is even doubtful yet whether 
some of them may not be oviparous in habit; we know 
of one species, at least, wingless and parasitic upon birds 
which stands on the border line. Wesche has recently 
asserted that the mouth-parts of the Pupipara are thor- 
oughly muscid in structure. The vestigial eyes, small 
and partly aborted antennae, bristly head, leathery abdo- 
men and short stout legs are also characteristic of certain 
wingless, parasitic Phoridae, and certainly no one will 
attempt to trace any immediate relationship with these 
flies. I believe there is a much closer relationship be- 


CLASSIFICATION OF DIPTERA 59 

tween the Streblidae and Borboridae, than between the 
Borboridae and Empididae, for instance. 

I must insist, notwithstanding Osten Sacken's rather 
strongly asserted views to the contrary, that there is no 
distinct limitation between the Nemocera and Brachycera. 
If the reader will turn to the characters given in the fam- 
ily table further on, he will, I believe, appreciate the 
force of my statement. The antennae of Rhachicerus, a 
'brachycerous' fly, are in some respects among the most 
primitive or generalized of all diptera : we know of no 
living genus, unless it be Cerozodia, from which it could 
have been derived; doubtless some ancient tipulid may 
have been the forbear of the genus. Of course we can 
not positively say that these insects may not have revert- 
ed in the structure of the antennae from a specialized to 
a generalized condition, but that is very improbable in- 
deed evolution is irreversible. It would seem, however, 
that all the Brachycera, save possibly Rhachicerus^ have 
been evolved from a common ancestor, otherwise we are 
at a loss to explain the seemingly strange fact that the 
number eight is so common for the segments of the fla- 
gelltim, and is never exceeded, with the above exception. 
If the 'posterior cross-vein' of the Brachycera is identi- 
cal with the vein at the outer end of the discal cell in the 
Tipulidae and Rhyphidae, then it is apparent that all 
families, save these, of the Nemocera, are excluded from 
the ancestral line of the Brachycera. 

Lameere, indeed, would divide the Nemocera and Bra- 
chycera between the Mycetophilildae and Bibionidae. 
But that is only begging the question, the two families 
are absolutely coalescent. The fact is that the structure 
of the head, antennae, and palpi changes so gradually 
from the more generalized to the more specialized forms 
that nowhere can we draw an impassable line between 
the groups. 


60 NORTH AMERICAN DIPTERA. 

On the other hand the structure of the adult insects 
changes so much somewhere in the vicinity of the Syr- 
phidse, to say nothing of larval structure and habits, that 
I believe, if we must have suborders (which to me does 
not seem imperatively necessary) the place to make 
the division is somewhere between the Syrphidse and 
Dolichopodidae. There are groups here which are oscul- 
ant no doubt a lot of ink has been wasted in their dis- 
cussion, but so there are in all classifications. The 
sooner we learn, as learn we must, that dividing lines do 
not occur in nature except as accidents, that evolution 
never classified anything and never will, the sooner we 
shall get over some of the bugbears of taxonomy. The 
best we can do is to make such groupings as will express 
most clearly and most conveniently relationships, and 
especially the phylogeny of organisms. 

As I have already said, a true classification of the dip- 
tera, as of all other organisms, is desirable, but not pos- 
sible, for that would mean the absolute perfection of 
dipterological science. An approximation to that finish- 
ed perfection is of course attainable, but that approxima- 
tion must depend upon many factors which have as yet 
scarcely engaged the attention of students of diptera. 
Their embryology, geological history, geographic dis- 
tribution, ethology and comparative anatomy, are among 
these factors. No dipterologist has ever given serious 
attention to the study of extinct forms, and no classifica- 
tion of any group of organisms has ever been satisfactory 
until such forms have been considered and seriously con- 
sidered, paleontology and embryology especially, are 
the sine qua non of any entomological classification, and, 
considering the relatively slight advances which have 
been made in the taxonomy of the diptera during the 
past half century, now seems the opportune time for such 
studies. What dipterologist will undertake them ? 


CLASSIFICATION OF DIPTERA. 6! 

Without extending these remarks to an undue length 
it may be well to set down here the chief lines of evolu- 
tion in diptera. As they seem to me they are as follows: 

1. Reduction in the number of longitudinal veins from the primitive 

eight or nine; and of their branches. 

2. Shortening of the most anterior and posterior of these, and the re- 

duction of the basal cells. 

3. Weakening of the posterior veins; loss of the marginal vein behind; 

loss of the primitive cross-veins. Powerful flyers with strong 
orienting powers have a supporting venation before the hind 
margin, produced either by adventitious cross-veins or the 
closure of cells. 

4. Loss of antennal joints from thirty or more to three or two, 

by reduction in number of homologous joints; by the progress- 
ive fusion of the distal joints into the so-called 'complex'; or 
into the style or arista; or by the atrophy of the basal joint. 
The development in size of the simplified antenna; or the 
production of structural peculiarities. 

5. Loss of palpal joints, and, as in the antennae, the development of 

the simplified palpus. 

6. The development of holopticism from a primitive clichopticism. I 

do not believe that the reverse is probable the Acalypterae 
have not descended from the Calypterse, for instance, and these 
latter are, in this respect at least, as in others, the more highly 
.specialized insects, just as Bibio is more highly specialized than 
Mycetophila. 

7. LOSS of ocelli; diminution and loss of the compound eyes, espe- 

cially characteristic of ectoparasites. 

8. Diminution in number of abdominal segments; the closer fusion of 

the thoracic segments. 

9. Loss of tarsal joints; loss of empodium. 

These of course are not all the lines of evolution in 
diptera, but I believe that they are all irreversible, that 
evolution has never recovered anything once function- 
ally lost. Moreover all, or nearly all these lines of evo- 
lution are polyphyletic, resulting in numerous cases of 
parallel resemblances which must be taken into account 
in an} 7 attempt at true classification. Heteropeza among 


6 2 NORTH AMERICAN DIPTERA. 

the Cecidomyidae is an excellent example of extraordina- 
ry reduction of wing veins, palpal joints and tarsal joints, 
though it still retains the primitive antennae and other 
primitive characters which ally it with the more gener- 
alized forms of diptera. In other words, the evolution of 
characters in the different lines of descent does not pro- 
ceed pari passu, and opinions will always differ as to the 
different values to be assigned to the specialized char- 
acters. Nycteribia and Melophagus are perhaps the most 
highly specialized of all insects, that is they have traveled 
further from the starting point. We do not for that 
reason deem them the most typical of insects, the most 
highly developed far from it. 

COLLECTION AND PRESERVATION 
OF DIPTERA. 

Flies must be collected with much more care than can 
be safely used with such insects as coleoptera. Moisture 
of all kinds injures or ruins them, and specimens collected 
in alcohol are worthless. For this reason the collecting 
bottle should be lined throughout with blotting paper, 
and the cyanide placed in the cork ; a very little poison 
suffices to kill them. Nor should they be allowed to be- 
come too dry before pinning. The pin should be thrust 
through the middle of the thorax, and the specimen 
placed just so as to enable the head of the pin to be grasp- 
ed by the thumb and finger safely. Very small speci- 
mens should never be glued to card points, as is commonly 
done with coleoptera; they should always be pinned. 
Sometimes specimens may be collected and packed in 
some very fine, light sawdust impregnated with carbolic 
acid, where it is inconvenient or impossible to pin them. 
Such specimens being gently separated from the sawdust 
are allowed to remain for some hours, over, but not 
touching, damp sand before pinning. To pin the small 


COLLECTION AND PRESERVATION OF DIPTERA. 63 

specimens, use narrow strips of good card-board or blot- 
ting paper, thrusting a slender pin through one end and 
allowing it to protrude just a little above the edge and 
clipping off the longer end with a pair of pliers. Thrust 
the point of the pin as held in the card-board, into the 
under-side of the insect, but not entirely through it, and 
a stronger pin in the reverse direction through the other 
end of the small strip. The pins are to be thrust through 
the card-board from edge to edge, and in consequence a 
good quality is to be selected that will not split too read- 
ily. The wings should never be spread, but should be 
turned aside so as not to conceal the abdomen. In the 
early part of the season many interesting species will be 
caught with the beating-net. The pointed end of the 
beating-net may be thrust, with its contents, into a bot- 
tle containing a little chloroform, or into a cyanide bot- 
tle, for a short time, when the specimens may be leisurely 
removed. Later in the season, flower-flies will be col- 
lected from a great variety of melliferous blossoms, and 
it is better to wait for the specimens to come to such blos- 
soms than to go hastily about looking for them. I have 
collected from a single patch of elderberry blossoms, not 
a rod in diameter, more than forty species ot Syrphidse 
within ten days. Not many species are to be found in 
shady woods, but those species must be sought for there. 
To preserve flies in the cabinet from their insect enemies, 
I use naphthaline. The head of ordinary pins, when 
heated red-hot, may be thrust into the common moth- 
balls sold by the druggists, which when thus mounted 
serve all purposes. 


TABLE OF FAMILIES. 

Flies of a leathery or horny structure, living parasitically upon 
warm-blooded vertebrates in the adult condition, the larvae born 
when nearly ready to pupate; often wingless or with vestigial 
wings. .......... 65 

Fiies of a softer structure, not ectoparasites upon warm-blooded 
vertebrates, rarely viviparous. ...... 2 

Anal cell rarely narrowed in the border of the wing; antennae usu- 
ally composed of from eight to sixteen joints and more or 
less freely articulated with each other, usually longer than the 
thorax; not with a differentiated style or bristle;* palpi as a 
rule with four or five joints; discal cell usually absent. . 3 

Anal cell, if present, closed, or much narrowed in the border of the 
wing; discal cell almost always present; palpi never with more 
than two joints; antennae usually composed of three joints with 
a differentiated style or bristle. ..... 14 

ORTHORRHAPHA. 

A. NEMOCERA. 

Anal cell rarely (some Bibionidce, etc.] narrowed in the margin, 
if present; discal cell present only in many Tipulidce and the Rhy- 
phidcc; second longitudinal vein often furcate , the third very rarely 
if ever; palpi usually more or less elongate, composed of from one to 
five, usually four joints, rarely absent; antennce usually elongate 
and verticillate, generally filiform, rarely pectinate, composed of from 
six to thirty-nine joints, usually from eight to sixteen, the joints of 
the flagellum homomorphic and usually freely articulated with each 
other, a style or arista very rarely differentiated.- For the most 
part slender, delicate flies. 

3. Mesonotutn with a complete, V-shaped suture (incompletely V- 
shaped and sinuous in the Ptychopterinae) . Wings many-veined, 
often with a complete di>cal cell; ocelli very rarely present; 
both sexes dichoptic. For the most part large, always slender, 
flies with long legs; never very small. Daddy-longlegs, craneflies. 

Tipulidse, Si. 

* Chionea, a wingless tipulid, has the third antennal joint ending in 
a slender, three-jointed style; the flagellum of the Orphnephilidae is 
aristiform. 

(8) 65 


66 NORTH AMERICAN DIPTERA. 

Mesonotum never with a complete V-shaped suture, rarely with any 
distinct suture. For the most part small or very small flies. 4 

4. A complete discal cell present; antennae twelve-sixteen jointed; 

empodia developed pulvilliform, the pulvilli absent. 

Rhyphidse, 157. 
No discal cell. ......... 5 

5. Antennae composed apparently of two joints and a terminal arista, 

formed by nine or ten closely united segments; second basal 

cell present and small. Rare, small flies. Orphnephilidae, 153. 

Not such flies. ......... 6 

6. Wings with only a few longitudinal veins and no apparent cross- 

veins, almost always hairy; antennae slender, usually twelve 
to sixteen-jointed; coxae not elongate; tibiae without terminal 
spurs; legs not thickened; ocelli present or absent. Small or 
minute, delicate, mostly gall producing flies. 

Cecidoinyidae, 117 
Not such flies. ...... ... 7 

7. Ocelli present.* ......... 12 

No ocelli. .......... 8 

8. The marginal vein is not continuous beyond the tip of the wing. 9 
The marginal vein encompasses the wing; second and fourth long- 
itudinal veins furcate; many veined. . . . . 10 

9. Antennae slender; the joints more or less constricted, and often 

bushy plumose in the male; legs slender, the femora sometimes 
thickened; abdomen slender, wings usually narrow; no sexual 
holopticism. For the most part slender, delicate gnats; some 
small forms blood-sucking ('punkies'.) Chironomidae, no 
Antennae always shorter than the thorax, composed of ten or 
eleven closely united segments, and never plumose; legs strong, 
the hind pair more or less dilated; body thick-set, the abdomen 
ovate; anterior veins of wings stout, the posterior ones weak 
(compare certain Bibionidae when in doubt as to the ocelli); 
males holoptic. Small or minute, blood-sucking flies; black 
flies, buffalo gnats, turkey gnats. . . Simuliidse, 144 

10. Wings ovate or pointed, with numerous longitudinal veins, and 
without apparent cross-veins; veins very hairy; tibiae without 

* The presence or absence of ocelli is not a family character; a few 
forms among both the Mycetophilidae and Bibionidae appear to lack 
them. 


TABLE OF FAMILIES. 


67 


ter:ninil spurs. Small or minute, moth-like flies, the wings 
when at rest folded roof-shaped; rarely (Phlebotomus) blood- 
sucking Psychodidse, 92. 

Anterior cross-vein near middle of wing, distinct; second basal 
cell large and distinct; wings not folded roof-like when at 
rest. . . . . . . . . . . . ii 

11. Wings tomentose; fringed on the hind margin; antennae of male 

usually bushy plumose; the second and third veins separate at 
an acute angle. For the most part blood-sucking flies; mos- 
quitoes Culicidse, 96 

Wings bare; the third vein arises from the second near the middle 
of the wing, apparently continuous, the second vein arching 
suddenly forward; never blood-sucking in habit. Dixidse, 94 

12. Wings with a spider-web-like secondary venation. 

Blepharoceridse, 148 
Wings not with such secondary venation. .... 13 

13. Coxae much elongate (moderately so in the Sciarinae) ; antennae 

usually elongate, the joints usually with constrictions between 
them; three or two ocelli present; in the latter case one situated 
near each eye and sometimes perceptible with difficulty; rarely 
the ocelli appear to be entirely absent; no sexual holopticism; 
all the tibiae spurred; second basal cell never complete. 

Mycetophilidae , 131 

Coxae short; the thorax not strongly arched above; antennae usu- 
ally shorter than the thorax and closely jointed without marked 
constrictions, sometimes 14-16 jointed, longer and slender; legs 
usually strong, the pulvilli usually present (Bibioninae) ; eyes 
of male often large and holoptic; second basal cell often com- 
plete. ... ... Bibionidae , 140 

AA. BRACHYCERA. 

Anal cell closed before the border of the wing or distinctly narrowed 
in the border; if absent or very short the antenncc are composed of 
two or three simple joints with or without a style or arista. Palpi 
rarely elongated, never with more than one freely articulated joint, 
that is tivo-jointed or one-jointed or absent. Antennce: (a) elongate, 
composed of distinctly separable joints, the joints of the flagellum ho- 
momorphous and sometimes as many as thirty in number; (b) com- 
posed of not more than ten closely united joints w'ithout style; (c) 
the so-called third joint is complex, that is, composed of from four 
to eight segments or annuli, I he distal one or ones usually differ- 


68 NORTH AMERICAN DIPTERA. 

entiated into a style or arista; (decomposed of three simple joints 
(sometimes apparently two}, with or without a differentiated, one to 
three-jointed, style or arista. Second vein of the wing never furcate, 
the third often; discal cell almost always present. 

14. Antennae composed of two or three simple joints, the distal one 

not annulated nor segmentated, usually with a one to three- 
jointed terminal or dorsal arista or terminal style (cl) , . 18 
Antennae of the structure of (a), (b) , or (c). . . . 15 

15. Empodia undeveloped or bristle-like; antennae elongate, the fla- 

gellum composed of two or three joints, without apparent style; 
front concave between the eyes in both sexes. ... 25 
Empodia developed pulvilliform; flagellum of antennae with nu- 
merous, distinct joints, or forming the complex, so-called third 
joint, with or without a differentiated style or bristle; body not 
bristly. .......... 16 

B. Antenna; composed of more than five joints, or the third-joint 
complex, four to eight segmented, inclusive of style or arista zchen 
present: 

16. Squamae rather large; third longitudinal vein furcate; five poste- 

rior cells always present; the costal vein encompasses the wing; 
flagellum composed of from four to eight segments, never with 
style or arista; males holoptic; proboscis of female adapted for 
piercing. Horseflies, gadflies, greenheaded flies. 

Tabanidge, 176 

Squamae small or vestigial; for the most part flower flies; males 
usually holoptic. . . . . . . . . 17 

17. Tibiae without spurs; wing veins not crowded anteriorly; third 

antennal joint composed of seven annuli with a terminal slender 
style or arista; two submarginal, five posterior cells always pres- 
ent, the fourth closed. Very large, robust, southern flies. 

Acanthomeridae, 173 

Tibiae almost invariably without spurs; longitudinal veins of the 
wings usually more or less crowded anteriorly, the posterior 
ones often weak; the costal vein does not reach beyond the tip 
of the wing; scutellum often with spines; third vein almost al- 
ways furcate; four or five posterior cells, the fourth rarely or 
never closed; antennae long or short (b) , (c). 

Stratiomyidse, 164 

The middle tibiae, at least, with distinct spurs; the costal vein en- 


TABLE OF FAMILIES. 69 

compasses the wing; third vein always furcate; five posterior 
cells present, the posterior veins not evanescent; antennae (a) , 
(b), (c). . , Leptidae, pt. 157 

BB. Third joint of 'antenna simple, not composed of annul i, with 
or without a differentiated style or arista. 

18. Antennae apparently two-jointed, with a three-jointed arista; wings 

(rarely wanting) with several stout veins anteriorly and other, 
weaker ones apparently connected with them and running ob- 
liquely across the wing. Femora flattened, the hind ones elon- 
gated; antennas situated low down. Small, hunchbacked, quick 

running, bristly flies Phoridae, 236 

Not such flies, the antennae almost invariably with three easily 
distinguishable joints. .... 19 

19. Empodia developed pulvilliform, that is three nearly equal, mem- 

branous appendages on the under side of the claws. 20 

Empodia wanting, vestigial or linear, not developed like the pul- 

villi 22 

20. Squamae very large; thorax and abdomen inflated; head small, 

eyes relatively large; antennae and venation variable. 

Cyrtidae, 182 
Squamae of moderate size, or small. .... 21 

21. Middle tibiae at least with spurs; no bristles on femora or tibiae; 

third vein furcate; five posterior cells present (four sometimes 
in Dialysis and iMisgomyia}; anterior cross-vein always dis- 
tinct; third joint of antennae with a bristle or slender style, 
usually terminal. Leptidae, pt. 157 

Venation intricate, the third and fourth veins often coalescent for 
a short distance; tibiae without spurs; antennae with a slender, 
three-joiuted style; usually hairy. . Nemestrinidae, 186 

22. Third longitudinal vein furcate; two or more submarginal cells 

present. .... 23 

Third vein not furcate, but one submarginal cell. . . 31 

23. Arista or style of antennae always terminal when present. 24 
Arista dorsal Empididae, pt. 218 

24. Front distinctly hollowed out between the eyes; eyes of males 

never contiguous; basal cells large; mostly large flies. . 25 
Front plane or convex; males often holoptic. , . 26 

25. Proboscis with fleshy labella at tip; venation complicated, the 

fourth vein curves forward to terminate before the tip of the 


NORTH AMERICAN DIPTERA. 

wing; palpi small or wanting. Large to very large, bristleless 
flies Mydaidae, 190 

Proboscis without fleshy labella at tip, horny and rigid; five pos- 
terior cells almost always present; palpi usually prominent. 
Mostly large, bristly, predaceous flies. . AsilidaB, 192 

26. Five posterior cells in the wing; basal cells large. . . 27 
Not more than four posterior cells.* ..... 29 

27. Venation intricate; empodia and pulvilli membranous, biit fre- 

quently minute (see 21).. 
Venation not intricate, the anterior cross-vein always apparent. 28 

28. The fourth vein terminates before tip of wing; male sexual organs 

prominent; males dichoptic. . . . Apioceridae , 188 
The fourth vein terminates beyond the tip of the wing; male sex- 
ual organs small; males often holoptic. . There vidae, 205 

29. Third antennal joint without bristle or style; three posterior cells, 

the first narrowed or closed; the fourth vein terminating at or 

before the tip of the wing. . . . Scenopinidae, 208 

Third antennal joint usually with a terminal style; four or three 

posterior cells; the fourth vein terminates beyond tip of wing. 30 

30. Anal cell narrowly open or closed near border of wing (if discal 

cell wanting, see Hilarimorpha p. 157, footnote) . 

Bombyliidae, 210 

Anal cell closed remote from border, sometimes absent; discal cell 
not rarely absent. ..... Empididae, 218 

31. Wings pointed; no cross-veins, save at base; second basal cell 

short; arista terminal; small flies. . Lonchopteridae, 240 
Wings not lanceolate. ........ 32 

32. Anal cell elongate, acute, closed toward or near the border of the 

wing; second basal cell usually long. .... 36 
Anal cell, if present, short, closed remote from the border of the 
wing, not acutely produced (rarely produced in a narrow, lobe- 
like prolongation.) ........ 33 

33. Second basal cell confluent with discal cell, or the discal cell ab- 

sent; auxiliary vein usually vestigial or indistinct; anal cell 
often absent; usually small flies. ..... 34 

Second basal cell separated by a cross-vein from a complete discal 
cell; auxiliary vein and anal cell usually complete. . 40 

* Five in a very few species of Rombyliidse. 


TABLE OF FAMILIES. 71 

34. For the most part brilliantly colored, predaceous flies; face of male 

usually narrower than that of female; arista dorsal or terminal; 
hypopygium often enlarged or conspicuous. 

Dolichopodidae, 228 
Not brilliantly colored, predaceous flies 35 

35. Eyes sometimes contiguous; head small, the proboscis usually 

rigid; arista usually terminal. . . Empididse, pt. 218 

Eyes never contiguoiis; proboscis not rigid; arista almost always 

dorsal. ........ 4 2 

CYCLORRHAPHA. 

A frontal lunnle above the base of the antenna-; third antennal joint 
always simple, not annulated or complex, with a terminal or dorsal 
arista, rarely with a terminal style; third vein never furcate; never 
more than three complete posterior cells present. Empodia never pul- 
villiform. 

36. Between the third and fourth longitudinal veins and subparallel 

with them a spurious longitudinal vein; or, when rarely absent, 
the first posterior cell is closed remote from the border; first 
posterior cell always closed; head never with bristles, which are 
rarely present elsewhere; males usually holoptic; almost always 
with a dorsal arista, rarely a terminal style. Usually brightly 

colored flower flies Syrphidae, 246 

No spurious longitudinal vein. ...... 37 

37. Front broad in both sexes; antennae with a terminal style or dor- 

sal arista; face usually with grooves below the antennae; probos- 
cis elongate and slender, often folding; no bristles anywhere 
(Conopidcc, 261.) 
Not such flies; bristles almost invariably present. . . 38 

38. Hind metatarsi enlarged and ornamented, especially in the males, 

males holoptic; arista terminal. . . Platypezidae, 241 
Hind metatarsi not enlarged nor ornamented. 39 

39. Head large, composed chiefly of the eyes, the front in the males 

narrowed or the eyes contiguous; first posterior cell narrowed; 
arista dorsal; rather small flies. . . Pipunculidse, 244 
Head not large, subspherical, the front broad in both sexes, pro- 
boscis short, not rigid; first posterior cell narrowed; legs elon- 
gated (Micropezidcc pt. 264) . 

Head small, the front narrowed or eyes contiguous in male; first 
posterior cell wide open (Empididfg, pt. 218). 


y 2 NORTH AMERICAN DIPTKRA. 

40. Head small; proboscis more or less elongated; alula of wings usu- 

ally vestigial (jEmpididte, pt. 218). 

Head not unusually small; proboscis rarely elongated; arista al- 
most invariably dorsal. . . . . . . . 41 

A. MYODARIA. 

Never more than three posterior cells present, the first of which only may be 
closed or narrowed in the margin ; none of the longitudinal reins furcate ; 
marginal and submarginal cells never closed; anal cell very rarely produced 
toward the margin of the icing (Micropezidce pt. Ortalididie, pt. etc.) Antennae 
three-jointed, simple, with a bare, pubescent, pectinate or plumose arista, which 
is almost always dorsal in position, never thickened into a terminal style. More 
or less bristly Jlies. 

41. Squamae large; front of male narrowed or eyes contiguous. 59 
Squamae small; eyes of male not more approximated than those of 

female, or if so the narrowing is due to the diminished width of 
the median stripe, the borders remaining the same, the males 
never holoptic; posterior callus of thorax almost always not dis- 
tinct. .42 

B. ACALYPTERJZ. 

Squamae always small or vestigial. Auxiliary vein often indistinct or vestigial, 
or closely approximated or fused with the first vein. First longitudinal vein 
shortened, often very short. Basal cells small, the posterior ones often indistinct 
or wanting. Males never holoptic, the front in this sex never markedly narrowed. 
Thorax without complete transverse suture; posterior callosity usually absent. 
Never large flies, usually small or very small. 

42. Auxiliary vein present, separated from first longitudinal vein and 

terminating distinctly in the costa; the first vein usually ends 
near or beyond the middle of the wing; posterior basal cells 
present. .......... 43 

Auxiliary vein absent, vestigial or incomplete; the first vein usu- 
ally ends in the costa before the middle of the wing. . 49 

43. A distinct bristle on each side of the face near the oral margin, i. 

e. oral vibrissae present. ....... 44 

No oral vibrissae. ......... 45 

44. Mesonotum and scutellum flat; front bristly; cheeks and face bris- 

tly; all the tibiae spurred and with preapical bristle; seashore 

flies Phycodromidse, 317 

Mesonotum not flattened, convex; no costal spine; more than 
four abdominal segments visible. . Cordyluridae, 327 


TABLE OF FAMILIES. 


73 


Wings elongate, the cross-veins often approximated; post-vertical 
bristles divergent; front bristly; smaller, somewhat elongate 
flies; sixth and first veins short. . Heteroneurid&e, 318 

Front never bristly near the antennae; abdomen somewhat elon- 
gate, cylindrical, usually narrowed near base. Small, black 
flies about decaying matter. .... Sepsidae, 269 

Costa almost always pectinate; tibiae with spurs and preapical 
bristles; not very small flies. . . Helomyzidae, 324 

45. Femora thickened; hind tibiae usually dilated; basal cells not very 

small; first posterior cell narrowed; all the tibiae with preapical 
bristle. Moderate sized, bare, southern flies. 

Rhopalomeridse, 280 
Not such flies. ......... 46 

46. First posterior cell closed or narrowed in the margin; abdomen 

elongate; legs long or very long. . . , . . 47 

Not such flies. ......... 48 

47. Eyes large, the cheeks and posterior orbits narrow 7 , the occiput 

concave: 

Proboscis short; ovipositor not elongate. Tanypezidse, 264 
Proboscis greatly elongate and folding near its middle; ovipos- 
itor very long Conopidse, pt. 261 

Head subspherical, the cheeks broad and face retreating; probos- 
cis short. ...... Micropezidse, 264 

48. One or two fronto-orbital bristles; preapical bristle absent or pres- 

ent; wrings sometimes pictured; anal cell always rounded distally. 

Sapromyzidse, 288 

Upper fronto-orbital bristles, only, present; ovipositor horny, more 
or less elongate; anal cell often acute distally, or drawn out 
into a narrow, acute lobe; arista seldom plumose; no preapical 
bristle (except Automola) ; wings almost invariably pictured. 

Ortalididse, 272 

Fronto-orbital bristles present* or absent; second joint of antennae 
often elongated; postvertical bristles divergent; a preapical 
bristle; ovipositor not horny; wings often pictured. Meadow 
flies, ....... Sciomyzidae, 321 

49. Head produced on each side into a lateral process for the eye; 

basal cell confluent with discal cell. . . Diopsidse, 314 
Head not produced into lateral processes. . . . . 50 

* If small, greenish black flies of the sea-coast, with globular third 
antennal joint, compare Canace (Ephj-dridae). 
9 


74 


NORTH AMERICAN DIPTERA. 


50. Hind metatarsi incrassate and usually shorter than the second 

joint; oral vibrissae present; second basal cell distinct or not; 
about excrement or near water. . . Borboridas, 315 

Hind metatarsi not incrassate and always longer than the follow- 
ing joint. .......... 51 

51. Discal and basal cells united, the separating cross-vein vestigial 

or absent. .......... 52 

Discal and second basal cells separated. .... 54 

52. Anal cell absent. ......... 53 

Anal cell complete, though often small. .... 54 

53. Front bare, or at the most bristly above; small, usually light color- 

ed flies Oscinidae, 310 

Front often bristly; mouth cavity usually large; no oral vibrissae; 
rather small to very small black or dark -colored flies about water. 

Ephydridse, 303 

54. Scutellum elongate, triangular; with spines or protuberances on 

its margin; femora thickened. . Rhopalomeridae, 280 
Flies not having all the above characters. .... 55 

55. Oral vibrissae present. ........ 56 

No oral vibrissae. ......... 58 

56. Arista long plumose, or pectinate above. Drosophilidae, 299 
Arista bare, pubescent or short plumose. .... 57 

57. Front bare or bristly at vertex only; small, black flies, with nar- 

row, usually contracted abdomen. . . Sepsidse, 269 

Front bristly at least as far as the middle; often light colored, small 
or very small flies. Agromyzidse, 291; Geomyzidse, 297 

58. The auxiliary vein is evanescent at its tip, where it turns sharply 

forward at some distance before the tip of the first vein; wings 
almost always pictured; anal cell angular, or drawn out into 
a narrow acute lobe; no preapical tibial bristle. 

Trypetidse, 282 

Auxiliary vein more or less fused with the first vein; antennae 
more or less elongate and decumbent; anal cell not produced; 
rather small, elongate flies. Psilidse, 267 

Posterior basal and anal cells very small; wings rarely pictured. 
Small or very small, often silvery gray or whitish gray species. 

Geomyzidse, 297 


TABLE OF FAMILIES. 


75 


BE- CALYPTER.K. 

Squain<z well developed or of moderate size, not vestigial. Aux- 
iliary vein alicays distinct in its whole course; first longitudinal 
vein never very short, usually of considerable length. Males often 
holoptic, or the front in that se.\- narrowed. Thorax with complete 
transverse suture; posterior callosity present. Usually flies of mod- 
erate or considerable size, never very small. 


59. Oral opening small, the mcmthparts small or vestigial; first poste- 

rior cell closed or narrowed (except Gastrophilus] . Bot flies. 

Oestridae, 344 
Oral opening of usual size, the mouth parts not vestigial. 60 

60. Hypopleurae with a tuft of bristles; first posterior cell narrowed or 

closed. .......... 61 

Hypopleurae not with tuft of bristles; first posterior cell narrowed 
or fully open in the margin. ... 64 

61. Antennal bristle bare or somewhat pubescent. Tachinidse, 358 
Antennal arista plumose or very distinctly pubescent. . 62 

62. Arista bare on the distal half; dorsimi of abdomen rarely bristly 

on anterior part. . . . Sarcophagidge, 348 

Arista plumose or distinctly pubescent to tip. ... 63 

63. Dorsum of abdomen usually bristly on anterior part; legs usually 

long. . . Dexiidse, 352 

Abdominal segments without bristles, save more or less near the 

tip; legs not noticeably elongated (Calliphorinae) . Muscidse, 337 

64. First posterior cell narrowed or closed; arista plumose to tip. 

Muscidse, pt. 337 

First posterior cell very slightly or not at all narrowed in the 
margin; arista plumose, pubescent or bare. Anthomyidse, 331 

AA. PUPIPARA. 

65. Wingless flies, parasitic upon bats; head folding back on the dor- 

sum of the thorax. .... Nycteribiidae, 386 

Winged or wingless flies, parasitic upon birds or mammals; head 

not folding back upon dorsum or thorax. . . 66 

66. Antennas reduced; wings with distinct parallel veins and outer 

cross-veins when present; claws simple; palpi leaf-like, project- 
ing in front of the head; almost exclusively parasitic upon bats. 

Streblidse, 384 

Antennae usually more elongate, the joints more or less distinctly 
separated; head sunk into an emargination of the thorax; wings, 
when present, with veins more or less crowded anteriorly, the 
weaker ones running outward and backward, the cross-veins 
short and approximated to the base of the wing; claws large, 
bidentate or tridentate ; palpi not leaf-like nor protruding in 
Iront of the head. . . . Hippoboscidse, 382 


NORTH AMERICAN DIPTERA. 


MYODARIA. 

The very large group of flies, called here the Myodaria, 
after Desvoidy, and very commonly known in the past 
as the Muscidae, sens, lat, has been divided into many 
lesser groups by students of the order. The number and 
limitations of these groups are the subjects of most diver- 
gent opinions, no two writers agreeing. I have, in gen- 
eral, followed the opinions of L,oew and Schiner where 
I had none of my own, with some suggestions from 
Czerny and Hendel. In deference to common usage I 
give the family termination to the names of the groups 
adopted, not because I believe that they are of equivalent 
rank to the families, as generally accepted, of the Cyclor- 
rhapha, for I most emphatically do not, but because of 
common vogue. It really matters little what they are 
called, so long as it is distinctly remembered that they 
have in general less morphological significance. The 
only danger is that the ether families may be broken up 
into countless groups of equivalent rank, a result to be 
deplored and which would serve no useful purpose. 

The family, or superfamily, whatever it be, includes 
more than a half, perhaps, of all living diptera. They, 
and especially the Calypterse, are the dominant diptera 
of the present time, the latest and most highly special- 
ized types of the order. And it is because of this dom- 
inance that they are exceedingly hard to classify clearly 
and distinctly. Nor will their classification approach a 
much more satisfactory equilibrium until more of the 
world's fauna is known, especially in view of the fact 
that the smaller forms in particular have been, in gen- 
eral, largely neglected by competent students as the 
proletariat of the order. 


MYODARIA 


77 


That the group is a difficult one, even for the expert, 
is only too true. Full descriptions and figures are al- 
most indispensable in many, if not most cases for allay- 
ing doubt as to genera, especially in the present chaotic 
condition of the nomenclature of the Calypterae. I have 
used the more commonly employed distinctions for the 
'families' of the Calypterae, and there can be no question 
but that these, oftentimes trivial, characters do, for the 
most part, define natural groups, but not in all cases, 
and the student must find for himself the divergent, 
anomalous, or homoplastic forms. And, as a general 
rule in taxonomy, he should remember that differences 
are of more importance than resemblances in defining 
relations. That we shall discover more natural charac- 
ters for their definition soon is without doubt, but, until 
specialists come to some fairly general agreement as to 
what these characters are, we must continue to use those 
which bring together the great majority of the forms into 
genetic groups. 

Czerny and Hendel place much importance on the di- 
rection of the postvertical bristles in the arrangement of 
the Acalypterae, and I am disposed to admit the justice 
of their claim in large measure. According to these 
authors these bristles are convergent in the Helomyzidae, 
Sapromyzidae, Drosophilidae, Geomyzidae, Milichinae 
and Ochthiphilinae; erect in the Trypetidae; divergent 
in the Cordyluridae, Heteroneuridae, Ortalididae, Micro- 
pezidae, Sciomyzidae, Sepsidae and Lonchaeidae, as these 
authors accept these families. 

Upon the cruciate bristles of the front they also place 
not a little weight, as present more or less in the Antho- 
myidse, Heteroneuridae, Ephydridae, etc. It must be 
remembered, however, that all these bristles are usually 
minute, often exceedingly so; or absent in forms closely 
related otherwise to those having them well developed ; 


7 8 NORTH AMERICAN DIPTHRA. 

and they are often difficult of discernment. I am not 
disposed to place a large degree of reliance upon char- 
acters so inconstant. 

It will be observed that, as in the former edition, I fol- 
low Schiner in arranging the Myodaria in a reverse order 
from that usually given in systematic works and cata- 
logues. In the holoptic eyes, enlarged squamae, greater 
development of the bristles, entire absence of apical 
arista, and larger size, the Calypterae demonstrate their 
high rank among the Cyclorrhapha ; and they of course 
could not have been the ancestral type from which the 
Acalypterae arose. The Acalypterae are for the most 
part a divergent branch with certain decadent special- 
izations like those of the oligoneurous Nemocera. The 
relationships between the Tanypezidae or Micropezidae 
and certain forms which by common consent are placed 
among the Conopidae, are beyond all dispute; indeed in 
my opinion the Conopidae should be included among the 
Myodaria, as they w 7 ere by Desvoidy. 

PUPIPARA. 

The singular group of flies known as the Pupipara or 
Eproboscidea is composed wholly of ectoparasites infest- 
ing mammals, birds and other insects, living among the 
hair or feathers of their hosts and subsisting upon their 
juices. This parasitic habit has induced many remark- 
able modifications of structure, as would be supposed. 
The compound eyes are never large, and, in those flies 
living upon the crepuscular or nocturnal bats, they have 
become reduced to the merest vestiges. So, also, the 
ocelli are in general degenerate and often wanting. The 
antennae are short, the joints often apparently reduced 
in number, and they are often bristly. The mouth-parts, 
while still retaining all the constituent parts of most 
other cliptera, have become much abbreviated, and are not 


PUPIPARA. 


79 


at all retractile. The body is more or less flat, the abdo- 
men indistinctly segmentated in most cases and leathery 
in appearance. The legs are always stout, sometimes 
much elongated, with strong and stout claws, which may 
have an strong pectination in addition to the enlarged 
basal part. In their breeding habits all are believed to 
be pupiparons, that is giving birth, not to eggs or even 
young larvae, as is the case with nearly all other diptera, 
but to larvae just ready to transform into puparia, an 
evident adaptation to their peculiar enviromental condi- 
tions. The wings, as would be supposed, are often ves- 
tigial or wanting, and in many cases the venation has 
undergone degeneration. But a single form is known to 
be parasitic upon other insects, bees, of a family hitherto 
unknown to occur in America. 

Because of these marked and peculiar habits, and the 
structural characters, some recent writers are inclined to 
raise the rank of the group to a subordinal value, making 

it equivalent to all the other diptera combined. To this, 
however, I am decidedly opposed. The flies seem, with 
hardly a doubt, to be merely degenerate descendants of 
the Muscids, and probably of the acalyterate division. 
The venation of such forms as Raymondia is characteris- 
tically acalypterate ; in some others there has been, ap- 
parently, an elongation of the first and sixth veins, and 
an enlargement of the basal cells. Schiner long ago 
described a peculiar type with reduced wings, parasitic 
upon hawks, which he placed among the acalypterates 
in the vicinity of the Borboridae, and it does not seem un- 
likely that this is the real relationship of the whole group. 
Very similar structural adaptations are observed among 
the parasitic and wholly unrelated Phoridae bristly, re- 
duced antennae, loss of eyes and wings, leathery abdomen, 
stout legs, etc.; or among the tsetse flies distinctly pu- 
piparous habits. The most that I am willing to concede 
to the Pupipara is a rank equivalent to that of the Myoda- 
na. The group is a comparatively recent one geological- 
ly, in all probability. 


1, Pedicia; 2, Atarba pleuralis; 3, Rhipidia costalis; 4, Ctenophora; 5, Epi- 
phragma sackeni; 6, Bittacomorpha clavipes; 7, Pachyrhina; 8, 9, Desruatomyia 
anomala (type); 10, Aldrichia ehrmanni; 11, Dolichomyia yracilis (type); 12, 
13, Nephrocerus (Penna. ); 14, Ischnomyia; 15, Pallojrfera jucundn; 16, Chtsia; 
17, 18, Heterocheila; W, Eclimis: 20, 21, Lr]n'do/>lior<i retusta. 


I. FAMILY 


Helobia hybrida, enlarged. After Washburn. 


Large to moderately small, slender flies, with long, 
slender legs. Head subspherical ; occiput strongly de- 
veloped; face often produced snout-like. Eyes round, 
separated by the broad front; sometimes approximated 
above and below the antennae, but never contiguous. 
Ocelli almost always ( Ti ichocera) wanting. Antennae 
rarely shorter, usually longer than the head and thorax 
together; bead or thread-like, composed of from six 
( Amsomera) to thirty-nine ( Cerozodia* ) joints, the joints 
of the flagellum never plumose, but usually with more 
or less conspicuous bristly hairs; the joints sometimes 
serrated or pectinated; usually there are eleven, twelve 
or fourteen joints in the flagellum. Proboscis more or 
less projecting, in a few genera very much elongated; 
palpi four or five jointed, the terminal joint often elon- 

' This genus, from Australia, has, according to Osten Sack en, from 
twenty-nine to thirty-seven joints in the flagellum, all of which, ex- 
cept the terminal one or ones, are branched. 

(10) Si 


82 NORTH AMERICAN DIPTERA. 

gated, whiplash-like. Thorax convex above, with a very 
distinct suture in the form of a shallow V, except in the 
Ptychopterinse ; prothorax usually distinct, collar-like; 
scutellum half-round; metanotum strongly developed. 
Abdomen cylindrical, composed of seven or eight joints; 
genitalia prominent, in the male very variable in struc- 
ture ; in the female, the ovipositor (save rarely) has two 
pairs of long, horny, pointed valves. Legs very long 
and slender; the tibiae sometimes with terminal spurs. 


Fig. 24. Venation. 

Wings long, but comparatively narrow; in rest spread 
apart or lying parallel over the abdomen ; auxiliary vein 
present; always six longitudinal veins; usually a com- 
plete discal cell; both basal cells long; the anal cell 
usually widely open; seventh vein usually distinct (save 
in the Ptychopterinae) and of variable form; axillary 
lobe rounded, rarely angular. 

The family Tipulidse comprises the largest of the 
nematocerous flies, some of which exceed two inches in 
length. The abdomen is always elongate. The legs are 
very long and delicate so delicate indeed that one sel- 
dom succeeds in capturing the insects without the loss 
of one or more. Flies of this description with a distinctly 
impressed V-shaped 'suture' on the mesonotum will be 
immediately recognized as belonging to this family. The 
females differ from those of most other flies in having the 
ovipositor adapted for the deposition of their eggs in the 
ground or other firm substances. When the weather is 


favorable the eggs hatch in a little more than a week. 
The larvae are ash-gray or brownish in color, more or 
less transparent, composed of twelve segments. The 
head is incompletely differentiated and retractile, and has 
the maxillae and mandibles more or less horny and stout; 
there are short fleshy antennae in most larvae, but are 
long and two-jointed in the Tipulinae. The organs of 
locomotion generally consist of transverse swellings on 
the under side of the body, provided with very minute, 
stiff bristles. The anal end of the body is truncate, with 
a single pair of spiracles; and the margins of the trunca- 
ture are for the most part provided with fleshy, retractile 
processes of variable size and shape. Some aquatic lar- 
vae have a long tube at the end of the body, which serves 
for respiration when raised to the surface of the water. 

Most of the larvae live in the earth or in soil-like, de- 
composing wood, in fungi, or in water. Others live on 
the leaves of plants and are like caterpillars in appear- 
ance, the resemblance to which is yet more heightened 
by the green color, with a crest of tubercles on the back. 

The pupae, like those of many of the members of this 
suborder, are free. The thorax has two horn-like pro- 
cesses which represent the thoracic spiracles, one of 
which may acquire a very great length for the purpose 
of breathing from the surface while under water. The 
abdominal segments have transverse row r s of hairs, bris- 
tles or spines, which enable the pupa to escape from its 
place of concealment when about to complete its meta- 
morphosis. 

The adult flies are often seen in the late summer and 
autumn. They will be most usually met with in mead- 
ow-lands and forests, flying awkwardly for a few steps, 
close to the ground till they become entangled in the 
grass or twigs, and then extricating themselves, rising 
again to repeat the same aimless, clumsy flight. 


8 4 


NORTH AMERICAN DIPTERA. 


22 


Fig. 25. Tipulidae. i, Limophila luteipennis; 2, Dicranota riv- 
ularis; 3, Plectromyia modesta; 4, Amalopis calcar; 5, Trichocera 
bimacula; 6, Cryptolabis parado.ra; 7, Goniomyia sulphurella; 8, 


TIPUIvIM. 


Fig. 26. Tipnlidae. 23, Elliptera, sp. ; 24, Diotrepha mirabilis; 
25, Rlnpidia snbpectinata; 26, Mongowa pallida; 27, Tipula subin- 
fnscata; 28, Polymera albitarsis; 29, Geranomyia pallida; 30, 7>//- 
cholabis complexa; 31, Rhamphidia albitarsis; 32, Atarba pleuralis. 

The name of 'daddy-long-legs' is the one usually 
applied to members of this family in England, but in 
America this term is generally used to designate the 
Phalangidse or harvest spiders. The name 'crane-flies' 
is preferable. Commonly they are harmless, but some 
of the species in the larval state are very destructive, 
feeding upon the tender rootlets of grass and grain, and 
causing the plants over large surfaces to wither and die. 
There are about twelve hundred species known. 

Trimicra pilipes; 9, Limnophila quac(rata; 10, Gnophomyia tristis- 
sima; n. Rhypholophus rubellus; 12, Bittacomorpha clavipes; 13, 
Anisomera neglecta; 14, Rhaphidolabis tenuipes; 15, Orimarga al- 
piua; 16, Dicranomyia heretica; 17, Dicranomyia longipennis; 18, 
Toxorhina tnagna; 19, Limnophila areolata; 20, Erioptera, sp. ; 
zitHelobiapunctipennis; 22, Antocha opalizans. After Osten Sacken. 


86 NORTH AMERICAN DIPTERA. 

In this family are placed several wingless forms, or 
those with the wings more or less rudimentary. One of 
the former is Chionea, the species of which are found on 
snow, often in the coldest weather. 

The family Tipulidae is easily divided into three sub- 
families, which I prefer to call the Ptychopterinse, Ivim- 
nobiinse and Tipulinse, and which correspond precisely 
with the Ptychopterina, Tipulidae brevipalpi and Tipu- 
lidae longipalpi of Osten Sacken. 

The following table is chiefly based upon that of Osten 
Sacken in his monograph, which will be indispensable to 
the student. The nomenclature of the venation is that 
of Osten Sacken. 

TABLE OF GENERA. 

1. Seventh longitudinal vein present, that is there are two longitud- 

inal veins between the fifth vein and the posterior margin of the 
wing. ........... 2 

Seventh longitudinal vein absent; no distinct V-shaped suture on 
mesonotum. ...... Ptychopterinse. 

2. Last joint of the palpi shorter or not much longer than the two pre- 

ceding together; the auxiliary vein usually ends in the costa and 
is connected with the first longitudinal vein by a distinct cross- 
vein; antennae six to sixteen jointed, rarely more. Limnobiinse 
Last joint of the palpi whiplash-like, much longer than the three 
preceding together; antennas rarely with more than thirteen 
joints; the auxiliary vein ends in the first longitudinal vein by 
an abrupt curvature at the tip, not connected with the first vein 
by a cross- vein ........ Tipulinse. 


1. Wingless, spider-like in appearance. . . . Chionea. 
Winged. ........... 2 

2. A single submarginal cell present. ...... 3 

Two submarginal cells present (one in Goniomyia manca.} . 5 

3. Antennae i4-jointed. ...... Limnobiini. 

Antennae i6-jointed. ........ 4 


TIPULIDJE. 

4. Tibiae with spurs at the tip; the first longitudinal vein usually ends 

in the second. ...... Cylindrotomini. 

Tibiae without spurs; the first vein ends in the costa. Antochiiii. 

5. Tibiae without spurs at the tip. .... Eriopterini. 
Tibiae with spurs at the tip. ....... 6 

6. The subcostal cross-vein is beyond the origin of the second longi- 

tudinal vein. ......... 7 

The subcostal cross-vein is before the origin of the second longi- 
tudinal vein. ....... Amalopim. 

7. Antennae composed of sixteen joints. . . Limnophilini. 
Antennae composed of from six to ten joints, often much elongated. 

Anisomerini. 

LIMNOBIINI. 

1. Proboscis longer than the head and thorax together (29). 

Geranomyia. 
Proboscis shorter than the head and thorax together. . . 2 

2. Antennae pectinate or subpectinate, at least, in the male (25, p. 80. 3) 

Rhipidia. 
Antennae not pectinate. ........ 3 

3. A supernumerary cross-vein between the sixth and seventh veins. 

Discobola. 
No cross-vein connecting the sixth and seventh veins. . . 4 

4. Tip of the auxiliary vein usually opposite, or before, or only a short 

distance beyond the origin of the second vein; marginal cross- 
vein always at the tip of the first longitudinal vein; legs slender. 

Dicranomyia. 

Tip of the auxiliary vein usually far beyond the origin of the second 
vein; marginal cross-vein sometimes at the tip but often some 
distance before the tip of the first vein; legs comparatively stout. 

Limnobia. 

ANTOCHINI. 

1. Rostrum at least as long as the head, sometimes very long; no mar- 

ginal cross-vein. ......... 2 

Rostrum shorter than the head. ...... 4 

2. W T ings without submarginal cell (18) .... Toxorhina. 
Wings with submarginal cell. ....... 3 

3. Rostrum not much longer than the head (31). Rhamphidia. 
Rostrum the length of the body. . . . Elephantomyia. 


88 NORTH AMERICAN DIPTERA. 

4. Discal cell open. ......... 5 

Discal cell closed. ......... 7 

5. Second basal cell considerably shorter than the first. . . 6 
vSecond basal cell of about the same length as the first (23). 

Elliptera. 

6. Three posterior cells; the great cross-vein more proximal than the 

origin of the second vein (24). . . . Diotrepha. 

Four posterior cells; the great cross-vein more distant than the 

origin of the second vein, .... Orimarga. 

7. No marginal cross-vein whatever (32, p. So, 2). . . Atarba. 
Marginal cross-vein present. ...... 8 

8. The first longitudinal vein ends in the costa nearly opposite the 

inner end of the submarginal cell. ..... 9 

The first vein ends in the costa far beyond the inner end of the 
submarginal cell. ..... Dicranoptyclia. 

9. Submarginal cell as long or but little longer than the first posterior 

cell (3O) Teucholabis. 

Submarginal cell much longer than the first posterior cell (22) . 

Antocha. 
KRIOPTERINI. 

1. Five posterior cells; male antennae not peculiar. . Cladura. 
Five posterior cells; joints of the male flagelhini binodose, form- 
ing apparently twenty-eight joints in the antennae (25 also fig. 
5, 1, page 27, 9). . . . Polymera. 

Four posterior cells. ........ 2 

2. The, inner marginal cell has almost the shape of an equilateral tri- 

angle (6) Cryptolabis. 

Inner marginal cell of the usual shape. .... 3 

3. Wings conspicuously hairy on the whole surface or along the 

veins. ........... 4 

Wings not conspicuously hairy, veins bare or nearly so. . 7 

4. Antennal joints subreniform and nodose; eyes nearly contiguous 

above and below. Sigrnatomera. 

Species not having the foregoing characters. ... 5 

5. Wings hairy on the whole surface (11). . Rhypholophus. 
Wings hairy along the veins only. ...... 6 

6. Second submarginal cell longer than the first (2O) . Erioptera. 
First submarginal cell longer than the second. Molophilus- 


89 

7. First submarginal cell short, not more than half the length of the 

second. ... ...... 8 

First submarginal cell more than half the length of the second, n 

8. Marginal cross-vein present. ....... 9 

Marginal cross-vein absent (7) Goniomyia. 

9. Second submarginal cell in contact with the discal cell, the ante- 

rior cross-vein obsolete. . . . . . . .10 

Anterior cross-vein present, the first posterior cell intervening be- 
tween the submarginal and the discal cells. . Empeda. 

10. Seventh longitudinal vein very short; no empodia (26). 

Mongoma. 

Seventh longitudinal vein not unusually short; empodia present. 

Paratropesa. 

u. Seventh longitudinal vein conspicuously bisinuate (21). Helobia. 
Seventh longitudinal vein straight. . . . . . 12 

12. Length of the auxiliary vein beyond the cross-vein at least twice 
that of the posterior or great cross-vein (8) . . Trimicra. 
The cross-vein situated near the end of the auxiliary vein (1O) . 

Gnophomyia. 

UMNOPHIUNI. 

1. Discal cell open; antennae apparently 2S-jointed in the $ (28). 

Polmera. 
Discal cell closed. ......... 2 

2. Marginal cross- vein wanting. .... Phyllolabis. 
Marginal cross-vein present. ....... 3 

3. Wings pubescent, Ulomorpha. 

Wings bare. .......... 4 

4. Seventh vein very short, abruptly incurved toward the anal angle 

(5) Trichocera. 

Seventh vein not unusual. ....... 5 

5. A supernumerary cross-vein between the auxiliary vein and the 

costa (p. 80, 5) Epiphragma. 

No such .supernumerary cross-vein (1, 9, 19)*. Limnophila. 

* A wingless form has recently been referred to this genus, with 
doubt, by Mr. Coquillett. 


9 o 


NORTH AMERICAN DIPTERA. 


ANISOMERINI. 

1. Three posterior cells; two submarginal cells (13). Anisomera, 
Four or five posterior cells; antennae of the $ sometimes much 

elongated. .......... 2 

2. The stigma occupies nearly the whole space between the tip of the 

auxiliary vein and the marginal cross-vein. . Eriocera. 
The stigma occupies but a small portion of the space between the 

tip of the auxiliary vein and marginal cross-vein. 

Penthoptera. 

AMALOPINI. 

1. Antennae composed of thirteen joints ..... 2 
Antennae composed of sixteen or seventeen joints. . . 5 

2. Two cross-veins between the first longitudinal vein and the anterior 

branch of the second vein. ....... 3 

Only one cross-vein between these veins. .... 4 

3. Front with a gibbosity behind the antennae (2). . Dicranota. 
Front without gibbosity. ..... Polyangseus. 

4. Five posterior cells; both branches of the fourth vein furcate (14) . 

Khaphidolabis . 
Four posterior cells; the posterior branch furcate. Plectromyia. 

5. Four posterior cells; wings pubescent. .... Ula. 
Five posterior cells; wings bare. ...... 6 

6. Anterior cross-vein nearly at right angles with the longitudinal axis 

of the wing. ......... 7 

Anterior cross-vein at a very oblique angle with the longitudinal 
axis of the wing, and parallel with the posterior cross-vein 
(p. 80, 1) Pedicia. 

7. Rostrum much longer than the head. . . . Ornithodes. 
Rostrum shorter than the head (4) .... Amalopis 

CYLINDROTOMINI. 

1. Five posterior cells; colors yellow and black. Cylindrotoma. 
Four posterior cells. ......... 2 

2. Antennal joints subcylindrical, elongated. .... 3 
Antennal joints subglobular; head and thorax conspicuously punct- 

ulate ......... Triogrna. 

3. Colors yellow and black. ...... Liogma. 

Colors brownish and grayish. .... Phalacrocera. 


9i 

PTYCHOPTKRIN^. 

1. First submarginal cell much shorter than the second. Idioplasta. 
First submarginal cell much longer than the second. . . 2 

2. Three posterior cells (12) ..... Bittacomorpha. 
Four posterior cells. ..... Ptychoptera. 


1. Legs long and slender, especially the tarsi; anterior branch of the 

second vein absent, obsolete or perpendicular, the rhomboid 
cell more or less square. ....... 2 

Legs not unusually slender, anterior branch of second vein present 
and oblique. ......... 5 

2. Antennae thirteen-jointed; male forceps complex. Dolichopeza. 
Antennas with less than thirteen joints; male forceps small, simple. 3 

3. Fifth posterior cell not in contact with discal cell. Megistocera. 
Fifth posterior cell in contact with discal cell. ... 4 

4. Head on a neck-like prolongation of the thorax; seventh vein short, 

running into the anal angle. . . . Brachypremna. 

Head more closely applied to the thorax; seventh vein terminates 

in the margin at some distance from the anal angle. Tanyprema 

5. Antennas of $ pectinate or sub-pectinate. .... 6 
'Antennae not pectinate. ........ 7 

6. Ovipositor of 9 long, sword-like. .... Xiphura. 
Ovipositor of 9 long but not sword-like (p. So, 4). Ctenophora. 

7. Three posterior veins arising from the discal cell, the two anterior 

sometimes arising together but the petiole always short (p. 80, 7) 

Pachyrrhina. 

Two posterior veins arise from the discal cell, the anterior one fur- 
cate, petiole always of considerable length. ... 8 

8. Antennas serrate; northern species. . . . Stygeropis. 
Antennae not serrate below. ....... 9 

9. Marginal vein wanting, but one marginal cell; antennal joints short 

with minute bristles. ...... Holorusia. 

Two marginal cells. ......... 10 

lo.Abdomen slender, very long; antennae composed of twelve joints. 

Longuria. 
Abdomen less elongate; antennae with thirteen joints (27). 

Tipula. 


II. FAMILY PSYCHODID^E. 

Thickly haired, minute flies, in appearance moth-like. 
Head small; ocelli wanting. Antennae as long as the 
head and thorax together, bead-like ; thickly haired ; 
composed of from twelve to sixteen joints; the two basal 
joints shorter and short-cylindric. Proboscis usually 
short; or more or less elongated (Ph Ic boto m u s) and 
rigid; palpi incurved and hairy; composed of four joints 
of nearly equal length. Thorax not very convex, with- 
out transverse suture; scutelluni rounded. Abdomen 
cylindrical, composed of from six to eight segments; 
male genitalia prominent. Legs short, densely hairy; 
claw r s small. Wings large, ovate or lanceolate in shape; 
when at rest lying roof-like over the abdomen ; densely 
covered with hair or tomentum, which also forms a fringe 
around their margin ; the costal vein continuous about 
the wing; veins strong, for the most part concealed be- 
neath the hair ; venation formed almost wholly by longi- 
tudinal veins; the anterior cross-vein is short and lies 
near the root of the wing and is often difficult of discern- 
ment ; the second longitudinal vein arises near the origin 
of the first and is furcate. Fourth vein furcate; between 
these two furcations there are usually two longitudinal 
veins, the precise homologies of which are uncertain ; the 
front one is often supposed to be an additional furcation 
of the second ; or it may be a furcation of the third occur- 
ring before the anterior cross-vein, a peculiar structure 
found elsewhere in diptera only among the Tipulidae 
(Ptychopterinee) . The vein just before the posterior furca- 
tion terminates near the tip of the wing. Fifth and sixth 
veins terminate in the border of the wing, as does also 

the seventh, which is, sometimes, very short. 

92 


PSYCHODID.E. 


93 


The members of this famity are often very minute, 
rarely exceeding the length of four millimeters ; they are 
observed in shady places, on windows, in outhouses, or 

V 

running about on leaves near streams of water, and will 
be readily recognized by their peculiar moth-like appear- 
ance; the}- run about nimbly, but their flight is weak. 
The larvae live in rotting vegetable material, in dung, or 
in water; they are peculiar in having both open spira- 
cles and tracheal gills ; the maxillae are imperfectly de- 
veloped, there are eye-spots on the head, and the segments 
behind the head are without feet, but are provided with 
sucking disks, in the aquatic forms at least. 


-Fig. 26. Psyc hod i else, i, Ps ychoda, wing; 2, Pericoma, wing 
(Eaton); 3, Sycora.v, wing (Eaton); 4, Trichomyia, wing (Eaton). 

TABLE OF GENERA. 

1. Two simple longitudinal veins between the forked veins. . 2 
One simple longitudinal vein between the forked veins. . 4 

2. The first simple vein arises from the forked vein much beyond the 

anterior cross-vein (Flebotomus!} . . Phlebotomus. 
The first simple vein arises near anterior cross- vein. . . 3 

3. The second simple vein ends at or near tip of wing (1) . Psychoda 
The second simple vein ends distinctly beyond tip of wing (2). 

Pericoma. 

4. The seventh longitudinal vein (the most posterior one) not much 

shorter than the sixth (4) ... . Trichomyia. 

The seventh longitudinal vein very short (3) . . Sycorax. 

ii 


III. FAMILY DIXID^E. 


Fig. 27. Di.va species; enlarged. 


After Kellogg. 


Rather small, slender, nearly bare species. Proboscis 
somewhat projecting ; palpi four-jointed; antennae long, 
the basal joints thick, those of the flagellum hair-like, 
and the joints indistinctly distinguishable. Eyes round, 
dichoptic ; no ocelli. Thorax strongly convex, without 
transverse suture ; scutellum transverse ; metanotum 
arched. Abdomen long and slender, composed of seven 
or eight segments, thickened posteriorly in the male, 
pointed in the female. Legs long and slender; coxae 
somewhat elongated; tibiae without terminal spurs. 
Wings comparatively large; auxiliary vein present, ter- 
minating in the costa before the middle of the wing ; the 
second vein arises from the first near the middle of the 
wing and appears to be the beginning of the third vein, 
which continues its direction while the second arches 
suddenly forward at or near the anterior cross-vein and 
is furcate ; fourth vein furcate ; four posterior cells pres- 

94 


DIXID^. 


95 


ent; the two basal cells complete; the anterior cross- 
vein is near the beginning of the third vein, where the 
second vein curves forward. 

The family Dixidae comprises about a score of known 
species belonging to the single genus Dixa. The genus 
has been placed among the Tipulidse and Culicidae, but 
is provisionally isolated into a separate family. The 
larvae are aquatic, living in ponds or slowly running 
w r ater; they resemble those of the mosquitoes. The flies 
are found in bushy, moist places about forests, and have 
been observed by Winnertz dancing in the air in s\varms. 


IV. FAMILY C 

Slender flies, for the most part characterized by the 
projecting, slender proboscis and the thickly plumose 
antennae of the males. Head small, subspherical ; eyes 
reniform ; ocelli wanting. Antennae slender, elongate, 
composed of fourteen or fifteen joints; first joint globose, 
the following elongated, nearly or quite cylindrical and 
beset with whorls of hair, forming, with but few excep- 
tions, in the male a dense plumosity, but shorter and 
less conspicuous in the female ; in the male the last two 
joints almost always more elongated and nearly bare. 
Thorax ovate, arched, but not projecting over the head, 
without transverse suture; scutellum narrow, uni- or 
trilobate; metanotum usually arched. Abdomen long 
and narrow, somewhat flattened, composed of eight or 
nine segments ; male genitalia prominent ; ovipositor 
short. Legs long and slender; coxae not elongate ; tarsi 
long; claws often denticulate, especially in the males. 


* -ad 


vtin 


Fig. 28. Venation of Culex. 

Wings long and narrow, while at rest lying flat over 
the abdomen; with six fully developed longitudinal 
veins reaching the costal margin ; the hind margin is 

96 


fringed with hair or scales and the costal vein encom- 
passes the wing ; auxiliary vein distinct, reaching to or 
beyond the middle of the wing; second, fourth and fifth 
longitudinal veins furcate; third vein simple, arising 
from the second angularly beyond the middle of the wing; 
anterior cross-vein situated near or even proximal of the 
origin of the third vein. Two basal cells present, elon- 
gate, the anal cell wide open. Veins of the wings cloth- 
ed with scales. 

The foregoing description and figure of the wing do 
not wholly agree with those of other writers. It is evi- 
dent, unless we change the nomenclature of the brachy- 
cerous flies, that the furcation of the second vein does 
not form a submarginal cell; the so-called 'first submar- 
ginal cell' is in reality the second marginal. Further- 
more, it is as clearly apparent that the so-called 'poste- 
rior cross-vein' is not the vein of that name among the 
brachycerous and cyclorrhaphous flies, but is, rather, the 
'discal' or 'discoidal cross- vein', or the 'anterior basal 
cross-vein'; or, at least, a cross-vein which has not yet 
received a definite name. 

Since the last edition of this work was published, in 
1896, the marvelous discoveries in the life histories of the 
Culicidse, and their agency in the transfer of disease, 
have given to the family an importance in man's econo- 
my second to that of no other group of insects. Indeed, 
one may say with entire truth that these little flies, or 
'gnats' as the English call them, are the most baneful 
and pestilential of all known insects. The microscopical 
parasites producing malaria, yellow fever and filariasis 
are now 7 known with certainty to be transferred by the 
agency of certain mosquitoes from one human being to 
another, and it is probable, though of course not certain, 
that if all the germ-bearing mosquitoes could be made 
extinct these diseases would at least cease to trouble 


9 8 


NORTH AMERICAN DIPTERA. 


. 29. Mochlonyx cinctipes. Female adult; enlarged. 
After J. B. Smith. 


99 


mankind. The parasitic microorganism is a small pro- 
tozoan which undergoes development in the red corpus- 
cles of the blood, destroying them, and there seems to be 
no way, in general at least, in which it may be transfer- 
red from one person to another save by the activity of 
these insects. Taken into the mosquito's stomach with 
the blood sucked up by the insect it there undergoes 
sexual regeneration, of which the ne\vly generated germs 
or 'blasts', penetrating the walls of the mosquito's stom- 
ach, reach the salivary glands, and are thence transfer- 
red with the poisonous saliva emitted by the insect into 
the wounds made by its puncturing 'bites'. 


Fig. 30. Cule.v taeniorhynchus. I, female adult ; 2, front claws 
of female; 3, front, 4 middle, 5, hind claws of male; all much enlarged. 
After J. B. Smith. 


IOO 


NORTH AMERICAN DIPTERA. 


Not all mosquitoes are criminals in this respect. Only 
certain forms of Anopheles (in its wide sense) are known 
to carry the germs of malaria ; while but a single species, 


I 


Fig. 31. Anopheles punctipennis, i, female adult; 2, female pal- 
pus; 3, genitalia; 4, part of wing vein showing scales; 5, front, 6, 
middle claws of male; all much enlarged. After J. B. Smith. 


101 


the Culex or Stegomyia fasciata, is so far known to cause 
the deadly yellow fever. But these disease-bearing spe- 
cies are widely distributed over the earth, accounting 
for the wide distribution of malaria and yellow fever. 


Fig. 32. Aedesfuscus. I, female adult; 2, female palpus; 3, male 
palpus; 4, front, 5, middle, 6, hind claws of male; all much enlarged. 
After J. B. Smith. 


I0 2 NORTH AMERICAN DIPTERA. 

Probably we shall yet learn of other mosquitoes which 
are culprits in these respects. 

This gravely important bearing of the mosquitoes in 
man's economy has given a tremendous impulse to their 
study, though not always w 7 ith the most happy results so 
far as their taxonomy is concerned. Whereas ten or 
twelve years ago only about one hundred and fifty spe- 
cies of the family were known, we now have an accred- 
ited list of Culicidse of nearly or quite six hundred spe- 
cies, and there are probably several hundred more yet 
awaiting discovery. 

It seems a fact that the mosquitoes present but few and 
slight structural differences among themselves ; the many 
closely related forms seem to indicate a late geological 
crudescence. Such organisms are always difficult to 
classify. The wing venation has acquired much fixity, 
whereas the many secondary sexual differences in the 
mouth-organs would indicate a late adaptation to blood- 
sucking habits. The Culicinse probably have developed 
from the corethrine type, which is doubtless an older 
type, now decidedly on the wane. Until within a few 
years scarcely a half dozen genera of the mosquitoes had 
been recognized by dipterologists, and they were based 
chiefly on the secondary sexual mouth characters. Within 
these few years, however, the numerous writers 011 this 
group of insects have proposed fully one hundred gen- 
era, for the most part merely subdivisions of the older 
genera, founded on minor characters, chiefly the shape 
and arrangement of the scales of the body and wings. It 
seems to be the consensus of opinion among other dipter- 
ologists that the use of such characters has been car- 
ried to an undue and even absurd extreme. Of course 
the first requisite in classification is that distinguishing 
characters shall be 'natural', that is genetic, not homo- 
plastic or parallel characters. When such are found it 


103 


really makes little difference how far they are carried, 
save that their use in one group, necessitates or stimu- 
lates the use of like minor characters in other groups. 
One cannot raise a genus of Culicidae to family rank, 
without raising all other genera of like degree pari passu. 
But I am firmly of the opinion that the scale characters 
are in a high degree artificial, and that their use will 


3 


Fig. 33. Aedes musicus. i, female adult; 3, claws of female front; 
6, hind claws of male; enlarged. After J. B. Smith. 


104 


NORTH AMERICAN DIPTERA. 


never be accepted by dipterologists in general. And 
secondary sexual characters should also be tabooed so 
far as possible, since they represent merely evolutional 
instability. 

The formation of so many genera from these slight 
characters, is, however, no worse than the attempt to 
classify and name genera and species purely from the 
larval stage, which has been done to a degree never be- 
fore attempted by scientific dipterologists. 

Upon the whole the characters made use of in the fol- 
lowing table, verbally modified from Dyar and Knab, 
come nearest to my own views of proper classificatory 
characters for the family. I am not able to test the table 
thoroughly, and cannot vouch for it, but I believe it to 
be the best that has so far appeared. The student ma}' 
also consult a recent table of the genera published by 
D. W. Coquillett.* 

The habits of the immature stages of the Culicidse are 
so familiar to all that little need be said here regarding 
them. 

The eggs are laid by the females upon the surface of 
stagnant or nearly stagnant water, in groups or singly, 
whence the young larvae, hatching, descend into the 
water to form those active little creatures of the rain- 
barrel, commonly known as 'wigglers'. The pupal stage 
is less active, passed in large part near the surface of the 
water, hanging by the respiratory tubes. The adult in- 
sect emerges from the pupal skin through a rent, using 
its discarded shell as a temporary raft until its wings 
are fully extricated. 

The following description of the larvae of the mosqui- 
toes is paraphrased from Dyar and Knab : 

* Bull. U. S. Dept. Agric. Tech. Ser. No. 11 (1906). 


105 


Fig. 34. Psorophora ciliata. i, female adult; 2, female palpus; 3, 
front; 4, hind claws of male; enlarged. After J. B. Smith. 


12 


io6 


NORTH AMERICAN DIPTRRA. 


Head well formed, enclosed in a chitinous covering; 
with compound eyes, single-jointed antennae, a group of 
hairs before the oral orifice, toothed mandibles, maxillae, 
and single-jointed palpi. Thoracic segments consolida- 
ted into a transversely elliptical flattened mass ; abdomen 
with nine slender and moniliform segments, the eighth 
with a dorsal, respiratory opening, often prolonged into 
a chitinous tube ; last segment furnished with a chitin- 
ous plate, and usually with four delicate anal append- 
ages. The body has setae in tufts or singly, usually 
more or less conspicuously feathered. From other aquatic 
nematocerous larvae, the mosquitoes are distinguished 
by the presence of the mouth-brush, the shape of the 
anal segment and the absence of abdominal feet. The 
larvae of Dixa and the Corethrinae are practicably indis- 
tinguishable from those of the Culicinae, save by minor 
characters.* 


35- Culicidse. i, Megarhinus, wing; 2, Megarhinus^ head, 
male; 3, Aedes, wing; 4, Hcemagogus, bead, female; 5, front claws 
of Hcemagogus, male; 6, Wyeomyia, head of female; 7, Corethra, hind 
tarsus. 

TABLE OF GENERA. 

Proboscis short, not adapted for piercing. . . Corethrinse. 
Proboscis much longer than the head, firm, adapted for piercing. 

Mosquitoes. ........ Culicinae. 

*I especially commend to the student interested in this family of flies 
the comprehensive and richly illustrated Report upon the Mosquitoes 
of New Jersey (1904), by Prof. J. \\, Smith. 


. I0 y 

CORETHRIN^. 

1. Hind metatarsi shorter than the following joint {Corethra* Coquil- 

lett). (fig. 29) ...... Mochlonyx. 

Hind metatarsi longer than the following joint. ... 2 

2. Small species; ungues simple. .... 3 
L/arge species (lomm); ungues bifid. . . . Pelorempis. 

2. Antennae verticillate (Sayomyia Coquillett) (7). Corethra. 

Antennae of male thickly clothed with long hairs; of the female 

with a basal and an irregular median circlet of hairs on each 

joint. ........ Corethrella. 


AFTER DYAR AND KNAB. 

1. Metanotum without setae (Culicini). ..... 2 

Metanotum with setae (Sabethini). ..... 15 

2. vScutellum evenly rounded, not lobed. ..... 3 

Scutellum distinctly trilobate. .....: 4 

3. Second marginal cell longer than itspetiole (fig. 31) Anopheles. 
Second marginal cell less than half as long as its petiole (1, 2) . 

Megarhinus. 

4. Hind tibiae near their tip with a row of seven to twelve closely 

set setae. .......... 5 

Hind tibiae with none to five sparsely set setae. ... 14 

5. Scutellum with its median lobe elongate, collar-like, not tubercu- 

larly prominent, ......... 6 

Scutellum with its median lobe distinctly prominent and tuber- 

1 li . I I . y 

6. Terminal antennal joints slender, long. . . Mansonia. 
Terminal antennal joints short, broad. . . . Aedomyia. 

7. Second joint of antennae very long, 14:1. . Deinocerites. 
Second joint of antennae moderately long, less than 8:1. . 8 

8. Second marginal cell less than half as long as its petiole. 

Uranotsenia. 
Second marginal cell at least nearly as long as its petiole. 9 

* My examination of the literature leads me to quite different con- 
clusions than those of Coquillett regarding the types of Corethra and 
Mochlony.r. There is no call for disturbing these names so long es- 
tablished. 


log NORTH AMERICAN DIPTERA. 

9. Head with a distinct neck, the occiput broad and exposed (fig. 34) . 

Psorophora. 
Head without distinct neck, appressed to the thorax. . 10 

10. Cross-veins approximated and nearly in line with the ha<-al sec- 

tion of the third vein. ... . Culiseta. 

Cross-veins not approximated, separated by at least the length of 

the posterior. ......... 1 1 

11. L,ast segment of the female abdomen not extensile, large, trun- 

cate; male genitalia with the harpes slender, columnar, with 

bent, spined tip Tseniorhynchus. 

Last segment of the female abdomen extensile, slender; male 
genitalia with harpes broad, concavely curved. . . 12 

12. Clypeus bare. ......... 13 

Clypeus with dense appressed scales. . . . Stegomyia. 

13. Prothoracic lobes approximated (4,5). . Hsemagogus. 
Prothoracic lobes well separated (figs. 32, 33). . Aedes. 

14. Empodia large. ........ Lutzia. 

Empodia small (fig. 30). ...... Culex. 

15. Clypeus without hairs. ........ 16 

Clypeus hairy on the sides. ..... Joblotia. 

16. Prothoracic lobes contiguous, densely hairy. . Sabethes. 
Prothoracic lobes well separated. . . . . . .17 

17. Eyes narrowly separated by the front; proboscis rather short, 

swollen at tip. ......... 18 

Eyes contiguous at vertex. ....... 19 

18. Hind tarsi with two claws, normal (6). . . Wyeomyia. 
Hind tarsi with but a single claw. . . . Limatus. 

19. No erect forked scales on occiput; proboscis longer than the body. 

Phoniomyia. 

With a row of erect forked scales on occiput; proboscis not longer 
than the body. ......... 20 

20. Face normal, smooth. .... Lesticocampa. 
Face with a conical process above the clypeus. Runchomyia. 

The following synonymy is given by Dyar and Knab: 

Anopheles Meigen: Myzomyia Blanch., Cycloleppteron Theob: 
Nototricha Coq., Cellia Theob., Arribalzagia Theob., Coelodiazesis 
D. and K. 

Mansonia Blanch.: Pneuinaculex Dvar. 


CULICID.U I09 

Teeniorhynchus Lynch: Coquillettidia Dyar. 

Aedes Meigen: Ochlerotatus'L t \n.c.\\,Hetoronycha Ly nch, Jan thin o- 
soma Lynch, Conchyliastes Coq., Grabhamia Theob., Howardina 
Theob., Culiselsa Felt. Culicada Felt, Ecculex Felt, Protoculexz\\., 
Pseudoculex Dyar, Gymnometopa Coq., Lepidoplatys Coq., Feltidia 
Dyar, Ceratocystia D. & K. 

Haemagogns Will.: Cacomyia Coq., Stegoconops Lutz. 

CulexLinn.: XeoculexTlyar, Culicella Felt, Melanoconion, Theob., 
Tinolestes Coq. , Micr cedes Coq. , Isostomyia Coq. , JMochlostyrax D.&K. 

Sabethes R.-D.: Sabethoides Theob. 

Wyeomyia Theob. : Dendromyia Theob. 

Limatus Theob.: Simondella Laveran. 

Joblotia Blanchard: Trichoprosopon Theob. 


V. FAMILY CHIRONOMID^. 

Gnatlike flies of slender form, seldom reaching ten mil- 
limeters in length; the males conspicuous for their plu- 
mose antennae. Head small, spheroidal, more or less 
concealed by a projecting, hoodlike thorax. Antennae 
threadlike or beadlike with not less than six nor more 
than fifteen joints ; in the male usually with a long dense 
plumosity; in the female with inconspicuous hairs and 
sometimes with a smaller number of joints; the first joint 
short and thick. Byes reniform or oval ; ocelli wanting 
or rudimentary; proboscis short; palpi three or four- 
jointed; the last usually elongated. Thorax ovate, very 
convex, usually projecting above in front more or kss 
over the head; without transverse suture; scutellum 
small, hemispherical. Abdomen usually narrow and 
long, composed of eight segments; hypopygium project- 
ing forcep-like ; ovipositor very short, but little devel- 
oped ; legs usually slender and long ; especially the front 
pair; coxae of moderate length. Tarsi often much elon- 
gated. Wings narrow and long; bare or uniformly hairy; 
anterior veins stronger and darker colored than the others; 
auxiliary vein complete, but usually very weak and slen- 
der; second longitudinal vein usually wanting; third 
vein sometimes forked close to its origin, the upper branch 
often rectangular and having the appearance of a super- 
numerary cross-vein ; fourth vein often, the fifth usually, 
furcate ; posterior cross-vein often wanting ; the costal 
vein terminates near the tip of the wing at the termina- 
tion of the third vein. 

This family comprises a large number of very delicate, 
often minute flies, commonly known as midges, which 

110 


CHIRONOMIM. TII 

have not been much studied by entomologists ; about 
one thousand species are known throughout the world. 
They will be distinguished from the mosquitoes, \vhich 
they resemble very much, by the costal vein not being 
continuous on the posterior side of the wing. The an- 
tennae are usually conspicuous, especially in the males, 
although agreeing in this respect with male mosquitoes. 
The larvae are soft-skinned, worm-like, often blood-red 
in color and usually aquatic, as are also the active pupae, 
though some live in decomposing vegetable matter, or in 
the earth. These midges are often seen, especially in 
the early spring or in the autumn, in immense swarms, 
dancing in the air, and have doubtless in many cases 
given rise to exaggerated stories of mosquitoes. Over 
meadows in the Rocky Mountains the writer has seen 
them rise at nightfall in the most incredible numbers, 
producing noise like that of a distant waterfall, and audi- 
ble for a considerable distance. While at rest they 
usually raise their forelegs in the air and keep them con- 
stantly vibrating. Aquatic larvae may be frequently met 
with in standing water, often extremely delicate little 
creatures, so transparent as to be hardly distinguishable; 
they have been dredged from nearly one thousand feet 
below the surface of Lake Superior. 

Most of the species are inoffensive, or actually benefi- 
cial as scavengers. There are some, however, belonging 
to the genus Ceratopogon and its allies, and known gen- 
erally as midges, or punkies, which have the power of 
sucking blood and are extremely annoying. In the White 
Mountains, at the seashore, along mountain streams gen- 
erally, and in the West Indies they are especially trouble- 
some. The larvae live in the flowing sap of trees, in 
decaying vegetation, under fallen leaves, or in water. 

I have included in this family, and have added to Pro- 
fessor Johannsen's table the diagnosis of the genus 


112 


NORTH AMERICAN DIPTKRA. 


Fig. 36. Chironomidse. i, Ablabesmyia, wing; 2, Chironomus, 
wing; 3 Corynoneura, wing (Johannsen); 4, Culicoides, wing; 5,Jo- 
hannseniella, wing ; 53, Johannseniella^ antenna ; 6, Orthocladius ^ 
wing; 7, Bezzia, wing; ya Bezzia, front leg; yb, Bezzia, palpus; 8, 
Diamesa, wing (Johannsen); 9, Procladius, Tanypus, wings (Jo- 
hannsen); 10, Johannseniella, Palpomyia wings (Johannsen); u, 
Stenoxemis, wing (Coquillett); 12, 13, 14, Ceratopogon (empodinm of 
12, omitted) ; T3a, Ceratopogon, antenna; i3b, Ceratopogon palpus; 
15, Qamptocladius (Wulp). 


CHIRONOMID.E. 113 

Stenoxenus Coquillett, (fig. n) referred by its author to 
a new family. Mr. Coquillett's interpretation of the 
neuration is clearly wrong: the fourth vein is coalescent 
with the third and first for a considerable distance, but 
all three veins are distinct distally and of the usual Chi- 
ronomid structure. The genus was based upon a single 
female specimen without antennae, so that its more exact 
position in the family must await further study. 

TABLE OF GENERA. 

P.V PROF. O. A. JOHANNSEN. 

1. First, third and fourth longitudinal veins coalescent for the larger 

part of the distance between the humeral cross-vein and the 
posterior branch of the fourth; third vein long, not connected 
with 'the first vein by a cross-vein; front concave (11). 

Stenoxenus. 
Fourth vein not at all coalescent with the first. ... 2 

2. Wings short, strap-like, thickened, and without distinct venation. 

Eretmoptera. 
Wings normal. ......... 3 

3. Posterior (i. e. the 'anterior basal') cross-vein present, the second 

basal cell complete. ........ 4 

Posterior cross-vein absent, no second basal cell. ... 14 

4. Antennae with fifteen joints in both sexes, rarely twelve or four- 

teen jointed in the female; long plumose in the male, penulti- 
mate joint elongate, apical joint very small. (Tanypus, sens. 
lat.) 5 

Antennae of the male with nine or with fourteen joints, the female 
with seven or eight joints. . . . . . . .12 

5. Wings bare, .......... 6 

Wings hairy. . . . . ; . . . . . . 9 

6. Fork of the fifth vein petiolate. ...... 7 

Furcation of the fifth vein slightly proximad of the posterior 

cross-vein. .......... 8 

7. First vein forked at its extremity (9) . . Procladius Skuse. 
First vein simple Psilotanypus Kieffer. 

8. First vein forked at its extremity. . Anatopynia Johannsen. 
First vein simple. ..... Protanypus Keiffer. 


H 4 NORTH AMERICAN DIPTERA. 

9. Fork of the fifth vein petiolate. ...... 10 

Furcation of the fifth vein slightly proximad of the posterior 
cross-vein. . . . . . . . . . .11 

10. First vein forked at its extremity (9) . . . . Tanypus. 
First vein simple Trichotanypus Kieffer. 

11. First vein forked at its extremity. Ablabesmyia Johannsen. 
Fork of the first vein and the second vein pale and indistinct; an- 
tennae of the female twelve jointed. . leoplastus Skuse. 

12. Fourth tarsal joint shorter than the fifth, obcordate. . . 13 
Fourth tarsal joint linear. . . . Prodiamesa Kieffer. 

13. Antennae of the male with fourteen plumose joints; terminal joint 

very long; antennae of the female with seven or eight short 
haired joints (8) Diamesa. 

Antennae of both sexes short-haired, the terminal joint oval; those 
of the male with nine, of the female with eight joints. 

(The female does not seem to differ from Dianicsa.} 

Eutanypus. 

14. Thorax with a median longitudinal fissure; small species, usually 

with blackish wings having white markings. Chasmatonotus 
Thorax without longitudinal fissure. . . . . . 15 

15. Claws cleft; first vein ending not far from the tip of wing; anten- 

nae seven jointed in both sexes. . . Telmatogeton. 

Claws not cleft, though sometimes toothed on the side. . 16 

16. First vein thickened at apex, anal angle of wing obsolete; antennas 

of the male with ten or eleven joints, of the female with six 

joints; very minute flies (3) .... Corynoneura. 

Not with all the above characters. . . , . 17 

17. Fourth longitudinal vein simple; antennae of male with foiirteen 

joints, closely sessile, plumose, the terminal joint cylindrical; 
antennae of the female with seven joints, short haired; (second 
and third joints sometimes more or less coalescent) . Chirono- 
mns, sens. lat. ......... 18 

Fourth longitudinal vein furcate; antennae of both sexes fourteen 
jointed, except with Tersest hes. . . . . . 25 

18. Fourth tarsal joint obcordate, shorter than the fifth; front meta- 

tarsus shorter than its tibia; wing under low magnification bare. 

Thalassomyia. 
Fourth tarsal joint linear. ....... 19 


CHIRONOMID^E. II5 

19. Wings bare. .......... 20 

Wings hairy. .......... 23 

20. Front metatarsi as long or longer than tibiae (2). Chironornus. 
Front metatarsi distinctly shorter than their tibiae. . . 21 

21. Legs, especially the front pair, sharply black and white annulate. 

Cricotopus. 
Legs not so banded. ........ 22 

22. Posterior branch of fifth vein sinuous (15). Camptocladius. 
Posterior branch of the filth vein straight or gently arched (6) . 

Orthocladius. 

SUBGENERA OF ORTHOCLADIUS. 

a. Eyes hairy Trichocladius Kieffer. 

Eyes bare. ..... b. 

b. Pulvilli large, empodium long and filiform. 

Psectrocladius Kieffer. 
Pulvilli wanting c. 

c. Empodium filiform. . . . Dactylocladius Kieffer. 
Empodium not distinct. .... Orthocladius. 

23. Front metatarsi longer than their tibiae; anal angle of wings but 

slightly" developed; anterior cross- vein very short and some- 
times difficult to distinguish Tanytarsus. 

Front metatarsi shorter than their tibiae. ... 24 

24. Thorax produced conically, nipple-like, in front over the head; 

hind tibiae dilated and hairy. . . . Eurycnemus. 
Thorax moderately produced, hind tibiae not dilated. 

Metriocnemus. 

25. Antennae with thirteen joints (counting the large basal) wings 

with anal angle; palpi three-jointed, penultimate joint swollen. 

Tersesthes. 

Antennae with fourteen joints in both sexes, the terminal joint 
only moderately elongated; male antennae plumose (Ceratopo- 
gon, sens, lat.) ..... . 26 

26. Last tarsal joint with empodium, either distinct or developed pul- 

villiform; wings usually hairy; femora without spines, tarsal 
claws equal. ....... 27 

Last tarsal joint without empodium; wings usually bare. . 28 

27. Empodium well developed, almost as long as the claws, these with- 

out setae (12, 13, 14) Ceratopogon. 


Il6 NORTH AMERICAN DIPTRRA. 

SUBGENERA OF CERA'fOPOGON. 

a. Wings bare Atrichopogon Kieffer. 

Wings hairy. . b. 

1). Hind metatarsus longer than the following joint, sometimes in 
the male only equal. .... Ceratopogon. 

c. Hind metatarsus shorter than the following joint, sometimes 
equal in the female. . . . Forcipomyia Megerle. 

Empodinm not so distinct, less than half as long as the claws, the 
latter with setae at base; hind metatarsus always longer than 
the following joint. (Oecacta is probably a synonym) (4). 

Culicoides Latreille. 

28. A cross-vein between the first and third veins. ... 29 
No cross-vein between the first and the third veins. Bezzia Kieffer. 

SUBGENERA OF BEZZIA. 

a. Femora without prominent spines on the underside. 

Probezzia Kieffer. 

b. Some or all femora with spines Bezzia. 

29. Femora unarmed, that is without stout black spines on the under 

side (Ceratolophiis Kieffer.) (5) Johannseniella Williston. 

Some or all the femora spinose beneath. .... 30 

30. Hither fore or hind femora much thickened. . . . 31 
Femora not noticeably thickened (1O) . Palpomyia Megerle. 

SUBGENERA OF PALPOMYIA. 

a. Antennae of both sexes verticillate with short hairs. 

Alasion Rondani. 

Antennae of the male plumose. b. 

b. Last tarsal joint with two rows of coarse spines below. 

Sphseromyas Stephens. 

Last tarsal joint hairy below. . . Palpomyia Megerle. 

31. Fore femora thickened. , Heteromyia. 
Hind femora thickened. .... Serromyia Megerle. 

ADDITIONAL GENERIC REFERENCES FOR THE CHIRONOMID^). 

Johannsen. Bui. 86. N. Y. State Museum 1905. (Ablabesmyia, Ana- 
topynia) . 

Kieffer. Bui. Soc. Entom. France. 1899. 

Ann. Soc. Sc. Brux. XXX. 1906. 
" Genera Insectorum. Chironomidae. 1906. 

Latrielle. Gen. Crust, et Ins. IV. 1809. (Culicoides.) 

Megerle. In Meigen's System. Beschr. Eur. Zweifl. I. 1818. (For- 
cipomyia, Serromyia, Palpomyia). 

Rondani. Prodromus. II. 1857. (Alasion). 

Skuse. Proc. Linn. Soc. N. S. Wales. IV. 1889. (Procladius, Iso- 
plastus) . 

Stephens. Catalogue Brit. Ins. II. 1829. (Sphaeromyas.) 

Williston. Journal N. Y. Ent. Soc. XV. March, 1907. 


VI. FAMILY CECIDOMYID^E. 


Fig. 37. Diplosis pini-radiat(r< enlarged. After Kellogg. Eggs, 
pupa, larva, 'breast-bone' and imago. 

Small, slender flies with broad wings, and long anten- 
nae and feet. Head small; eyes round or reniform, some- 
times holoptic ; ocelli usually wanting; antennae long, 
cylindrical or bead-like, composed of a large number of 
joints ten to thirty-six; in many species the joints 
beaded or petiolate and verticillate, especially in the $ ; 
proboscis short, very rarely elongated; palpi usually 
with four joints. Thorax ovate; more or less convex, 
without transverse suture ; abdomen composed of eight 
segments; hypopygium composed of a pair of projecting 
hooklets; ovipositor sometimes much elongated. Legs 
long and slender; coxae not very long; tibiae without 
terminal spurs; the first joint of tarsi sometimes very 
short. Wings large, usually hairy, narrowed at the root, 
without alula; at the most with five, usually with but 
three longitudinal veins; viz, the first, the third, and the 
fifth; the fourth and the sixth sometimes present; the 
humeral cross-vein indistinct, or wanting; costal vein 
enclosing the entire wing; veins all weak; the fifth usu- 
(13) IJ 7 


IZ 8 NORTH AMERICAN DIPTERA. 

ally furcate; anterior cross- vein very near the root of the 
wing, often appearing as the beginning of the third vein, 
the real origin of the third vein having the appearance 
of a short cross- vein; only one basal cell present. 

The family Cecidomyidae includes a very large number 
of frail, delicate, often very minute flies, but is of the 
greatest interest to the biologist as well as the economic 
entomologist. At present about 600 species are known 
from Europe alone. 

The egg of the Cecidomyidae is somewhat elongated, 
rounded at both ends, orange-yellow or white in color. 
The time required for hatching is very variable and de- 
pends upon the weather, sometimes requiring a very few 
hours, but more generally a few days or even weeks. 
The larval food is almost wholly vegetable. The larvae 
of some species have been bred from decaying wood and 
bulbs, others from under the bark of trees, or from fungi. 
But the great majority prefer living plants, attacking 
the soft and green parts. Most of the larvae are mono- 
phagous, living almost exclusively on a single kind of 
plant, or at least closely allied plants; but there are cer- 
tain exceptions, such as C. sisymbrii, which is said to 
form the gall in spring on the barberry, and later in the 
season on a nasturtium. There are certain others which 
are inquilinous, that is guests or parasites in galls formed 
by other Cecidomyids. Finally, some live parasitically 
in the society of plant lice. Not a few, such as the Hes- 
sian fly, live upon the surface of plants, or in the axils 
of their leaves; but the greater number penetrate inside 
the plant, producing the so-called galls. Every part of 
the plant from the root to the flower and the fruit is lia- 
ble to such attacks. With a few rare exceptions, each 
species attacks the same part of the plant and deforms it 
in the same manner. The galls cause deformations and 
excrescences attached to the stalk, stems, or flowers, de- 


CECIDOMYID^B. 


119 


15 


Fig. 38. Cecidomyidae. i, Lasioptcra; 2, Epidosis; 3, Cecidomyia; 
4, Hornioniyia; 5, Trichopteromyia; 6, Lestremia; 7, IMiastor; 8, 
Spaniocera; 9, i'atocha; 10, ('olpodia; u, Heteropeza; 12, Asynapta; 
13, M'inneytzia; 14, Diplosis (Lestodiplosis}; 15, Winnertzia. 

stroying the plant-tissue. When first hatched the larvae 
are colorless and translucent, with the alimentary canal 
showing through the skin greenish. Later in life they 
assume different shades of red or yellow. They have the 
extraordinary number of fourteen segments, thus forming 
an apparent exception to the larvae of all other insects, 
which as a general rule, have thirteen. The supernu- 
merary segment is placed between the head and first 
thoracic segment. The larvae have nine pairs of stigmata 
along the sides of the body apparent as more or less nip- 
ple-shaped projections. The head is not differentiated; 


I20 NORTH AMERICAN DIPTKRA. 

the jaws are rudimentary and there are large two-jointed 
palpi or antennae. The last abdominal segment is smooth 
and rounded, sometimes with tubercles or a pair of horny 
processes which are said to be used by the larvae in leap- 
ing. On the under side of the body at the junction of 
the first thoracic with the supernumerary segment there 
is a horny, more or less elongated appendage whose use 
or homology is unknown. It varies in shape in different 
species, the free end sometimes terminating in two points, 
sometimes in one, sometimes toothed and serrated. This 
organ, the spathula sternalis of Mik, has been called by 
Osten Sacken the 'breast bone'; in England it is known 
as the 'anchor process'. (See figure of Diplosis pini-radi- 
a/tz}. By some it is thought to be a pseudopod; by others 
the mentum; and Miss Ormerod believes its function is 
that of a scraper or digger in obtaining food from the 
stems. More probably its use is for locomotion, or for 
changing the position of the larvae in its cocoon or case. 
The motions of the larvae are usually slow, save of 
those which live on the surface of leaves. Those which 
change their abode before assuming the pupa state be- 
come very active about the period of metamorphosis. A 
very great activity was observed by Winnertz in some 
such larvae after a thunder storm. They left their hiding 
places under ground and crawled about restlessly for 
some time; repeating these actions after every thunder 
storm, some even two months after leaving their galls. 

Owing to their rudimentary mouth-parts it seems evi- 
dent that the larvae must feed upon juices only, and that 
they need very little nourishment is shown by the fact 
that they attain their full growth and development in a 
gall just large enough to enclose them, apparently her- 
metically sealed and for the most part with hard walls. 
It is probable that they absorb nourishment in a quiescent 
state. As many as sixty individuals have been known 


CECIDOMYIM. I2T 

to live in a single gall. What causes the galls is not 
easy to say; probably some peculiar irritation produced 
by the insect. It is probable that the larvae generally 
do not undergo moulting like most dipterous larvae. 
Before assuming the pupa state some larvae leave their 
galls and conceal themselves under ground, in dry leaves 
and moss or under the bark of trees; while others, on 
the contrary, complete their transformation within the 
gall itself. The pupae are generally, but not always, en- 
closed in the cocoon, which Winnertz says is produced 
by an exudation or excretion from the larvae and is not 
spun. Larvae which had fastened themselves to the leaf 
were surrounded in twenty-four hours by a white halo of 
thread-like particles like spicules or crystals, the larvae 
remaining almost wholly motionless. The cocoon is com- 
pleted within a few days but even then shows no traces 
of a genuine web. There seems to be no doubt, how- 
ever, but that they do in some cases actually spin a 
cocoon, as is so frequently the case among the fungus- 
gnats. The change to the pupa state is marked by an 
alteration of color, the anterior segments of the larvae 
become distended, and the legs, wings, and antennae de- 
veloping and rapidly attaining their full pupal dimen- 
sions. 

The period of pupation is very variable, depending 
upon warmth and moisture. The development is retarded 
by cold, though they are capable of withstanding a very 
low degree of temperature. 

One of the most remarkable things in the biology of 
these or any other insects was discovered by Wagner in 
1860. According to this scientist, the larvae of certain 
species belonging to the genus Miastor, and which live 
under the bark of trees, produce from ovary-like organs 
a number of eggs which hatch within the abdominal cav- 
ity of the parent and there remain, feeding upon the 


122 NORTH AMERICAN DIPTERA. 

abdominal tissues which surround them, until they are 
consumed. They then escape to increase in size and pro- 
duce another generation in the same remarkable manner. 
These series of asexual reproductions are repeated until 
finally, from the last brood, pupae are developed which 
undergo their transformation into imagines, and from 
which a new series of eggs, agamic broods of larvae and 
pupae in their turn result. There are other instances cf 
paedogenetic reproduction among diptera, but none so 
interesting as this. 

This family contains some of the 'most destructive of 
all insects in man's economy, and perhaps the most im- 
portant of these is Cecidomyia (Mayetiola) destructor-, com- 
monly called the Hessian Fly, from the belief, probably 
erroneous, that it was first introduced into this country 
in straw brought by Hessian troops during the Revo- 
lution. 

The fly is very small, but little more than an eighth cf 
an inch in length, of a prevailing black color, with the 
abdomen pinkish or brownish. There are two broods, in 
spring and autumn. The female deposits her eggs, one 
or two at a time, on the upper side of the leaves of wheat, 
to the number of from eighty to a hundred, or even more. 
Hatching in from four to eight days, if the weather is 
favorable, the yellowish red larvae crawl downward en 
the leaves until they insert themselves between the leaf 
and the stalk. Here they remain quiescent, growing by 
means of imbibition or absorption of the juices of the 
plant, until they reach the size cf a small grain of rice. 
The larvae that are hatched in April, in a few 7 weeks as- 
sume the pupa state, called the flax-seed stage. In Aug- 
ust the second brood appears, the female of which deposits 
her eggs in young winter wheat or other grain, where the 
larvae soon hatch and acquire the flax-seed condition in 
a few weeks, or by November, in which condition they 


CECIDOMYIM;. 


123 


pass the winter. In England there is but one brood, that 
of early summer, and the fly is not nearly so injurious to 
growing grain. 

I give two tables of the genera. The first is that of the 
previous edition of this work with minor modifications, 
and is nearly that of Wulp, Schiner, Winnertz and H. 
Loew, with additions. The figures illustrating these 
principal groups are, for the most part, taken from Wulp, 
and are of typical forms in the sense of Kieffer. In ad- 
dition I give a transcription of Kieffer's table as publish- 
ed by him in 1898 (Bull. Soc. d'Hist. Nat. Metz.), with 
certain abbreviations, especially of those characters de- 
rived from the structure of the genital organs, characters 
which I view with suspicion; and I have modified his 
terminology in accordance with the true conception of 
the dipterous venation, since Kieffer's terminology is 
only a makeshift, not based upon comparative studies, 
Some cf Kieffer's genera are evidently founded upon 
characters which would have been considered of generic 
value by the older writers, but, for the most part, they 
are merely permutations of what have, hitherto, been 
considered as specific characters, and I am convinced 
that some of them, as he defines them, are in a high de- 
gree artificial. One should always be suspicious of char- 
acters which permit perfectly parallel subdivisions in 
parallel phyla, for one must be assured that the charac- 
ters selected for primary subdivisions are not really ho- 
moplastic and of secondary importance, and it is apparent 
that some other writer w r ith different views of the relative 
importance of these characters might properly revolu- 
tionize the whole system. Furthermore, it will be appar- 
ent that Kieffer in some places ignores as of slight or 
minor value characters which in other places he raises 
to higher rank. His 'pelote unique', 'trois pelotes', 
'crochets bi fides' and 'crochets simples', as well as the 


I24 NORTH AMERICAN DIPTERA. 

never ending permutations of palpal and antennal joints, 
are repeatedly used and according to his view are wholly 
homoplastic characters, while it is seriously to be con- 
sidered whether many of them are not of real genetic 
origin, and consequently untenable in their subdivisional 
and repeated uses. Older writers had recognized many, 
if not most of these characters, but had refrained from 
using them. 

In other words, I consider the present classification 
offered by Kieffer as largely artificial and consequently 
not permanent. But the table will call the attention of 
the student to many minor characters which he would 
otherwise be very apt to overlook. 

I do not accept the contention of Karsch, with which I 
have long been familiar, that the names Cecidomyia and 
Diplosis should be differently applied or abandoned. 
Nor can I agree with Professor Aldrich that these changes 
have been threshed out in Europe. I can find no writer 
whose opinion is authoritative who has accepted them, 
nor did Kieffer. On the contrary Osten Sacken, whose 
opinion I value more than that of any other recent 
writer, has steadily opposed not only these changes, 
but the apparently unnecessary reduplication of the gen- 
era, for it must be remembered that Kieffer alone has 
proposed and adopted about fifty new 'genera'. Hendel, 
in reply to Osten Sacken's objections, has said that gen- 
era exist in nature, and that all we have to do is to 
recognize them a remarkable declaration from a nat- 
uralist of the twentieth century. I suppose he would 
permit 'Nature' to occasionally revise its genera a la De 
Vries! While it is true that the typical species of Meigen's 
genus Cecidomyia is not included in that genus as accept- 
ed by L,oew and in this work, but is included under 
Diplosis, it is also true that rigid rules of priority can not 
be extended to the works of many of the early writers. If 


CECIDOMYID^E. 125 

they are, not a few other revolutions of a similar charac- 
ter would impend, notably that of the genus Milesia, as I 
have made clear in my Synopsis of the North American 
Syrphidse. 

In brief, the classification, or rather the nomenclature 
of this family is still in a more or less chaotic condition, 
and will be so until much more study has been given to 
the insects, especially those of America and Asia. As 
Aldrich has said, there is no more fertile field in all dip- 
terology for thorough, exhaustive, ethologic, morpho- 
logic, taxonomic and phylogenic studies than among the 
Cecidomyidse. But there are many difficulties in their 
stud} 7 . Doubtless if Kieffer's principles of generic sub- 
division are accepted, there are a host of new 'genera' to 
be discovered in North America, for the permutations of 
antennae, palpi and tarsi are by no means exhausted. 
My advice is, however, for the non-specialist to go very 
slowly indeed in adding to what may prove to be an 
already unnecessary confusion. 

TABLE OF GENERA. 
(For the most part in their wider sense.) 

Fourth longitudinal vein wanting. . . . Cecidomyinse. 
Fourth longitudinal vein present (ocelli present) . Lestreminse. 

CECIDOMYIN^. 

1. First tarsal joint shorter than the following one. . . 2 
First tarsal joint longer than the following one. ... 14 

2. Fifth longitudinal vein not furcate. (8) . . . Spaniocera. 
Fifth longitudinal vein furcate. . . . . . 3 

3. First and third longitudinal veins approximated to the costa, dis- 

tinguishable \\ith difficulty; costa tomentose. . . . 4 

Third longitudinal vein distinctly separated from the first. 6 

4. Fifth longitudinal vein furcate near the middle. . . 5 
Fifth longitudinal vein furcate at base, giving an appearance of 

two longitudinal veins. (See DD, p. 127.) 


I2 6 NORTH AMERICAN DIPTERA. 

5. Proboscis much elongated, directed downward. Clinorhyncha. 
Proboscis short (1) Lasioptera. 

6. Antennae bead-like, the joints verticillate. ... 7 
Antennae cylindrical, the joints approximated, not petiolate, pro- 
vided with short, close hairs; the third vein terminates at or 
beyond the tip of the wing. . . . Asphondylia. 

7. The third longitudinal vein terminates in the costa before the tip 

of the wing (3) , Cecidomyia. 

The third vein terminates in the costa at or beyond the tip of the 
wing. ..... ... 8 

8. Thorax highly arched, hood-like over the head (4). Hormomyia 
Thorax only moderately arched. ...... 9 

9. Wings with but three longitudinal veins, the first, third and fifth. 10 
Wings with apparently four longitudinal veins, that is the first, 

third and, two in place of the fifth, the furcation taking place 
so near the root of the wings as to give the appearance of an 
additional longitudinal vein. ...... 13 

10. The anterior cross-vein, that is the vein arising from the root of 
the wing and connecting with the third vein nearly where it 
arises from the first, is curved S-shaped. . . . . u 
The anterior cross-vein is nearly straight, apparently the begin- 
ning of the third vein. ....... 12 

u. Wings very long and narrow (1O). . . . Colpodia. 

Wings not more than three times as long as wide (2). Epidosis 

12. Joints of the antennal flagellum petiolate, in the male with two 

bead-like swellings on each joint (14) . . . Diplosis. 

Joints not petiolate, or at most the males with a single bead-like 

swelling on each joint. ...... Dirhiza. 

13. Palpi large, with the last joint elongated, anterior cross-vein 

S-shaped Asynapta. 

Palpi small, the last joint not or but little longer than the penulti- 
mate; anterior cross-vein but little curved (13) . Winnertzia. 

14. Wings with but two longitudinal veins, the first and fifth, the lat- 

ter not reaching beyond the middle of the wing (11) . 

Heteropeza. 
Wings with three longitudinal veins, the first, third and fifth. 15 

15. Fifth vein furcate. ...... .16 

Fifth vein simple, not furcate (7) Miastor. 


CECIDOMYIM;. 127 

16. First and third veins approximated (Diomyza). Lasiopteryx. 
First and third veins not approximated (5) . Trichopteromyia, 


1. Fourth longitudinal vein simple. ...... 2 

Fourth longitudinal vein furcate; the two 'branches of the fifth, 

when present, are divergent at base of the wing, giving the ap- 
pearance of longitudinal veins. .... .4 

2. Fifth longitudinal vein furcate near base. . Strobliella K. 
Fifth longitudinal vein furcate near its middle (Joannisia K., Pe- 

roniviii K., H'asinuniella K., firyomyia K., Prionellus K., 
Aprionus K., Monardia K.) ... 3 

3. Antennae composed of from fourteen to twenty-five joints, the 

joints petiolate in the male. . . . Campylomyza. 

Antennae composed often (male) , or six or eight (female) joints, 

the joints petiolate in neither sex. . . Micromyia. 

4. The costal vein reaches to or exceeds the tip of the wing. Catocha 
The costal vein does not reach the tip of the wing (9) . . 5 

5. Only one vein behind the forked cell. . . Tritozyga. 
Two veins behind the forked cell (6) . . . . Lestremia. 

TABLE OF GENERIC DIVISIONS (Kieffer). 

CECIDOMYIN^. 

A. First joint of tarsi shorter than the second; wings rounded at ex- 
tremity; no ocelli. 

B. Wings with squamje on anterior border; claws bifid. 
C. First two longitudinal veins very close to the costa. 

D. Three longitudinal veins, the first, third and fifth, the 

fifth furcate near the middle. 

1. Proboscis short. . . Lasioptera. 

2. Proboscis elongate. . . . Clinorhyncha. 
DD. Four longitudinal veins, that is the fifth is divided near 

base of wing. 

3. Thorax attenuated at neck. . Acorhynchus R. 

4. Palpi with one joint. . . Baldratia K. 

5. Palpi with four joints. . . Choristoneura L. 
CC. Third longitudinal vein, at least, remote from costa. 

E. Empodia simple. 

6. The third longitudinal vein terminates at or near 

extremity of wing. . . . Cecidomyia. 

7. The third longitudinal vein terminates at some dis- 

tance before tip of wing. . . Perrisia Rond. 

8. Flagellar joints with two verticils; alike in both sexes. 

Macrolabis K. 


I2 8 NORTH AMERICAN DIPTKRA. 

EE. Em podia trifid.* 

9. Antennae composed of twelve joints in both sexes. 

Arnoldia K. 

10. Joints of antennae more numerous in male than in fe- 

male; last abdominal segment not swollen. 

Dryomyia K. 

11. Antennae composed of more than twelve joints; last ab- 

dominal segment swollen ( 9 ) Dasyneura. 
BB. Anterior border of the wings without squamae; claws simple. 
F. Empodia simple. 

12. Palpi with four joints; antennae fourteen-jointed, verti- 

cillate. ...... Schizomyza K. 

13. Palpi four-jointed; antennae fourteen-jointed, not verti- 

cillate Polystepha. 

14. Palpi three-jointed; costa with squamae. Cystiphora K. 

15. Antennas fonrteen-jointed, not verticillate; palpi with 

less than four joints. . . . Asphondylia. 
FF. Empodia trifid; antennae verticillate. 

16. Palpi with one or two joints. . Rhopalomyia R. 

17. Palpi with three joints. . . Oligotrophus L,at. 

18. Palpi with fcnir joints, long. . . . Janetiella K. 

19. The second vein reaches the tip of the wing, palpi with 

four joints. ..... Mayetiola K. 

20. Palpi with four long joints. . . . Mikiola K. 

21. Thorax produced over head. . . Hormomyia. 
BBB. Thorax not prolonged over the head; antennae fourteen-jointed 

in both sexes; in the male each joint of the flagellum with two 
bead-like swellings, giving an appearance of twenty-six joints 
for the antennae. 

G. Claws of front tarsi bifid, or curved at right angle and enlarged 
at extremity; or the empodium trifid. 

22. Empodia trifid Putoniella K. 

23. Verticils of antennae curved and irregular; larvae zo- 

ophagous Bremia Rond. 

24. Verticils regular; all the claws bifid. Dicrodiplosis K. 

25. Verticils regular; hind claws not bifid; larvae mycophag- 

ous Mycodiplosis R. 

26. Claws simple, bent at right angles and dilated below 

near extremity. . . . Octodiplosis ( >iard. 
GG. Claws simple, bent or curved at right angles, but not en- 
larged; em podia simple. 

27. Three-jointed palpi; scales of wings elongated and nar- 

rowed at base Endaphis K. 

28. Second longitudinal vein terminates before the tip of the 

wing; larvae zoophagous. . Arthrocnodax Rbs. 

29. Palpi with a single joint. . Monarthropalpus R. 

30. Palpi two-jointed, the first long and attenuated in the 

middle Massalongla K. 

31. Palpi with three joints; second joint of antennae with a 

tooth Acrodiplosis K. 

* I use this expression, not being certain whether or not the trifid 
character is due to real pulvilli. Kieffer simply begs the question by 
the expression 'pelote unique,' 'pelotes trois'. 


CECIDQMYDI^. 

32. Palpi with three joints; empodia longer than claws. 

Stenodiplosis Rent. 

33. Palpi with four joints; empodia shorter than claws. 

Contarinia R. 

34. Costal vein not interrupted after its junction with third 

longitudinal vein. . . . Thecodiplosis K. 

35. Male antenmG with swellings alternately simple and 

double; ovipositor very long. Xylodiplosis K. 

36. Ovipositor not longer than bod}-; costal vein not inter- 

rupted beyond third vein; empodia one-half the length 
of claws. ...... Loewiola K. 

37. First two joints of flagellnm not fused; empodia nearly 

as long as claws. . . . Macrodiplosis K. 

38. Enlargements of male antennae irregular, alternately 

double and single; empodia longer than claws; first two 
joints of flagellum fused. . . Harmandia K. 

39. Enlargements of male llagellum irregular, alternately 

double and single; empodia shorter than claws; ovipos- 
tor not prominent. . . . Clinodiplosis K. 

40. Wings usually spotted; larvae zoophagous. 

Lestodiplosis K. 

41. Joints of male flpgellum alternately single and double; 

costal vein interrupted after junction with third vein; 

empodia longer than claws. . . . Diplosis. 
BBBB. Anterior cross- vein present and curved, apparently the begin- 
ning of the third vein; the longitudinal always terminate at or 
beyond the tip of the wing. 

42. Three longitudinal veins, the first, third and fifth; an- 

terior transverse not parallel with first vein. 

Bryocrypta K. 

43. Anterior cross-vein curved in form of an S (first joint of 

the tarsi prolonged below at extremity) . Colpodia. 

44. Anterior cross-vein not curved in form of an S; fifth 

vein not furcate; palpi with two joints; claws bifid. 

Colomyia K. 

45. Palpi with four joints; claws simple; empodia simple. 

Holoneurus K. 

46. Fifth vein furcate. ..... Dirhiza. 

47. Flagellar joints petiolate; fifth vein furcate. Epidosis. 

48. Like Epidosis, abdomen slender. Camptomyia K. 

49. Fifth vein furcate at base of wing; claws simple; empo- 

dia simple Ruebsaamenia K. 

50. Like Ruebsaamenia, abdomen not recurved; empodia 

trifid, claws simple. . . . Clinorhytis K. 

51. As in Clinorhvtis\ antennae with more than fourteen 

joints; empodia simple; claws bifid. Asynapta Lw. 

52. Like preceding, claws bifid, empodia simple; antennae 

with fourteen joints. . . . Winnertzia. 

53. Neuration as in Clinorhytis, second vein arises near 

base. Diallactes K. 


NORTH AMERICAN DlPTERA. 


HETEROPEZIN^. 

A A. 54. Two joints in the tarsi, the first shorter than the second; 
no palpi; with two or three longitudinal veins. 

Oligarces Mein. 

55. Tarsi with three joints, the first longest; two longitudinal 

veins ........ Heteropeza. 

56. Tarsi with four joints, first longer than second; three lon- 

gitudinal veins; palpi with two joints. Miastor Mein. 

57. Tarsi with five joints, first shorter than second; wings acu- 

minate at extremity; palpi three-jointed; three longitud- 
inal veins. , ..... Pero Mein. 

58. Like preceding, palpi two-jointed, third longitudinal vein 

evanescent before extremity. . . . Firenia K. 

59. Like Firenia; palpi single jointed. . Leptosyna K. 

60. Tarsi with five joints, the first longer than second; scales 

of wings long and striated. . . Lasiopteryx W. 

61. Like preceding, but tarsi with four joints and neuration as 

in Perrisia. ..... Ledomyia K. 

62. Like Ledomyia, but first joint of tarsi shorter than second; 

fifth vein simple. . . . Brachyneura Rond. 

LESTREMIN^. 

AAA. First joint of tarsi longer than the second; fourth longitudinal 

vein present. 
H. Fourth vein simple; fifth furcate near its middle. 

63. Flagellum in the male with twelve joints, in the female 

with nine; palpi with three or four joints; claws simple. 

Joarmisia K. 

64. Male flagellum with twelve, female with eleven, palpi with 

two joints. ...... Peromyia. 

65. Claws denticulate; no empodia; antennal joints long-petio- 

late. ....... Wasmaniella K. 

66. Claws as in Peromyia; palpi four-jointed; antennae as in 

Pr ion el I its. . . . . Bryomiya K. 

67. Claws denticilate; empodia large; flagellar joints of male 

antennae excentric. .... Prionellus. 

68. Like Prionellus, but the claws not denticulate, and the 

empodia short or rudimentary. . . Aprionus K. 

69. Like Aprionus but the claws denticulated. Monardia K. 

70. Antennae very short, composed of ten or eleven joints in 

the male and from six to eight in the female; joints not 
petiolate in either sex. . . Micromyia R. 

71. Antennae with about twelve flagellar joints in the male, 

from ten to twenty-three in the female. Campylomyza 


VII. FAMILY MYCETOPHILID^S. 


Fig. 39. Sciara, sp. 


Enlarged. 


After Washburn. 


Mostly small, delicate, slender flies, with more or less 
elongated coxae. Head small, rounded or somewhat 
elongate. Eyes round, somewhat prominent; ocelli two 
or three in number, when only two, placed one on each 
orbital margin ; rarely apparently wholly wanting ; when 
three in number, placed transversely in the form of a 
shallow triangle. Front broad in both sexes. Antennae 
elongated, curved, twelve to seventeen-jointed, the two 
basal joints differentiated, the remainder cylindrical, flat- 
tened, or petiolated. Proboscis rarely elongated: palpi 
three or four- jointed, usually inflected, the first joint 
small ; occasionally absent. Thorax more or less, some- 
times highly arched, without transverse suture; metano- 
tum large; scutellum small. Abdomen elongated, com- 
posed of six or seven segments, cylindrical or compressed, 
sometimes narrowed at the base ; male genitalia project- 
ing forceps-like; ovipositor pointed, usually with two 
terminal lamellae. Legs more or less elongated, the coxae 


I <, 2 NORTH AMERICAN DIPTKRA. 

more or less, sometimes much elongated; femora more 
or less dilated, tibiae with spurs. Wings large (wanting 
in the 9 of Epidapus}\ auxiliary vein present, though 
sometimes rudimentary; second longitudinal vein want- 
ing; the third vein arises from the first usually at such 
an angle that its first section (to the anterior cross- vein) 
has the appearance of a cross-vein; fourth vein always, 
the third* and fifth either furcate or not ; sixth vein never 
furcate, sometimes rudimentary; seventh vein usually 
short, often rudimentary or entirely wanting; discal and 
posterior basal cells always wanting. 

The family Mycetophilidae, commonly known as fun- 
gus-gnats, comprises nearly a thousand described species 
of small or minute flies, the best known of which are, 
perhaps, the various dark- winged species of Sciara so 
common about gardens. In the following description of 
the immature stages I draw largely from Osten Sacken. 

The larvae have a distinct horny head; horny, flat, la- 
melliform mandibles; maxillae with a large coriaceous 
inner lobe and a horny outside piece, with a circular in- 
cision at the tip, the labium small, horny, almost rudi- 
mentary; the antennae are usually small or rudimentary, 
the ocelli are Cither wanting or seen in a small pellucid 
spot below each antenna. The body is subcylindrical, 
more or less elongated, fleshy, whitish or yellowish, and 
composed of twelve segments. It is smooth, without 
hairs or bristles, except those on the ventral side. It is 
generally transparent, showing distinctly the intestinal 
canal and the trachea. There are eight pairs of stigmata, 
one on the first segment, and seven on the first seven ab- 
dominal segments, the last two having none. The loco- 
motory organs consist of more or less apparent transverse 

i 

* I am of the opinion that the so-called anterior branch of the third 
vein is in reality a vestige of the second vein. 


MYCETOPHILID^. 

swellings on the underside of the ventral segments, some- 
times furnished with minute bristles or spines. 

The larvae present some of the most singular habits 
among all diptera. They are gregarious, and live in or 
upon decaying matter. Most of the species seem to pre- 
fer fungus or fungoid substances, whence comes the com- 
mon name of fungus-gnats applied to the mature insect. 
The larvae of Sciara are found among decaying leaves, 
in vegetable mold, in cow-dung, under the bark of dead 
trees, etc.; they often live in the soil of potted plants. 
The larvae are said to moult several times before pupat- 
ing. The larvae of many species spin delicate webs over 
the surface cf fungi, and on this web they live until ready 
to pupate, when they spin a dense cocoon in sheltered 
spots; others live within the decaying fungi. Perhaps 
the strangest habits of all are those of species of Sciara, 
which are even more gregarious than other members of 
this family. They have the singular propensity of stick- 
ing together in dense patches, and will form processions 
sometimes twelve or fourteen feet in length, and two or 
three inches broad. The phenomenon has been observed 
frequently both in Europe and America, but the reason 
therefor is not yet well understood, though the object of 
migration seems to be the search for better feeding 
grounds. Because of this habit, the name of 'army worm' 
has been given to them. Yet more singular is the phos- 
phorescent character of the larvae of some species. The 
larvae, probably of Sciophila, were observed by Hudson 
to be so luminous that 'the light of a single individual 
kept in a caterpillar cage may be seen streaming out of 
the ventilators at a distance of several feet.' 

The pupae of Mycetophilidae are free, that is they are 
not contained within the larval skin, as is so commonly 
the case with diptera. They are usually smooth, with 
the legs applied to the breast and venter, the antennae 


134 


NORTH AMERICAN DIPTKRA. 


Fig. 40. Mycetopbilidae. I, Manota dejecta; 2, P) -obolccits singn- 
laris, head; 3. Frobolceus singularis, wing; 4, Macrocera concinna, 
wing; 5, Ceroplatus longimanus, wing; 6, Sciara zygoneura, wing; 
7, Sciara americana, wing; 8, Sciara, sp., antenna; 9, Platynra ig- 
nobilis, wing; 10, Sciophila diluta, wing; n, Neoempheria niaculi- 
pennis, wing; 12, Phthiniafraudulenta, wing; 13, Neoglaphyroptera 
nitens, wing; 14, Plesiastina, sp., wing; 15, Mycetophila insipiens, 
wing; 16, Tetragoneura sylvatica, wing(Wulp); 17, Dynatosoma fus- 
cicornis, wing (Wulp). 

bent around the eyes, and their remaining portion ap- 
plied to the breast between the wings and the legs. The 
pupae of not a few are enclosed in a cocoon of more or 


MYCETOPHILIM. 


135 


less density, spun by the larvae ; others enclose them- 
selves in earthy cases. 

The study of the mature insect requires some care. 
Usually a compound microscope is necessary for the de- 
tection of many characters, especially of the more minute 
species, and generally, when there is doubt of the iden- 
tity, it is best to mount the whole insect or the most im- 
portant paits under a cover glass. 

In America, as elsewhere, but little study has been 
given to this family, and hence there are doubtless not 
a few genera that have hitherto escaped detection. The 
following table has been for the most part compiled from 
V. d. \Vtilp, Winnertz and Schiner, and compared with 
representatives of nearly all the genera. 

TABLE OF GENERA. 

1. Coxae moderately long; anterior cross-vein in the same right line 

with the second section of the third vein; the fifth vein forked 

near base of wing Sciarinse. 

Coxae much elongated; anterior cross-vein distinctly angulated 
from the second section of the third vein. . 2 

2. Only the distal part of the forks of the fourih vein visible. . 3 
Fourth vein visible in its whole extent, the anterior fork rarely in- 
complete proximally. ..... 4 

3. Proboscis short; palpi three-jointed; ocelli distinct (1) . Manota. 
Proboscis much elongated; no palpi; ocelli indistinct or absent 

(2,3) Probolseus. 

4. Origin of fourth vein from the fifth, near base of wing; sixth vein 

more or less indistinct. .... 5 

Origin of fourth vein opposite or beyond the origin of the third; 

sixth vein usually distinct. . 6 

5. Third longitudinal vein furcate, its anterior branch* usually so near 

its origin and so transverse in position that it resembles a super- 
numerary cross-vein; three ocelli present. Sciophilinse. 
Third longitudinal vein not furcate. . . Mycetophilinse. 

* In reality the second longitudinal vein. 


NORTH AMERICAN DIPTKRA. 

6. Third longitudinal vein not furcate. . . . Diadocidia. 
Third longitudinal vein furcate. ...... 7 

7. Anterior branch of third vein long, terminating in the costa. 

Mycetobiinse. 

Anterior branch of the third vein short, more transverse, usually 
ending in the first vein. ....... 8 

8. The praefurca of the fourth vein arises from the third vein beyond 

the anterior cross-vein, i. e. the cross-vein is really wanting and 

the third and fourth veins are coalescent for a short distance. 9 

The fourth vein continuous in nearly the same line from the fork 

to its origin from the fifth; cross-vein distinct. Bolitophila. 

9. Antennae short and thick-set, often flattened. . Ceroplatinse. 
Antennas exceedingly long and slender, longer than the body (4). 

Macrocera. 

SCIOPHILIN^B. 

1. Anterior cross-vein more than twice the length of the basal section 

of the third vein, forming apparently the beginning of the 

third vein (16) Tetragoneura. 

Anterior cross-vein shorter or but little longer than the first sec- 
tion of the third vein, and forming a distinct angle with the 
second section. ......... 2 

2. The costal vein terminates at the tip of the third vein (1O). 

Sciophila. 

The costal vein continues a short distance beyond the tip of the 
third vein. .......... 3 


3. Fork of the fourth vein short petiolate, the prefurca shcrter than 

the anterior cross-vein. . . . Lasiosoma. 

Prefurca of fourth vein much longer than the anterior cross-vein. 4 

4. Proximal end of the posterior furcation (fifth vein) before or op- 

posite the anterior cross-vein (11). . . Neoempheria. 
Proximal end of the posterior furcation beyond the anterior cross- 
vein Polylepta. 

MYCETOBIIN^. 

i. Auxiliary vein complete; the anterior branch of the third vein arises 
at a point where the third vein and the anterior cross-vein unite. 

Mycetobia. 

Auxiliary vein rudimentary, not terminating in the costa; furca- 
tion of third vein petiolate. ...... 2 


MYCETOPHILID.^. I37 

2. Furcation of third vein more proximad than that of the fourth. 

Ditomyia. 
Furcation of fourth vein more proximad than that of the third (14) 

Plesiastina. 


1. Face and proboscis prolonged, snout-iike. . Asindulum. 
Face and proboscis not produced. ...... 2 

2. Antennae shorter than the head and thorax, flattened; palpi short 

(5). ........ Ceroplatus. 

Antennae moie elongate, cylindrical; palpi moderately long (9). 

Platyura. 
MYCETOPHILIN^S. 

1. Three ocelli present. ........ 4 

Two ocelli, one situated near the margin of each eye. . . 2 

2. The costal vein is continued beyond the tip of the third vein. 

Eudicrana. 
The costal vein reaches only to the tip of the third vein. . 3 

3. Auxiliary vein vestigial, projecting only a short distance beyond 

the humeral cross-vein; furcations of fourth and fifth veins near- 

ly opposite each other (15) . . ... Mycetophila. 

Auxiliary vein complete, longer than the humeral cross vein; end- 

ing in first vein (17) ...... Dynatosoma. 

4. Auxiliary vein complete, terminating in the costa. . . 5 
Auxiliary vein not terminating in the costa, rudimentary or ter- 

minating in the first vein. ....... 12 

5. Proboscis much elongated ..... Gnoriste. 
Proboscis short. ..... ... 6 

6. Auxiliary vein connected by a small cross-vein with the first longi- 

tudinal. .......... 7 

Auxiliary vein not connected by a cross-vein with the first longi- 
tudinal. ......... Leia. 

7. Fifth vein furcate. ......... 8 

Fifth vein simple, not furcate. .... Acnemia. 

8. Origin of the third vein perceptibly past the middle of the wing, 

the anterior cross-vein longer than the distal section of the first 
vein (13). . . Neoglaphyroptera. 

Origin of the third vein distinctly before the middle of the wing, 
the anterior cross-vein much shorter than the distal section of 
the first vein. o 


!-^S NORTH AMERICAN DIPTKRA. 

9. Upper branch of the fork of the fourth vein incomplete at the 

base; third vein sinuous ( Odontopoda } . . . Anaclinia. 

Fork of fourth vein complete; third vein not markedly sinuous. 10 

10. Furcation of the fifth vein before or opposite the furcation of the 

fourth. ... ....... ii 

Furcation of the fifth vein distinctly more distal than that of the 
fourth (12) Phthinia. 

11. The costal vein continues beyond the tip of the third vein; abdo- 

men cylindrical. ....... Boletina. 

The costal vein terminates at the tip of the third vein; abdomen 
compressed. ....... Leptomorphus 

12. Auxiliary vein elongated, terminating angularly in the first vein, 

near the origin of the third. .... Syntemna. 

Auxiliary vein vestigial or ending acutely in the first vein before 

the origin of the third. ....... 13 

13. Fifth longitudinal vein not furcate . . . Zygomyia. 
Fifth longitudinal vein furcate. ...... 14 

14. The costal vein extends a little beyond the termination of the 

third vein. .......... 15 

The costal vein terminates at the tip of the third vein. . 17 

15. Forked cell of the fifth vein acute proximally, the branches grad- 

ually and but little divergent Epicypta. 

Forked cell of fifth vein less acute proximally, the branches more 
widely and rapidly divergent, the upper branch curved. 16 

16. Auxiliary vein of considerable length, terminating in the first vein. 

Docosia. 

Auxiliary vein short, ending free a little beyond the humeral cross- 
vein Phronia. 

17. Auxiliary vein reaching beyond middle of first basal cell, and ter- 

minating in first vein. ..... Trichonta. 

Auxiliary vein vestigial, or not reaching as far as the middle of the 
first basal cell. ......... 18 

18. Furcation of the fourth vein before the first section of the third 

vein. ........... 19 

Furcation of fourth vein beyond the first section of the third 
vein. 20 


19. Furcation of fifth vein more distal than that of the fourth. 

Exechia. 
Furcation of the fourth vein more distal than that of the fifth. 

Rhymosia. 

20. Furcation of the fifth vein more distal than the junction of the 

fourth -with the anterior cross-vein. ..... 21 

Furcation of thefifih vein more proximal than the junction of the 
fourth with anterior cross-vein. . . Brachycampta. 

21. Furcation of fifth vein more distal than that of the fourth. 

Mycothera. 
Furcation of fourth vein more distal than that of the fifth. 

Allodia. 


1. Wings and halteres wholly wanting. . . Epidapus 9- 
Wings and halteres as usual. ....... 2 

2. The fourth vein springs from the third at an angle, i. e. the anterior 

cross-vein is obsolete. , Epidapus $ . 

Anterior cross-vein not obsolete. ...... 3 

3. Proboscis much elongated, longer than the thorax. Eugnoriste. 
Proboscis short. ......... 4 

4. Wings very distinctly hairy; claws not denticulate. Trichosia. 
Wings bare or slightly hairy. ....... 5 

5. Antennal joints of male pedicillate and with whorls of hair; forks 

of fourth vein arcuate. ..... Zygoneura. 

Antennal joints not pedicillated, bare or with short hairs. . 6 

6. Claws denticulate. ....... Odontonyx. 

Claws not denticulate. ........ 7 

7. Face strongly produced ...... Rhynchosciara. 

Face not produced. ........ Sciara. 

Additional Generic References. 

Odontonyx Ruebsaamen, Berlin. Ent. Zeit. xxxix, 25, 1894. 
Mexico. 

Rhynchosciara Ruebsaamen, 1. c. Mexico. 


VIII. FAMILY BIBIONID^. 


Fig. 41. Bibio albipennis, enlarged. After Washburii. 

Moderately or very slender flies, of from one to twelve 
millimeters in length. Head usually somewhat flattened; 
front in the male usually very narrow or the eyes con- 
tiguous ; face short; eyes round or reniform ; ocelli large, 
distinct ('absent in Hesperodes' ) . Antennae composed of 
from eight to sixteen joints, cylindrical or a little flat- 
tened, rarely longer than head and thorax, the joints 
usually closely united. Proboscis never much elongated, 
with thickened, hairy labella; palpi variable, three to 
five-jointed, sometimes long, at other times short. Tho- 
rax without suture; scutellum half round. Abdomen 
composed of from seven to nine segments, sometimes 
elongated. Legs moderately long and strong, the hind 
pair more or less elongated, the front femora often thick- 
ened; front tibia often with a stout hook or coronet of 
spines at the tip ; pulvilli and empodium usually distinct, 
but the former in many of the smaller forms wanting. 
Wings large, the anterior veins often stouter than the pos- 
terior ones; costa not extending on the posterior margin ; 

140 


second longitudinal vein wanting, the third arising from 
the first; third vein sometimes furcate;* fourth usually 
furcate ; first basal and often the second basal cells com- 
plete; anal cell rarely closed; posterior cross-vein always 
wanting. 

The relationships of this small family of nematocerous 
flies are very close with the Mycetophilidae through the 
Pachyneurinae and Scatopsinae ; indeed there is greater 
difference between some genera included in the family 
than between the families themselves. One of these 
annectant genera is Hesperodes described a few years ago 
by Coquillett. Because of the presence of a distinct sec- 
ond basal cell, and the resemblance of its venation to 
Hespennus, it would seem better placed here than among 
the Mycetophilidae, where its author placed it. A glance, 
however, at the different types of venation in the figures 
will show how composite a group the family is, as at 
present recognized. 

Such larvae as are known are cylindrical, footless, with 
transverse rows of bristles, usually with eyes; they feed 
upon excrementitious or vegetable substances, especially 
on the roots of grass. The pupae are inactive, for the 
most part free, living in excavated, smooth oval cavities 
near the surface of the ground, which the larvae have 
prepared before undergoing their metamophosis, and 
where the pupae remain before emerging in the perfect 
state. 

In some species the male flies differ very noticeably in 
coloration from the females, so much so that they are 
commonly mistaken for different species. Some of the 
species, especially Bibio albipennis, are very abundant in 
early spring, in meadows, about willows, upon the win- 

'' The anterior branch is in reality the second vein. 
15 


142 


NORTH AMERICAN DIPTKRA. 


clows, etc. They are all rather sluggish in flight, and 
the males are conspicuous because of the very large and 
hairy eyes. Some of the species of Scatopse are very 
minute, among the smallest of all diptera. But very lit- 
tle has been done in the way of critical study of the gen- 
era and species of this family; it is an excellent field for 
research. 


l 3 


'""'' "" ' 


7 


Fig. 42. Bibionidae. i, Plecia, wing; 2, 3, Plecia, antennae; 4, 
Bibio, wing; 5, Bibio, palpus; 6, Bibio, antennae; 7, Scatopse, wing; 
8, AspisteS) wing (Wmp); 7, bis, Scatopse, wing; 7a, Scatopse, last 
tarsal joint with claws and empodium ; 8, bis, Scatopse, wing; Sa, 
Scatopse, head. 


TABLE OF GENERA. 

1. Second basal cell present 

Second basal cell wanting (Scatopsintr} . . 

2. Third longitudinal vein furcate. 
Third vein not furcate. 


2 

7 

3 
5 


3. Palpi four-jointed; antennae slender, more than ten-jointed; slen- 
der species (Pachyneurince} 4 

Palpi five-jointed; antennae eight or nine-jointed; less slender spe- 
cies (1, 2, 3) Plecia, 


4. Antennae twelve-jointed; anterior cross-vein distinct. 

Hesperinus. 

Antennae sixteen-jointed; anterior cross-vein obsolete, that is the 
third and fourth veins are coalescent for a short distance. 

Hesperodes. 

5. Front tibiae with a stout spine-like process at tip, ... 6 

Front tibiae with a coronet of spines; antennae ten or eleven-jointed. 

Dilophus. 

6. Anterior cross-vein distinct; antennae ten-jointed (4, 5, 6) . 

Bibio. 
Anterior cross-vein obsolete; antennae ten-jointed (?) . Bibiodes. 

7. Front tibiae ending in a spine-like process; antennae twelve-jointed. 

(8) Aspistes. 

Front tibiae of the usual structure; antennae nine or ten-jointed (7, 
7 bis. 7a, 8 bis, 8a) Scatopse) . 


IX. FAMILY 


Fig. 43. Siniulinm venustum; enlarged. After Washburn. , 

Small flies, from one to six millimeters in length, with 
thick, short legs. Head hemispherical; face short; 
eyes round or reniform, holoptic in the male; no ocelli.- 
Antennae scarcely longer than the head, flattened or cyl- 
indrical, ten-jointed; the two basal joints differentiated, 
the others closely united. Proboscis not elongated, with 
small, horny labella ; palpi incurvate, four-jointed; the 


first joint short and the two following of equal length; the 
last one longer and more slender than the preceding. 
Thorax arched, without suture; the scutellum small. Ab- 
domen cylindrical, composed of seven or eight segments; 
genitalia concealed ; legs strong and not elongated ; fe- 
mora broad and flat: tibiae usually with terminal spurs ; 
first joint of the tarsi longer than the following and usu- 
ally dilated in the male; the last joint small. Wings 
large and broad, with distinct alulae, anterior veins thick- 
ened, the others slender; auxiliary vein terminating in 
the costa about the middle of the wing; second longi- 
tudinal vein wanting, the first and third lying close to 
each other; the third arising from the first rectangularly 
before the end of the auxiliary vein ; anterior cross-vein 
very short; fourth vein curved, forked nearly opposite 
the anterior cross- vein; the forks terminating near the 
tip of the wing. 


Fig. 44. Sium/iiitn rennstmn, enlarged. After Washburn. 


I4 6 NORTH AMERICAN DIPTERA. 

The family Simuliidae, comprising about seventy-five 
described species, is one of the best known popularly 
among diptera, on account of the troublesome character 
of the flies, which are scarcely less annoying than the 
true mosquitoes; they rarely exceed five or six mm. in 
length, usually not more than three or four, and will be 
immediately distinguished from the mosquitoes by their 
thick-set appearance, their shorter legs, their shorter 
proboscis, and less slender antennae. In the southern 
States they are known as ' buffalo gnats' and 'turkey 
gnats', and sometimes occur in almost incredible num- 
bers ; cattle when attacked by large numbers are driven 
almost frantic, and will seek to evade them by rolling in 
the dust, rushing about, or going into the water. When 
the flies are numerous they will almost literally cover the 
cattle, especially seeking the openings of the body, en- 
tering the nostrils and the ears, the margins of the eyes, 
where they will actually lie piled upon each other. When 
very numerous they will produce an inflammatory fever, 
frequently terminating in death. Infants have been 
known to succumb to their bites. The well known Euro- 
pean species is 5*. columbaczense , w r hich during some sea- 
sons in the regions of the Danube costs the death of many 
cattle. 

The larvae are very interesting creatures; they are 
aquatic, living most frequently in mountain streams, on 
stems of plants, or stones, where they form for themselves 
elongated cocoons, opened above. In the open end of 
these cocoons the pupae ensconce themselves with the an- 
terior part of the body naked and free, from which ex- 
tend eight or sixteen very long, slender, threadlike 
breathing tubes. The perfect insect escapes under water 
and comes to the surface. The larvae are soft-skinned, 
thickened at the extremities, with a cylindrical head, 
two pairs of eye-spots ; on the first thoracic segment there 


SIMULIIDJ6. 


147 


is a foot protuberance with bristly booklets ; and the. end 
of the abdomen has several appendages for attachment. 


Fig. 45. Simuliidae. Simulium, wing; la, Siniuliuni, front tarsus; 

2, genus nov., wing; 2a, id. head, front view; 2b, id. head, side view; 

3, Simuliuin, antenna. 

But a single genus, Simulium, has hitherto been known 
in this family. What seems to be a distinct genus has 
long been known to me in a single imperfect specimen 
from the West Indies. The form will, I hope, be recog- 
nizable from the accompanying illustrations made by me 
many years since. (2, 2a, 2b) . The specimen is exceed- 
ingly minute, and was discovered closely applied to and 
sucking the juices from the antenna of a phasmid. The 
antennae and palpi are mostly wanting in the specimen. 


X. FAMILY 


BY PROF. v. i,. KEXIOGG. 


Fig. 46. Bibiocephala elegantula, enlarged. After Kellogg. 

Moderate-sized, elongate, bare species with long legs 
and broad wings. Eyes usually dichoptic in both sexes, 
but occasionally holoptic in one or both sexes ; eyes of 
both sexes usually bisected by a line or narrow unfacet- 
ted space, with the two fields composed of larger and 
smaller ommatidia (indicated by larger and smaller cor- 
neal facts), in a few species the eyes bisected only in one 

148 


sex. Three ocelli present. Antennae slender with from 
nine to fifteen segments, clothed with short pubescence. 
Mouth-parts elongate, females with slender, flattened, 
elongate, saw-like mandibles, males without mandibles; 
both sexes with slender elongate labrum-epipharynx, 
hypopharynx, and a pair of maxillae with five-segmented 
palpi; labium with a strong, elongate basal sclerite and 
a pair or free, fleshy terminal lobes without pseudo-tra- 
cheae, and with no palpi. Thorax with a distinct, broad- 
ly interrupted transverse suture; legs moderately slender, 
the hind pair much longer than the anterior ones, the 
front femora of males curved in some species, tibiae with 
or without spurs; empodia very small, almost rudimen- 
tary, pulvilli wanting; wings broad, bare, with a mark- 
edly projecting anal angle, and peculiarly different from 
these of all other flies in the possession of a fine spider- 
web like net-work of lines ('secondary venation') which 
are the creases made by the folding of the wings in the 
pupal stage. 

The larvae are curious, flattened, slug-like creatures, 
legless, but provided with six suckers arranged in a me- 
dial longitudinal row on the venter (one sucker for each 
cf the six parts separated by constrictions of the body, 
of which the anterior part is composed of the fused head 
and thoracic segments, and the posterior part of the 
fused last two abdominal segments, the other four 
parts representing each a single abdominal segment). 
The larvae live in swiftly running, shallow, clear and 
highly aerated water (mountain brooks) clinging by the 
suckers to the smooth surface of boulders or the rock bed 
of the stream. The pupae are even more extraordinarily 
shaped, being flat below and flatly convex above with 
strongly chitinized, dorsal body-wall smooth and shining 
black or blackish brown, with a pair of projecting pro- 
thoracic dorsal respiratory horns or 'books', each com- 


150 


NORTH AMERICAN DIPTERA. 


posL-d of four flattened leaves, two of them delicate 
tracheal gills and the other two protecting chitinized 
plates. The pupae are fastened by three pairs of pads on 
the flat venter to the rock-bed or boulders in the swift 
stream and are non mobile. 

The delicate adults are to be found, usually only rare- 
ly, despite the oft-time abundance of larvae and pupae, 
clinging to rocks projecting from the stream or to stream- 
side cliffs or foliage. The females are predaceous and 
may be seen flitting about capturing small flies, especial- 
ly Chironomidae, which they lacerate with their saw-like 
mandibles and knife-like maxillae in order to suck or lap 
up the blood. The males are rarely found. A few spe- 
cies are known as yet only in the larval and pupal stages. 
The egg-laying habits are unknown. 

The family Blepharoceridae was established by L,oe\v 
in 1860 to include a half dozen species, which could not 
well be located in any of the existing families. Since 
that time the number in the family has been increased to 
about twenty known forms included in nine genera, of 
which three genera, represented by eight species, are 
found in the United States. Our species are recorded 


Fig. 47. Blepharoceridae. i, Blepharocera, wing, showing second- 
ary venation (Coinstock) ; 2, Paltostoma schineri, wing; 3, Philorus, 
wing (Kellogg); 4, Bibiocef)hala,\^\\\<^ (Kellogg). 


BLEPHAROCERIM. I5I 

from Canada, New York, Colorado, New Mexico, Idaho, 
Utah and California. The foreign species are found in 
Europe, Asia, South America and certain Mediterranean 
islands. 

The family is readily divisible into two groups, of 
which one, characterized by the absence in its members 
of a short, incomplete vein near the posterior margin of 
the wing, includes six genera, nearly all of which are 
represented by a single species, and none of them occur- 
ring in North America, north of Mexico. The remaining 
known species are grouped according to the latest revis- 
ion of the family (Kellogg, 1903) into three genera rep- 
resented in Europe by about six species and in America 

by eight. 

TABLE OF GENERA. 

1. No incomplete vein running into hind border of the wing (Apisto- 

myia, Corsica; H animator hina, Ceylon; Kelloggina, Brazil; 
Curupira, Brazil; Hapalothri.v, Europe) . Proboscis: elongated; 
hind tibia.- with spurs; eyes entire, not bisected (2). 

Paltostoma. 
An incomplete vein near the posterior margin of the wing. . 2 

2. Second longitudinal vein with an anterior branch; a cross-vein con- 

necting the fourth and fifth veins, that is, the second basal cell 
complete. Anterior branch of second vein and the second and 
third veins all separating at a common point or close together 

(4) . Bibiocephala. 

Second longitudinal vein simple, without branch. . . 3 

3. No cross-vein connecting the fourth and fifth veins, that is, the 

second basal cell incomplete (1) . . . Blepharocera. 

A cross-vein connecting the fourth and fifth veins, the second basal 

cell complete (3). Philorus. 

TABLES OF SPECIES. 

BLEPHAROCERA. 

i. Eyes of female contiguous, of male separated by broad space; length 

not over six millimeters. .... ostensackeni. 

Eyes of both sexes separated by a narrow space; length not less 

than seven millimeters. 2 


152 NORTH AMERICAN DIPTERA. 

2. Ungues slender and rather long tenuipes. 

Ungnes stout and shorter. jordani. 

BIBIOCEPHALA. 

1. Eyes contiguous; anterior branch of second vein running into vein 

near margin of wing ; eyes bisected ; front femora of male 

strongly curved. , grandis. 

Eyes separated by a narrow or broad space, in both males and fe- 
males; fore femora of male straight 2 

2. Eyes in both sexes bisected. ....... 3 

Eyes of male bisected, of female not bisected; anterior branch of 

second vein running into the first very soon, making a triangle 
in which the anterior branch forms the shorter side. doanei. 

3. Eyes of male separated widely; of female narrowly; anterior branch 

of second vein running into first vein very soon, forming a 
nearly equilateral triangle. .... elegantula. 
Eyes of both male ami female separated narrowly; anterior branch 
of second vein running into first aboiit one-third the distance 
from origin of second to tip of first vein. . comstocki. 

PHILORUS. 

Philorus is represented by but two known species in America, viz: 
yosemite and ancilla, and by one species in Europe, bilobata L,oew; of 
the two American forms, P. ancilla has the eyes contiguous (in the 
female at least) , while the eyes of P. yosemite are separated by a broad 
front (in the male at least) . 

PALTOSTOMA. 

Paltostoma is known by a single described species from the West 
Indies, and another from Brazil; one or the other or possibly a third 
is known also from Central America. P. schineri will be recognized 
from the generic characters and the figure. 


XL FAMILY ORPHNEPHILID^. 

Small, obscurely reddish yellow, bare flies of peculiar 
appearance. Head small, round ; holoptic in both sexes; 
ocelli wanting; proboscis short; palpi longer than the 
antennae, five-jointed, the first joint short, the second the 
thickest; antennae situated near the oral margin, appar- 
ently consisting of a small first joint, an oval second 
joint and a terminal arista; the second joint and the arista 
are, however, complex, composed of ten or eleven seg- 
ments, the last of which terminates in a bristle. Thorax 
strongly convex, robust, without transverse suture, some- 
what impressed before the scutellum. Scutellum rather 
large, obtusely three cornered; metanotum arched. Ab- 
domen narrower than the thorax, cylindrical, composed 
of seven segments; male genitalia thick, the basal piece 
swollen, bladder-like; ovipositor with broad, rounded 
lamellae. Legs simple, comparatively short ; coxae not 
elongated; tibiae without spurs; tarsi moderately long; 
the front pair about as long as the tibiae, the penultimate 
joint short; claws small; empodia vestigial. Wings 


Fig. 4S. Wing of Orphnephila. 

longer than the abdomen; auxiliary vein short, termin- 
ating in the costa ; second longitudinal vein sinuous; 


153 


I 5 4 NORTH AMERICAN DIPTERA. 

third and fourth veins not furcate; anal angle rounded; 
basal cell short. 

But three or four species of this singular family are 
known, and of them even, as far as I am aware, the larval 
habits are yet unknown. The known American species 
belong to one genus, Orphnephila Haliday; a second 
genus has been proposed by Mik. The small fly is found 
on the banks of streams. 


XII. FAMILY RHYPHID^). 

Head nearly hemispherical; eyes rounded, holoptic or 
dichoptic in the male ; broadly separated by the front in 
the female; ocelli present. Antennae about as long as 
the thorax, composed of sixteen joints, cylindrical, the 
two basal joints distinctly differentiated; those of the 
flagellum closely united, short-haired, gradually decreas- 
ing in size toward the end. Proboscis moderately prom- 
inent, with small labella ; palpi long, four-jointed; the 
second joint longer and broader than the others. Thorax 
convex, without transverse suture; scutellum semicircu- 
lar, short and broad; metanotum strongly developed. 
Abdomen flattened cylindrical, composed of seven seg- 
ments; genitalia concealed or nearly so. Legs slender, 
without spines; the coxae, especially the front pair, more 
or less elongated; metatarsi elongated; tibiae with or 
without spurs: empodia pad-like, the pulvilli absent. 
Wings large, in rest lying flat upon the abdomen; aux- 
iliary vein present; second and third veins not furcate; 


Fig. 49. Rhyphns. Fig. 50. Olbiogaster. 

discal cell complete (fig. 49^); five posterior cells and 
two complete basal cells present; anal cell not narrowed 
in the margin. 

But very few species of this family are known, belong- 
ing to but three genera. The typical genus Rhyphus con- 


I5 6 NORTH AMERICAN DIPTKRA. 

tains a number of species of wide distribution. The 
genus Olbiogaster is known from two or three species 
hitherto recorded only from Mexico and the West Indies. 
' It differs from Rhyphus in the structure of the head (eyes 
separated by a broad front in both sexes, and occiput but 
very little developed), of the antennae (scapus short, fla- 
gellum of male filiform, etc.), of the thorax and abdo- 
men, as also in the venation.' (Osten Sacken.) 

The larvae of Rhyphus are worm-like, legless, naked, 
more or less transparent, with snake-like movements; 
there are two, short, fleshy points at the posterior end. 
The pupae are free, inactive, with two projections ante- 
riorly; they live in water of brooks, pools or puddles, or 
in rotting wood, hollow 7 trees, or manure. 


XIII. FAMILY 


Fig. 51. Lefilis tnystacea, enlarged. After Washburn. 

Species of moderate or large size, more or less elonga- 
ted, usually thinly pilose or nearly bare, without distinct 
bristles. Males holoptic or dichoptic. Empodium de- 
veloped pulvillifonri*, the pulvilli present (figure 14). 
Squamae small or rudimentary. Antennae very variable: 
( i ) the flagellar joints distinct, as many as thirty in 
number (20); (2) the segments not more than eight in 
number, more closely applied, without style or arista 
(13); (3) fewer in number, with a differentiated, seg- 

* Hilarimorpha, (1, 2), which is included in this family by most 
writers, has vestigial empodia and no discal cell. The tibial spurs, also, 

are very small. 

157 


153 


NORTH AMERICAN DIPTERA. 


mented style or arista, altogether not more than eight 
(19); (4) the third joint simple, with or without a ter- 
minal or dorsal arista (7, 9). Veins of the wings distinct, 
not crowded anteriorly; third longitudinal vein furcate; 
basal cells large; five posterior cells usually present. 

As defined above, this family includes the Xylophagi- 
dae, L,eptidae and Coenomyidse of authors. It may be a 
question whether this union is justifiable, but, on the 
whole, it seems that the sole character which can be used 
to distinguish the families the structure of the third 
antennal joint divides the group unnaturally, throwing 
with the Xylophagidae forms whose affinities are great- 
est with the lyeptidae, notwithstanding the antennal char- 
acter. 

The Xylophaginae include less than one hundred 
known forms, and many of them are remarkable for their 
general resemblance to certain hymenopterous insects. 
Species of Rhachiccnis form a connecting link with the 
Nemocera, and are apt to be confounded with the Rhyph- 
idse, but the presence of the pulvilli will distinguish 
them. 

The larvae are found in decaying wood or under the 
bark of trees and are carnivorous and predaceous, feed- 
ing upon the larvae of beetles and other wood insects. 
The skin is parchment-like, the body cylindrical. The 
mouth-parts and antennae are very small, the maxillae 
short and hook-like. The first cr the first three segments 
back of the head are chitinized above; the last segment 
above with a chitinized plate terminating posteriorly in 
two hooks. The fourth to the ninth segments have bristly 
pseudopods below. The pupae are free. Larvae of Xylo- 
mvia have been observed under the bark of fallen cotton- 
wood trees. 

The Leptinae comprise something over two hundred 
known species. They are usually of moderate size and 


LEPTID.^. 


159 


not very active in their habits. The larger species are 
commonly found in meadows and woodlands, resting 
upon stems or trunks of trees with their head downward. 


*' 


\ 


Fig. 52. Ccenomyiaferruginea, female; enlarged. 

They are sometimes predaceous upon other insects, and 
the species of Symphoromyia have a habit of sucking 
blood as do the horseflies. The larvae are predaceous, 
living in the earth, in decaying wood or in passages 
made by woodboring beetles. Others live in moss, in 
sand cr in water. In general they are cylindrical, with 
or without fleshy abdominal legs. The last segment has 
a transverse cleft, the portion above which is provided 
with two, often backward-bent points or processes; the 
under part is obtuse, with the two stigmata between them. 


i6o 


NORTH AMERICAN DIPTERA. 


The eggs of Atherix are depOvSited in dense masses at- 
tached to dry branches overhanging water. Not only do 
numerous females contribute to the formation of these 
masses, but they remain there themselves and die. The 
larvae hatching, escape into the water. The flies of spe- 
cies of Vermileo deposit their eggs in sand, and the larvse 
form conical pitfalls in which to ensnare small insects. 
The tenth segment of these larvse bears above at its tip a 
transverse row of long booklets directed backward, but 
with the hooks bent forward; the eleventh segment has 
a similar row directed for\vard, the hooks of which are 


Fig. 53. Leptidae. i, Ilihiriinorpha, wing; 2, Hilarimorpha, an- 
tenna; 3, Coenomyia. wing; 4, Coenomyia, antenna; 5, Phenens, 
antenna; 6, Chrysopila, wing; 7, Chrysopila, antenna; 8, Symphoro- 
ntyia. head; 9, Atheri.v, antenna; 10, Ptiolina, antenna (Becker); 
n, Spania, antenna (Becker); 12, Xylophagus, wing; 13, Xylofihagiis, 
antenna; 14, Dialysis, tarsus; 15, Dialysis, antenna; 16, Glutops (type) 
antenna (Burgess); 17, Xy/oinyia, antenna. 


161 


turned backward. On the fifth segment below there is a 
simple unpaired grasping foot which is capable of being 
protruded forward and downward; at its tip there are 
t\vo triangular, sharp, flat, chitinous hooks, and below 
them some stiff bristles. The booklets serve as aids in 
boring in the sand and to fix themselves; the organ 011 
the fifth segment assists the larva in seizing and holding 
its prey, and also in constructing the pitfalls. 


21 


Fig. 54. Leptidse. 18. Arthroceras (type) , wing; 19, Arthrocei as 
(type 1 ), antenna; 20, Rhachicerns, head; 21, Athcri.v, venation. 


NORTH AMERICAN DIPTERA. 


TABLE OP GENERA. 

i. Flagelhim of antennae composed of numerous, more or less distinct 
divisions; the antennae more or less elongated; five posterior 
cells present in all cases. ....... 2 

Antennas short, or but little elongated, the third joint simple, with 
a terminal or dorsal arista or terminal style; face small, usually 
excavated; proboscis short; some or all the tibiae spurred (Lep- 
........... 8 


2. All the tibiae with spurs (Xylophagintz] . .... 3 
Front tibiae without spurs (Arthroceratince} . ... 6 

XYLOPHAGIN^. 

3. All four posterior veins (i. e. the veins separating the posterior 

cells) arise from the discal cell; head small, scutellum with two 
spinous protiiberances (Ccenomyintz) (fiig. 52, 3, 4). 

Ccenomyia. 

The last posterior vein arises from the second basal cell, the fifth 
posterior cell hence not at all contiguous with the discal cell; 
scutellum without spines. ....... 4 

4. Flagellum of antennae aciite at tip, eight-jointed; tibial spurs 1:2:2. 

Arthropeas. 
Flagellum of antennae not acute at tip. ..... 5 

5. Fourth posterior cell closed; flagellum of antennae much elongated, 

composed of numerous (twenty-thirty) distinct divisions, often 
pectinate; eyes emarginate near the antennae (20) (Rhnchice- 
riiuf. ........ Rhachicerus. 

Fourth posterior cell open; flagellum composed of eight segments, 
less distinctly separated and never pectinate (12, 13). 

Xylophagus. 

ARTHROCERATIN^:. 

6. Fourth posterior cell open, ....... 7 

Fourth posterior cell closed (17, and 7, 8 Stratiomyidez] . 

Xylomyia. 

7. Face projecting on each side in a rounded, subconical protuberance, 

thickly covered with hair (16) . . . . , Glutops. 

Face with two, deep, diverging fiirrows, running from base of an- 

tennae to oral margin (18, 19) , . Arthroceras. 


8. Front tibiae without terminal spurs. ..... 10 

Front tibiae with a single terminal spur; hind tibiae with two. 9 
Front tibiae with two terminal spurs; hind tibiae with two. 

Triptotricha. 

9. Antennal style slender and jointed; fourth posterior cell closed (5) . 

Pheneus. 

Terminal arista not jointed; fourth posterior cell sometimes want- 
ing (14, 15). ... . Dialysis. 

10. Discal cell wanting; four posterior cells only (1, 2). 

Hilarimorpha. 
Discal cell present; five posterior cells. n 

n. Third joint of the antennae round, oval or pointed. . . 13 
Third joint of the antennae kidney-shaped, with a dorsal or sub- 
dorsal arista. . . . . . . . . . 12 

12. Hind tibiae with a single spur; anal cell open; first antennal joint 

elongate and thickened (8). . . . Symphoromyia. 

Hind tibiae with two spurs; anal cell closed; first antennal joint 

not elongate and thickened (9,21). . . . Atherix. 


13. Hind tibiae with two spurs; anal cell open (fig. 51). Leptis. 
Hind tibiae with a single spur; anal cell closed. ... 14 

14. Third antennal joint onion-shaped or conical, with a slender, arcu- 

ate, terminal bristle (6, 7) Chrysopila. 

Third antennal joint elongate; not with a slender terminal 
bristle. .......... 15 

15. Third antennal joint with a short terminal style (1O) . Ptiolina. 
Third antennal joint emarginate above, pointed, without style (11) . 

Spania. 

Bolbomyia. 'More or less related to Rupellia, and may be placed 
among the Xylophagidae, its somewhat aberrant venation notwith- 
standing. Characteristic is the shape of the antennae; the third joint 
consists of four or five divisions, the first of which is much larger and 
swollen'. L,oew. B. nana, District of Columbia. Length about three 
millimeters. This species has not been recognized since its descrip- 
tion, nor the genus. Possibly it belongs to the There vidae. 


XIV. FAMILY STRATIOMYID^. 

Small to moderately large, nearly bare or thinly pilose, 
bristleless species. Head short, hemispherical or flat- 
tened, as broad as the thorax. Ocelli present. Eyes 
contiguous or separated by the front in the male. Anten- 
nae porrect, approximated at the base, three-jointed, the 
third joint always complex, usually with a terminal style 
or an arista. Proboscis never elongated; palpi two-joint- 
ed, sometimes rudimentary. Thorax never strongly con- 
vex; scutellum often with tubercles, spines or projections 
on its margin, perhaps more exaggerated here than 
among any other group of flies (see fig. 65,86). Abdomen 
composed of from five to seven segments, usually flat- 
tened, often elongated. Legs never thickly pilose; with- 
out bristles, the tibiae without spurs*; pulvilli and empo- 
dia pad-like. The costal vein does not reach beyond tip 
of the wing; veins often crowded anteriorly, and those 
posteriorly weak; discal cell present; four or five poste- 
rior cells, and one or two submarginal cells present, the 
anterior branch of the third vein short and often indistinct 
or wanting. 

The family Stratiomyidse is one of considerable size, 
including about a thousand known species. The flies 
are invariably flower insects, seldom with any marked 
powers of flight and never having the habit cf hovering 
in the air. Not a few species are caught in the beating net 
or on the windows of dwelling houses. Many of the 

* Xylotnyia (7, 8) which Osten Sacken and Austen insist belongs in 
this family, has spurs on the middle and hind tibiae and the costal vein 
encompasses the wing. 

164 


Fig. 55 


Fig. 55. Chrysochlora. Fig. 56. Rhaphiocoa. 

Fig. 57. Ptecticus. 


STRATIOMYID.E. 


165 


species have in life bright yellow or green markings. 
The eggs, such as have been observed, are laid on the 
ground, on plants about water, or perhaps on the surface 
of the water itself. The larvae are carnivorous, or feed 
upon decaying vegetable material. The larvae of Myio- 
chrvsa have been found in cow-dung, and under stones; 

those of Geosargus in the 
flowing sap of elm trees; 
those of Hcrmctia in priv- 
ies ; those of Pachygaster 
and Zabrachia in decaying 
wood; those of B eris in 
moss ; those of Stratiomyia , 
Odontomyia, Nemotelus, 
etc., in water. The larvse 
of Stratiomyia have been 
observed in salt and alka- 
line water. 

The body is smooth and 
flattened, the last segment 
often prolonged into an 
elongated breathing tube 
and having a terminal 
transverse cleft. The pu- 
pae are inactive, develop- 
ing within the larval skin, 
the pupal skin remaining 
within, or partially within, 
the larval skin when the 
fly escapes through a 
longitudinal or trans- 
verse rent. 


Fig-. 58. Cyphomyia; 

female, enlarged. 


166 


NORTH AMERICAN DIPTERA. 


Fig. 59- Stratiomyidse. (See next page.) 


STRATIOMYID^E. 


167 


Figs. 59, 60. Stratiomyidae. i, (Jhiromyza, wing; 2, Beris, wing; 
3, Lleris, antennae; 4, Cynipimorpha, scutellum; 5, Cynipimorpha, 
wing; 6, Acauthhia, wing; 7, Xyloinyia, wing; 8, Xylomyia, antenna; 
9, Hernietia, wing; 10, Hertnetia, antenna; n, Odontomyia, wing; 
12, Odontomyia, antenna; 13, Stratioinyici, antenna; 14, Geosargus, 
wing; 15, Ptecticus, wing: 16, Ptecticus, antenna; 17, Cyphomyia^ an- 
tenna; 18, Merosargns, antenna; 19, Histiodronia, wing; 20, Eupa- 
rhvphus, wing; 21, Euparhyphus, antenna; 22, Enryneur a, \\zdAlrQ\\\ 
in front; 23. Pelagomyia* head; 24, Xeuwielus, head; 25 Aochle- 
tns, antenna ; 26, Analcocerus, wing ; 27, Pachygaster, head ; 28, 
Scoliopelta (type), head; 29 Microchrysa, wing; 30, Clitellaria, head; 
31, Rhaphiocera, wing; 32, My.rosargus, head; 33, Allognosta, wing; 
34, f'hrysoi/ilora, antenna; 35, Khingiopsis, head; 36, l^icranophora. 


NORTH AMERICAN DIPTERA. 


TABLE OF GENERA. 

1. Abdomen with seven visible segments.. .... 5 

Abdomen with five or six visible segments. .... 2 

2. Three posterior veins, .ill arising from the discal cell. . . 38 
Four posterior veins, the first and third sometimes vestigial but 

at least represented by angulations of the discal cell. . 3 

3. All the posterior veins arise from the discal cell, the fifth posterior 

cell hence contiguous proximally with the discal cell. . 29 
The last posterior vein arises from the second basal cell. . 4 

4. Antennae with an elongate terminal or dorsal arista. . . n 
Third antennal joint not with a distinctly differentiated arista, its 

segments homologous or nearly so. ..... 20 


5. Three posterior veins, all arising from the discal cell.* . 6 
Four posterior veins, or vestiges of them, all arising from the dis- 

cal cell; scntellnm with spines. ...... 10 

6. Scutellum with spines. ....... 8 

Scutellnm without spines. ....... 7 

7. Short, small species; third vein with an anterior branch (33). 

Allognosta. 

More elongate and larger species, especially in the female; third 
vein simple (1). . ... . . . Chiromyza. 

8. Scntellnm with ten spines. .... Heteracantha. 
Scutellum with less than ten spines. ..... 9 

9. Head hemispherical (2, 3) ....... Beris. 

Head not hemispherical; the antennas situated low down, the 

frontal region long and plane. .... Berismyia. 

10. Hind femora thickened. ..... Neoexaireta. 

Hind tibiae thickened at extremity.! .... Actina. 

; " The third vein rarely arises from the basal cell in species of Beris. 

t The genus Actina, to which Heris viridis has been referred, has a 
dichoptic head in the male, four posterior veins arising from the dis- 
cal cell, thickened distal extremity of the tibiae, etc. Osten Sacken 
has given as the chief distinction of the genns from Bens the well- 
developed palpi, vestigial in liens. In onr species of Beris, how- 
ever, the palpi are of considerable size. Beris viridis differs from 
other species of the germs in having dichoptic eyes in the male; but 
its venation is typically that of Beris. 


STRATIOMYID^. 


SARGIN^S. 

11. Scutellum with spines. ........ 12 

Scutellum without spines. ....... 14 

12. Third vein with anterior branch (fig. 54; 31). Rhaphiocera. 
Third vein without anterior branch. ..... 13 

13. Scutellum produced into a stout median process, bearing two di- 

varicate spines at its tip (36). Dicranophora, S. A. 
Scutellum with marginal spines. . . . Nothomyia. 

14. Second longitudinal vein coalescent with the first in a broad ex- 

pansion of the costa; antennae moderately long, the long arista 
flattened (19) ....... Histiodroma. 

Wings not with an anterior distal expansion of the costa. . 15 

15. Anterior ocellus more widely separated than the other two; males 

holoptic or dichoptic. ....... 16 

Ocelli equidistant, more approximate. . . . . . 17 

16. Abdomen contracted at its base, clavate or pedicillate 

Macrosargus*. 
Abdomen not clavate or pedicillate (14) (Sargus] . .Geosargus. 

17. Second antennal joint prolonged on the inner side, closely over- 

lying the third joint (fig. 56, 15, 16) . . Ptecticus. 
Second antennal joint not with such a projection. . . 18 

18. Third joint of antennae elongate, composed of four segments, with 

a long terminal arista thickened and pubescent at its base. 

Acrochaeta. 

Third antennal joint short, oval or sxibulate, with an apical or pre- 
apical arista. . . . . . . . . . 19 

19. Hind femora moderately thickened at base; non-metallic, more or 

less yellow species (18). .... Merosargus. 
Hind femora not more thickened at base; usually blue, green and 

metallic species, elongate. . . . Chrysochroma. 

Hind femora slender; small, deep-colored species; the holoptic eyes 

of the male with an area of enlarged facets above; eyes hairy 

(Myiochrysa)', or bare (29). . . . Microchrysa. 

STRATIOMYIN^;. 

20. Third vein with an anterior branch. ..... 21 

Third vein without anterior branch; scutellum spinose. . 28 

* The genus Macrosargus is so feebly differentiated that I do not 
think it can be maintained. If not, the name must take preference 
over Geosargus Bezzi, substituted for Sargus, preoccupied. 


170 


NORTH AMKRICAX DIITERA. 


21. Scutellum without spines; first two joints of antennae short. 

Chordonota. 
Scutellum with spines, rarely absent in species of Odontoinvia. 22 

22. Costa thickened distally in front; antennae elongate, the flagelhmi 

composed of six closely united segments (26). Analcocerus. 
Costa not thickened distally in front. ..... 23 

23. Third antennal joint composed of four, five or six closely united 

segments. .......... 24 

Third antenna! joint composed of seven or eight closely united 
segments. .......... 26 

24. Head strongly produced forward for insertion of the antennae, the 

face nmch retreating (/^roineraiiisa, S. A.) 
Head not strongly prodiiced forward. ..... 25 

25. First antennal joint three or more times the length of the second 

(13). . . . . . . . . Stratiomyia. 

First antennal joint less than three times the length of the second 
(11,12). Odontomyia. 

26. First antennal joint two or three times the length of the second, 

the third much elongated, ...... 27 

First antennal joint but little longer than the second, the third 
terminating in a bristle. .... Neorondania. 

27. Thorax narrowed anteriorly; body with green and yellow mark- 

ings Campeprosopa. 

Thorax not narrowed in front; body black, not with green and 
yellow markings; posterior orbits of female often conspicuously 
tumid and colored (fig. 58; 17). . . . Cyphomyia, 

28. Head strongly produced anteriorly, with a porrect spine immedi- 

ately below the insertion of antennae {Rhingiopsis, S. A. 35.) 
Head not projecting, the face produced conically downward; third 
joint of antennae composed of six* segments (32). 

Myxosargus. 
CLITELLARIN^E. 

29. Scutellum with spines. ........ 30 

Scutellum without spines. ....... 35 

'- The genus Afy.vosargits was described by Brauer as having eight 
segments in the third joint of the antennae, the segments distinguish- 
able with difficulty. The species referred by me to this genus 
have but six segments in the third joint, easily distinguishable. The 
posterior orbits of the female are thin and expanded, and the females 
of all the species have one or more conspicuous tubercles on the front. 


STRATIOMYID^. I7I 

30. Antennae short, with a subterminal arista. . . Oxycera. 
Antennae more or less elongate. ...... 31 

31. Antennae situated near the oral margin, third joint composed of 

five or six segments (22) ... . Euryneura. 

Antennae situated near middle of head in profile. . . 32 

32. Antennae much elongated; style not differentiated; eyes bare; 

smaller species (2O, 21) Euparhyphus. 

Antennae moderately elongated. ...... 33 

33. Style of antennae not differentiated; eyes pubescent; occiput flat- 

tened (28). . . . Scoliopelta. 

Style of antennae distinctly differentiated. . . .34 

34. Eyes pubescent; antennae with a slender style (3O). Clitellaria. 
Eyes bare; style not slender (25). . . . Aochletus. 

35. Face produced conically. ...... 36 

Face not produced. ........ 37 

36. Males holoptic (24 1 ). ... . Nemotelus. 
Males dichoptic. ........ Alisonia. 

37. The third antennal joint terminates in a very long, densely fringed, 

lamelliform style; large, elongate species; eyes pubescent or 
bare ( 9, 1O ) Hermetia. 

Third joint of antennae with a short, thickset, differentiated style 
terminating in a short bristle ; eyes pubescent ; moderate sized 
species (23) Pelagomyia. 

The third antennal joint tapers into a long, thickened, or styliform 
arista, the basal two-thirds of which is short but densely plu- 
mose, the distal extremity bristly; eyes bare (Cacosis, S. A.). 

The third antennal joint terminates in a long slender arista, not 
at all pubescent or hairy at base; eyes bare, large species (fig. 
55:34) Chrysochlora 

PACHYGASTRIN^:. 

38. Antennae sitiiated near or toward the oral margin; scutellum spin- 

ose; males holoptic; eyes pubescent. .... 39 
Antennae situated near the middle of the head in profile. . 43 

39. Third joint of antennae forked; scutellum quadrispinose. . 42 
Third joint of antennae not forked. ..... 40 

40. Third joint of antennae elongate, with a short, differentiated style; 

scutellum quadrispinose (6). .... Acanthina. 
Third joint of antennae shorter; ending in a bristle. . . 41 


j-2 NORTH AMERICAN DIPTERA. 

41. Third joint antennae oblong, with its apex attenuated, the arista 

bare; scntelhim bispinose (Spyridopa, S. A.). 
Third joint snbglobose; scntelhim bispinose (Panacris, S. A.) 

42. Upper branch of antennae with a terminal arista and a lateral pro- 

cess. ........ Neochauna. 

Upper branch with a short, slender style and no lateral process 
(Blastocera, S. A.). 

43. The scntelhim terminates in a stout median spine or process (4, 5) 

Cynipimorpha. 
Scntelhim without median spine or process, simple. . . 44 

44. Third vein with an anterior branch. ..... 45 

Third vein without branch. , Zabrachia. 

45. Third antennal joint oval, with its terminal arista briefly but 

densely plumose. ...... Lophoteles. 

Third joint rounded or oval, its terminal arista bare (27). 

Pachygaster. 

The relationships of the genera allied to Sargus(Geosargus} IWero- 
sargus, Macrosargus (Pedicella Bigot), Chrysochroina, JMicrochrysa 
and Myiochrysa, are all more or less doubtful. Even Ptecticus can 
not be sharply limited by the structure of the second antennal joint. 
I suspect that Pedicella will have to take precedence over Sargiis', 
Macrosargus and Geosargus,.Sind that Chrysochroma will have to be 
merged into Merosargus. The whole group sadly needs revision. 
The: genus Notliomyia, which I do not know, may perhaps find its 
proper place under 28. 


XV, FAMILY ACANTHOMERID^. 


Fig. 61. Acanthoniera sp., 9' Venezuela; natural size. 

Very large, stout, bristleless, nearly bare flies. Eyes 
large, contiguous in the male. Ocelli present. Third 
joint of the antennae complex, composed of seven seg- 
ments, with a terminal, often in the male setiform style. 
Proboscis short, not adapted for piercing, with fleshy la- 
bella ; palpi two-jointed. Squamae rudimentary. Tibiae 
without ^spurs ; pulvilli and empodia pad-like. Wings 
with two submarginal and five posterior cells, the fourth 
posterior cell and the anal cell closed. 

But two genera are known in this family, including al- 
together only about fifteen or sixteen species, all of w r hich 
are inhabitants of Central and South America. The spe- 
cies of Acanthomera are found in forests, alighting on 
trunks of trees, according to Mr. Champion; otherwise 
their habits, \vhether of the adult or immature stages, 
are but little known. Brauer has figured and described 
the larvae of A. frauenfeldii. They are cylindrical, thick 
and short. The last segment is firmly chitinized above 


NORTH AMERICAN DIPTERA. 

with two series of booklets, the two projecting backward 
in the middle being stout and curved; below these there 
is a deep, transverse cleft, on the under side of which is 
a rounded lip. 


Fig. 62. Acanthomera, sp. wing. 

In both Acanthomera and Rhaphiorhynchus the face 
may be produced conically or not at all. The two genera 
are distinguished by the structure of the second joint of 
the palpi, in Acanthomera slender, in Rhaphiorhynchus 
stout and pointed. Both genera may have a spine on 
the under side of the hind femora. 

Osten Sacken has already commented upon the sup- 
posed distinctions between Acanthomera and Rhaphio- 
rhynchus, making it clear that only the palpal character 
is of service, and even that is doubtful since it may be 
only sexual. I have examined five or six species of the 
family and am very skeptical of the validity of Rliapliio- 
rhynchus. 

There are apparently no valid nor just reasons for the 
retention of the generic name Acanthomera. Wiedemann 
more than once, arbitrarily and without giving reasons, 
rejected the earlier names of genera and species for ones 
of his own creation, and the present seems to be one of 
the most flagrant examples. The description and figure 


ACANTHOMERID.^. 


175 


of Pantophthalmus tabaninus Thunberg leave no doubt 
of the form to which they apply, and the description was 
published two years earlier than that of Acanthomera, and 
was quoted by Wiedemann. Possibly Wiedemann thought 
the name inappropriate, but, to say the least, it is no 
more inappropriate than his Acanthomera, in which the 
'spiny femora' may be only an individual character, cer- 
tainly not generic. 

The relationships of the family are very close indeed 
to the Stratiomyidse, and the families might, very prop- 
erly, be united. 


XVI. FAMILY TABANID^, 


BY PROF. J. S. HINE. 


Fig. 63. Tabanns lineola; enlarged. After Lugger. 

Head large, the occiput flattened or concave. Antennae 
porrect, the third joint composed of from four to eight 
segments or annuli. Eyes large, pubescent or bare, con- 
tiguous above in the male, and often with some of the 
facets much larger than the others; in the living insect 
of either sex usually with green or purple bands or spots. 
Ocelli present or absent. Proboscis projecting, some- 
times as long as or longer than the body ; palpi two-joint- 
ed, that is with one movably articulated joint, which is 
variable in length and thickness in different genera. 
Thorax and abdomen clothed with fine hairs, never with 
bristles. Abdomen broad, never constricted at the base, 
composed of seven visible segments; genitalia never 
prominent. Legs moderately stout, the tibiae sometimes 
much dilated ; middle tibiae always with two spurs at 
tip; empodium developed pulvilliform, the pulvilli al- 
ways present. Wings but little variable; two submar- 

176 


TABANID^. 


177 


ginal and five posterior cells always present ; basal cells 
large, anal cell usually closed, but never far before the 
border of the wing; the marginal vein encompasses the 
entire wing. Squamae of considerable size. Flies of mod- 
erate or large size, never slender; rarely with brilliant 
colors. 


Fig. 64. Pangonia guttata; enlarged. 

This family includes the insects commonl}' called horse- 
flies, green-headed flies, etc., and has a wide distribution 
over the world. About eighteen hundred species have 
received names, of which not less than two hundred and 
seventy-five are from North America. None of the spe- 
cies are active on dark, cloudy days, though some are 
partial to shad}- woods, and are very annoying to stock 
in such places. On clear, warm days, horseflies begin 
flying as soon as the sun has warmed the air, and are 
1 8 


178 NORTH AMERICAN DIPTERA. 

usually most active toward the latter part of the fore- 
noon, although they are plentiful about cattle and horses 
during most of the time while the sun is shining. The 
females only are bloodsucking in habit; the males feed 
upon the juices of plants, the honey-dew secreted by 
plant-lice and scale insects, and similar substances. 
The females also will feed as the males do, when nothing 
more to their liking is procurable. Their bites are pain- 
ful, but are not usually attended with that inflammation 
or swelling characteristic of the mosquitoes and punkies. 

Most species of Tabanidae may be collected in various 
situations. Sweeping the grasses and weeds of marshy 
places, collecting from fences and trunks of trees in the 
early morning, or from plants much infested by plant- 
lice or certain scale insects throughout the day, netting 
specimens that fly about stock or the collector's own 
head, or that may be found upon various flowers, or cap- 
turing such as may enter the doors and alight upon the 
windows, all are productive of results. Collections made 
in these ways are prett}^ sure to represent well the tabanid 
fauna of any locality. 

The eggs of the Tabanidse are deposited in large masses 
on the stems and leaves of plants or in similar places 
over water or in marshy land. They are spindle-shaped, 
brown or black in color, and, in ordinary summer temp- 
erature, hatch in from seven to nine days The larvae 
feed upon various small creatures, and in such cases as 
have been observed reach maturity and change to pupae 
the following spring. The pupal stage is completed in 
three or four weeks, the whole cycle from the deposition 
of the eggs to imaginal maturity thus requiring about 
eleven months for its completion. The larvae may be 
sought for in rotting logs and stumps, in the soil in the 
vicinity of ponds, under stones about ditches, or swim- 


TABANID^. 


179 


ming free in the water; indeed one may occasionally find 
them in the most unexpected places. The pupae are 
difficult to find in nature, though they usually rest near 
the surface of the ground wherever the larvae come to 
maturity. Larvae taken in the spring are easily reared 
in jars of moist earth on a diet of angle worms; but only 
a single specimen can be reared in each jar, for they are 
cannibalistic in nature. The body of the larvae is eleven- 
segmented, each segment usually encircled by a row of 
fleshy protuberances, which are most pronounced on the 


Fig. 65. Tabanidae. i, Tabanus, wing; 2, 3, Tabanus, antennae, 
4, Dichelacera, antenna; 5, Snowiellus, head, side; 6, Hcrmatopota 
head, in front; 7, Diachlorus, head, front; 9, Lepidoselaga, front leg; 
iQ,Stibasoma,\eg\ n, Chrysops, head; 12, Chrysops, leg; 13, Goniops, 
head, front; 14, Silvius, antenna; 15, Apatolestes, head, front; 16, Pity- 
ocera, antenna (Giglio-Tos) . Figures by J. S. Hine. 


NORTH AMERICAN DIPTERA. 

ventral side, where they serve as prolegs. The head is 
small, but distinct, and the mouth-parts are peculiar; 
the mandibles are two strongly chitinized pieces which 
work antero-posteriorly ; when they are retracted the an- 
terior ends point directly forward, but when protruded, 
they point downward and backward, thus forming a pair 
of hooks by which the prey is held. 

TABLE OF GENERA. 

1. Hind tibiae with spurs at tip. ....... 2 

Hind tibiae without spurs at tip. ...... 8 

2. First six segments of the third joint of antennae each produced 

into a pair of long processes (16) .... Pityocera. 
None of the segments of third joint of antennae produced into lat- 
eral processes. ......... 3 

3. Third joint of antennae composed of five segments, the first of 

which is much longer than the following ones; ocelli present. 4 

Third joint of antennae composed of eight segments, the first of 

which is only slightly longer than the following ones. . 5 

4. Second joint of antennae only half as long as the first (14) . 

Silvius. 

Second joint of antennae distinctly more than half as long as the 
first (11,12) Chrysops. 

5. Fourth posterior cell of wing closed (Dielisa}. . . Scione. 
Fourth posterior cell open. ....... 6 

6. Eyes of female acutely angulated above; wings in both sexes dark 

on anterior part, hyaline behind (13). . . Goniops. 

Eyes of female not acutely angulated above; wings nearly uniform 

in color or hyaline. ........ 7 

7. Front of female wide; much wider below than above; proboscis 

only a little longer than the palpi (15). . Apatolestes. 

Front of female of normal width or narrow; its sides usually par- 
allel; ocelli present or absent; proboscis often long or very long. 

Pangonia. 

8. Third joint of antennae composed of four segments; front of female 

very wide (6) Hamatopota. 

Third joint of antennae composed of five rings or segments; front 
of female not unusually wide. ...... 9 


9. Third joint of antennae with a distinct basal angle or process 
above. .......... n 

Third joint of antennas not with a process or distinct angle 
above. .......... 10 

10. Front of female narrow; front tibiae rather broad (7) . 

Diachlorus. 

Front of female of normal width; front and middle tibiae greatly 
dilated (9) Lepidoselaga. 

11. Hind tibiae ciliate with long hairs. ..... 12 

Hind tibiae not ciliated. ....... 13 

12. Third antennal joint with a very long basal process, the annulate 

portion short; front tibiae dilated (1O). . . Stibasoma. 

Third antennal joint with a basal prominence; antennae situated 

on a projecting prominence (5). . . . Snowiellus. 

13. Basal process of third antennal joint unusually long, at least reach- 

ing the third ring of the joint; body long (4) Dichelacera. 

Basal process of third joint often short or obsolete, at most not 

reaching the end of the first segment (2, 3). . Tabanus. 

A. Eyes pubescent; an ocelligerous tubercle present in the male. 

Therioplectes. 

B. Eyes bare; no ocelligerous tubercle. . . Tabanus. 

C. Eyes pubescent; no ocelligeroiis tubercle. . Atylotus. 


XVII. FAMILY CYRTID^E. 


Fig. 66. 


Opsebius pterodontinus, enlarged. After Lugger. 


Small to large, never elongate, pilose or nearly bare 
flies. Head small or very small, formed chiefly by the 
large eyes, which are usually contiguous in both sexes 
above or below, or above and below the antennae; three, 
two or no ocelli present ; antennae composed of two or 
three joints, with or without a terminal arista or bristle. 
Proboscis rudimentary or long, sometimes very long. 
Thorax large, spherical; squamae very large and inflated; 
scutellum large. Abdomen closely united to the thorax, 
large and inflated. Legs rather stout; the tarsi with 
three membranous pads under the claws. Venation 
variable, the veins sometimes weak and indistinct; often 
a supernumerary cross-vein between the third and fourth 
veins. 

This family, the Cyrtidae or Acroceridae, comprises a 
small number of curious flies with curious habits. They 

182 


CYRTID^E. 


183 


are easily recognizable by their small head and large, in- 
flated squamae. No family characters can be drawn from 
the venation, owing to the great differences often exist- 


Fig. 67. Cyrtidse. i, Acrocera, wing; 2, Acrocera, head; 3, Phi- 
lopota, wing. 4, Philopota, head; 5, Oncodes, wing; 6, Oncodes, head; 
7 (number removed by engraver), Pterodontia, wing; 8, Pterodontia, 
head; 9, Ocncca, wing; 10, OcncEci, head; n, Eulonchus, wing; 12, 
Eulonchus, head; 13, Lasia, wing; 14, La si a > head. 


NORTH AMERICAN DIPTERA. 

ing between forms otherwise related. In the few forms 
in which the larvae are known they are parasitic upon 
spiders or their cocoons. 'In the spring of 1887, while 
hunting for spiders, I found hanging in cobwebs several 
soft white maggots and pupae. The webs were generally 
old and out of repair, and a closer examination showed 
that no living spider was in them, but almost every one 
had an empty skin of a common spider Amaurobius sylves- 
tris, nearly full grown. The skin of the legs and thorax 
was not clean like a moulted skin, but dirty and opaque, 
as though eaten out, and the skin of the abdomen when 
present was torn and shriveled. From this I concluded 
that the maggots came out of the spiders, and from their 
size must have nearly filled them. The maggots varied 
considerably in size, the largest being a quarter of an 
inch long, while others were not more than half as large. 
The hinder half of the body was thicker than the front 
half and nearly spherical. They hung head downward, 
holding to the web by their jaws and were also partly 
supported by threads under and around them.' The 
author of the foregoing, J. H. Emerton, reared from other 
specimens of these larvae a fly belonging to the genus 
Aciocera. The larvae of Astomella lindelii, according to 
Brauer, are so lodged in the abdomen of the spider that 
the posterior terminal stigmata are in relation with the 
lung-tubes of the spider. The eggs are said to be de- 
posited on dried twigs. 

TABLE OF GENERA. 

1. Antennae without terminal arista or style. .... 2 
Antennae with a terminal arista. ...... 3 

2. Antenme short, third joint rounded, with terminal bristly hairs. 3 
Antennae elongate. ........ 7 

3. Antennae inserted below the middle of the head in profile. . 4 
Antennue inserted above the middle of the head. 6 


CYRTIDJE). 

4. Wings with a stout costal spur near the tip of first vein (7,8) 

Pterodontia. 

Wings without such spur. ....... 5 

5. Proboscis small or vestigial* (5,6). . . . Oncodes. 
Proboscis elongate, directed backward; prothoracic lobes broadly 

united above (3, 4) . Philopota. 

6. Venation complete; eyes pilose (fig. 66) . . . Opsebius. 
Venation more or less obsolete; eyes bare (1, 2). . Acrocera. 

7. Proboscis very small, vestigial. ...... 8 

Proboscis elongate. ......... 10 

8. Eyes bare Appeleia. 

Eyes pilose or pubescent. .... ... 9 

9. Third joint of antennae with terminal bristly hairs. Pialeoidea. 
Third antennal joint not with terminal bristly hairs (9, 1O). 

Ocnaaa. 

10. Ocelli wanting; large flies (13, 14) . .... Lasia. 
Ocelli present; moderately large flies (11,12). . Eulonchus. 

* Compare Nothra americana Bigot. The occurrence of this genus 
in North America is doubtful. If, however, Bigot correctly recognized 
it, the species should be sought for under Oncodes. 


XVIII. FAMILY NEMISTRINID^. 

Species of moderate size, not elongate, thinly or densely 
pilose. Venation complicated; the fourth and fifth veins 
are curved forward to terminate before the tip of the wing; 
the anterior cross-vein is obsolete, that is the third and 
fourth veins coalesce for a short distance; basal cells 
long. Antennae small, short; third joint simple, w r ith a 
terminal, slender, jointed style. Proboscis sometimes 
elongate. Ovipositor of the female elongate, often slen- 
der. Tibiae without spurs ; empodia developed pulvilli- 
form, but, with the pulvilli often minute. (See fig. 69.) 


Fig. 68. Wing of Rhynchocephalus volalicus. 
a, third submarginal cell; b /" first fifth posterior cells. 

Throughout the world about one hundred species of 
this family are known, the larger part of which are from 
South America and Australia. Only six species are 
known from North America and two or three from all 
Europe. Some of the species have the wings with nu- 
merous cross-veins, almost recticulate in appearance. 
Megistorhynchus longirostris from Africa, though only 
about two-thirds of an inch in length, has a proboscis 
nearly three inches long. The adults are flower flies, 
resembling in their habits the Bombyliidae. 

But little is known of the larvae. The females of Hir- 
moneura obscura have been observed laying their eggs 
deeply within the burrows of Anthaxia, a wood-boring 


XEMISTRINIM. 


187 


insect, in the pine rails of fences. The eggs were found 
in clusters and the young larvae hatched from them differ- 
ed very singularly from those of a more mature growth. 
They were more slender, but differed chiefly in having each 
of the abdominal segments from the sixth to the twelfth 
provided with a pair of false legs bearing a single elon- 
gate seta at the tip, the hooks pointing backward; on the 
thirteenth segment there were two pairs of similar setae, 
the hooks of which, however, pointed forwards, thus en- 
abling the larva to attach itself firmly and raise itself 
erect. These young larvae issued in great numbers from 
the burrows in which they were hatched and, placing 
themselves erect, were blown away by the wind. Here 
for a time they have not been followed, but it is probable 
that they attach themselves by the aid of the ventral 
hooks to the bodies of large-sized beetles, by which they 
are carried into the ground when the females enter to de- 
posit their eggs. This is probable from the fact that 
hundreds of pupae and pupa skins were observed near 
the fence. On searching below these the larval skins 
were found at a depth of about two inches, and still deeper 
were found the remains of the beetles, Rhizotrogus solsti- 
tialfs, in some instances with the larvae yet within them. 
Females of Rhynchocephalus sackeni have been observed 
by Bruner apparently depositing eggs in the stems of 
Eriogon u m a la fit r,i . 

TABLE OF GENERA. 

i. Proboscis short, protruding but little from the oral opening; eyes 
bare or pilose; two or three submarginal cells. Hirmoneura. 

Proboscis long; antennae broadly separated; eyes bare; ovipositor 
composed of two slender lamellae; three submarginal cells 
present i^fig. 68). . . . . Rhynchocephalus. 


XIX. FAMILY APIOCKRID^. 

Rather large, elongate, chsetophorous, thinly pilose 
flies. Antennae three-jointed, with or without a small, 
short style. Front not excavated, broader in the female. 
Ocelli present. Face short. Proboscis not adapted for 
piercing, the labella not horny. Third longitudinal vein 
of wings usually furcate; basal cells large; five posterior 
cells present. Kmpodia wanting. Male forceps enlarged. 


Fig; 71. Apioceridae. Apiocera hanispe.r, head; 2, Apiocera Iiar- 
uspe.v, wing; 3, Apiocera, sp. (Australia) wing; 4, Apiocera (gen. nov. 
Australia) wing; 5, Rhaphiomidas acton, head; 6, Rhaphiomidas 
acton, wing. 


Less than a score of species of this family are known 

throughout the world, seven of which have been de- 

scribed from North America. The genera have been 

variously placed among the Mydaidse, Asilidae and 

1 88 


Fig. 69. Trichophthalma, species (Nemestrinidae); enlarged. 


Fig. 70. Apiocera, species; enlarged. (Australia.) 


APIOCERIDyE. 189 

Therevidae, but seem best isolated into a distinct group, 
though the relationships of Rhaphiomidas with the M.y- 
daidse are evident; perhaps as close as with Apiocera. 
The members of the genus Apiocera have much the ap- 
pearance of large Therevidae or of Asilidse, from which 
they will be at once distinguished by the anterior curva- 
ture of the third and fourth veins of the wings. The 
larvae are unknown. See fig. 70. 

TABLE OF GENERA. 

i. Palpi two-jointed, large; the second vein from the discal cell ter- 
minates beyond the tip of the wing (1, 2) . . Apiocera. 
Palpi one-jointed, small; the second vein from the discal cell ter- 
minates before the tip of the wing; proboscis elongate (Apomi- 
das] (5, 6) Rhaphiomidas. 


XX. FAMILY MYDAID^. 


Rather large to very large (see fig. i, page 16), thinly 
clothed or bare, elongated flies. Venation complicated, 
the basal cells long, the fourth vein always terminating 
at or before the tip of the wing ; posterior branch of 
fourth sometimes present and terminating also before the 
tip of the wing, as in Rhaphiomidas ( Apioceridae), but 
not present in American species. Antennae composed of 
four joints, the fourth always, the third usually elongate. 
Front excavated between the eyes; both sexes dichoptic; 
ocelli wanting. Proboscis with fleshy labella, and with- 
out palpi (in our species). Kmpodia very little devel- 
oped, not pulvilliform. 


Fig. 72. Mydaidae. i, Dolichogaster, wing; 2, Dolichogaster, 
antenna ; 3, Mydas, antenna. 

The family Mydaidae comprises only about a hundred 
known species, more abundantly represented in Austra- 
lia, Africa, South and Central America. The family 

190 


MYDAIDJB. 191 

comprises the largest of known diptera. The relation- 
ships of the family are very close with Rhaphiomidas of 
the Apioceridae, through the Tricloninae. 

The larvae of species of My das live in decaying wood, 
and it is probable that other members of the family have 
similar habits. They are known to be predaceous in 
some cases upon the larvae of beetles. The larvae of M. 
fulvipes are nearly two inches in length, with swellings 
below the abdominal segments for locomotion; the body 
is depressed and somewhat widened, with the posterior 
extremity broader and somewhat obtuse. The pupa of 
M. clavatus has at its anterior end two strong, sharp, out- 
wardly curved hooks ; the first abdominal segment has 
at its anterior border above, a row of very long, erect 
spines, curved backward at the tip. Another series of 
spines is situated on the anterior border of the last seg- 
ment; and, on the same segment there is a pair of hooks 
at the tip curved downward. 

TABLE OF GENERA. 

1. Terminal segment of the female abdomen with a circlet of spines. 3 
Terminal segment of female abdomen without circlet of spines.' 2 

2. Antennae but little longer than the head, the third short and the 

fourth expanded ; cross-vein between the second and fourth 
posterior cells present or not (1, 2) . . Dolichogaster. 

Antennae much longer than the head, the third and fourth joints 
elongated; the latter moderately or but slightly expanded (Phy- 
louiulas)*. (Fig. i, and 3.) . . . , . Mydas. 

3. Hind tibiae of female with spur; a short vein ends in hind margin 

of the wing between the second and fourth posterior cells. 

Ectyphus. 

Kind tibiae of female without terminal spur; no such cross-vein; 
proboscis elongate. ..... Leptomydas. 

* I have examined specimens of Phylomidas phylocerus, the type 
species of the genus, from Norton Count} 7 , Kansas, in the University 
of Kansas Museum. The genus is not valid, differing from Mydas 
only in the more expanded fourth antennal joint. 


XXI. FAMILY 


Fig- 75- Promachus vertebratus, natural size. After Washburn. 

Species cf moderate to large size, rarely small ; usu- 
ally more or less elongate in form, sometimes thickly 
hairy; always bristly, the bristles sometimes conspicu- 
ously strong; highly predaceous in habit. Head flatten- 
ed, broad and short, separated from the thorax by a 
freely movable neck. Front excavated between the eyes, 
dichoptic in both sexes, the front of the male not narrow- 
ed. Ocelli present, usually situated upon a rounded 
tubercle; front with bristles. Antennae porrect, simple, 
usually composed of three simple joints, the third more 
or less elongate, and with or without a terminal style or 
arista, the bristle exceptionally pectinate; sometimes 
the so-called style is thickened, forming one or two an- 
tennal joints. Proboscis never markedly elongate; firm 
and horny, adapted for piercing, directed downward, or 
downward and forward; labella never fleshy; palpi com- 
posed of one or two joints. Abdomen composed of eight 

192 


Fig. 73. Craspedia coriaria Life size. 


Fig. 74. Erax quadrimaculatus. Three times natural size. 


, i 9 3 

segments, the hypopygium and ovipositor usually promi- 
nent. Legs strong, bristly, of moderate length, rarely 
elongate and slender; tarsi strong; empodium bristle- 
like (31) or wanting, the pulvilli rarely vestigial. Squa- 
mae small. Wings when at rest lying parallel over the 
abdomen; basal cells long; two or three submarginal 
and five posterior (four in Townsendia and Leptopteromyia, 
35) cells present; first and fourth posterior and the anal 
cells closed or open. (Figs. 73 and 74.) 

The family Asilidae, or Robber-flies is one of the larg- 
est and best known among diptera, including about three 
thousand species, distributed in more than one hundred 
and fifty genera. Many of the species are conspicuous 
for their large size, the largest measuring nearly two 
inches in length, while the smallest known species is 
over four millimeters. The)- are, perhaps, the most pre- 
daceous of all flies in their habits. The greater part of 
them rest upon the ground in wait for their prey, arising 
with a quick buzzing sound when disturbed, to alight a 

/ 

short distance beyond. Some of 
the Laphrinae have a striking 
resemblance to humble bees, and 
are usually observed resting up- 
on foliage about the borders of 
forests. All their food, which 
consists wholly of other insects, 
is caught upon the wing; their 

luckless victims when once seiz- 
Fig. 76. Dasytus, species; , , , , . f 

natural size. After Kellogg. ed b > 7 their strong feet are pow- 
erless to escape. Their prey is 

usually other flies and hymenoptera, but flying beetles, 
especially the Cicindelae, are often caught, and they are 
known to capture and destroy large dragonflies. In one 
instance that the writer observed, a female seized a pair 
of her own species, and thrusting her proboscis into the 


194 


NORTH AMERICAN DIPTERA. 


195 


Fig. 76. Asilidse. i, Leptogaster, wing; 2, Leptogaster, antenna; 3, 
Leptogaster, end of tarsus (claw mostly cut away); 4, Damalis occi- 
dentalis, antenna; 5, Dicranus jaliscoensis, claw; 6, Stenopogon (Scle- 
ropogon] truquii, antenna; 7, Microstylum galactodes, wing; Psilo- 
curus, sp. antenna; 9, Laphystia, species, antenna; 10, Ceraturgus 
cruciatus, head; n, Myelaphns melas, head; 12, Dioctria nitida, anten- 
na; 13, Blepharepiumcoar datum, claw; 14, Deroniyiawinthemisn'wg', 
15, Deromyia, antenna; 16, Lestomyia fraudigera, head; 17, Taracti- 
cits, tibial spur; 18, Taracticus, antenna; 19. Cophura, antenna; 20, 
Nicocles rufus, wing; 21, Pseudorus, tibial spur; 22, Atomosia puella, 
wing; 23. Pogonosoma dorsata, wing; 24, Dasylechia (Hyper echia) 
atro.r, head; 25, Dasyllis, antenna; 26, Laphria, wing; 27, Omma- 
tiustibialis, antenna; 28, Eccritosia (Proctacanthns] amphinome, 
wing; 29, IMallophora, claw; 30, Promachus, wing; 31, Proinachus, 
claws; 32, Promachus, antenna. 

Fig. 77. Asilidse. 34, Pstlocurus caudatus, wing; 35, Leptoptero- 
myia gracilis (type, Brazil) ; 36, Holcocephala nitida, head, from in 


196 NORTH AMERICAN DIPTERA. 

thorax of the male, carried them both off together. The 
larvae live for the most part in rotting wood, under bark, 
or in soil containing decomposing vegetable matter, un- 
der leaves, etc., and feed upon grubs and other larvae. 
The larvae are cylindrical in shape, with parchment-like 
skin, the abdominal segments sometimes girdled with 
rounded tubercles, or with abdominal protuberances for 
locomotion, The pupae are free, with strong hooklets 
at the anterior end, the abdomen provided with spiny 
girdles, mixed with hairs below and behind; the last seg- 
ment has two short, divaricate hooklets and several 
smaller projections. 

The young larvae sometimes bore their way completely 
within the bodies of other larvae, remaining there till 
their food is wholly consumed. Often the larvae are 
found free in the earth, however, where their transforma- 
tions occur. The eggs are laid about grass stems, or in 
crevices of decaying logs and trees infested by the larvae 
of other insects. 

The division of the family into four subfamilies based 
upon the closure or non-closure of the marginal cell, and 
the presence or absence of a terminal bristly arista is ar- 
tificial in a large measure, but at the same time is very 
useful. I also doubt the importance of the terminal spur 
on the front tibiae as a true index of relationships. So 
far as my studies go, the structure of the palpi is a more 
natural character for subfamily division, the Dasypogo- 
ninae and L,aphrinae having two joints, the L,eptogas- 
trinae and Asilinae one. The L,eptogastrinae are, further- 
more, entitled to subfamily distinction because of the 


front; 37, Stenopogon (Sc/eropogon] truquii, head; 58, Archilestris 
magnificus, head; 39, Chrysoceria pictitarsis, head; 40, Dizonias,s\>. 
head; 41, Psendorus bicolor, head; 42, Atonia itiikii, head; 43, Ato- 
mosia macquartii, antenna; 44, Cerotainia, species, antenna; 45, 
Lampria, species, hind leg; 46, Laphria (Nnsa) , sp. , wing. 


remarkabh' attenuated body and the more generalized 
venation. The dividing line between the Dasypogoninae 
and Laphrinae will be more difficult to make, since there 
are forms with closed marginal cell whose natural rela- 
tionships are closer \vith the Dasypogoninae, and vice 
versa. It is probable that the following characters will 
be found the most natural, for the ordinary grouping at 
least: 

A. Palpi one-jointed; antennae with a slender terminal arista. 

B. Marginal cell open; very slender species. Leptogastrinae. 
BB. Marginal cell closed, less slender or robust species. 

Asilinse. 

AA. Palpi two-jointed; antennae with or without a thickened terminal 
style; very rarely with a terminal arista, 

C. Marginal cell open, or rarely closed at extreme tip. 

Dasypogoninae. 
CC. Marginal cell closed Laphrinse. 

TABLE OF GENERA. 

1. Marginal cell of wings open (14). . . . Dasypogoninae. 
Marginal cell closed (22, 23, etc.) 2 

2. Antennae with a terminal bristle (32). . . . AsilinaB. 
Antennae with or without a terminal style (24, 25). Laphrinse. 

DASYPOGONINGE. 
Marginal cell of irinys open; antenna icith or without a terminal stifle or bristle. 

1. Front tibiae with a terminal, claw-like spur (17). . . 32 
Front tibiae not with a terminal claw-like spur. ... 2 

2. Pulvilli vestigial or wanting, ...... 3 

Pulvilli normal (the hind pair rarely shortened). ... 5 

3. Third joint of antennae with an arista or aristiform style; abdomen 

very slender; hind femora much elongated and clubbed at ex- 
tremity (Leptogastrinae) (1, 2, 3). . . Leptogaster. 
Antennae not with a terminal arista. ..... 4 

4. Claws very long, with an elongated tooth at the base of each claw; 

large species (5). Dicranus. 

Claws normal; smaller species. .... Ablautus. 


198 


NORTH AMERICAN DIPTERA. 


5. Antennae with a slender, terminal arista (4). . Damalis. 
Antennae with or without a terminal style, the latter sometimes 

simulating antennal joints. ...... 6 

6. Only four posterior cells present; front very broad above; small 

species. Townsendia. 

Five posterior cells as usual. ....... 7 

7. Head narrow, about as high as broad; face narrow above, broader 

and swollen below, in large part covered with hair; large, elong- 
ate species. ......... 7 

Head very obviously broader than high. . 10 

8. Antennas with a terminal style. ...... 9 

Third joint of antennae long, without visible style; fourth poste- 
rior cell closed before the border of the wing; black species, 
with or without red on the abdomen. . . Ospriocerus. 

9. Style more than a fourth the length of the third antennal joint; a 

row of trichostical bristles usually present; first posterior cell 

usually closed (Scleropogon] (6, 37). . Stenopogon. 

Style about one-sixth the length of the third joint; trichostical 

bristles usually absent. ..... Stenopogon. 

10. Fourth posterior cell closed in or before the margin of the wing, n 
Fourth posterior cell wide open, rarely nearly closed. . 16 

11. Antennae much elongated, apparently composed of five joints. 17 
Antennae less elongated; style of antennae small or vestigial, not 

simulating antennal joints. ...... 13 

12. Face bare except on oral margin; large or very large species. 12 
Face hairy or bristly. ........ 14 

13. Vein posterior to the second posterior cell continuous or nearly so 

with the fourth vein beyond the discal cell, the last section of 
the fourth vein oblique, closing or much narrowing the first 

posterior cell (7). Microstylum. 

Last section of fourth vein continuous in nearly the same direction 
with the penultimate section, the first posterior cell not closed 
or narrowed (38). ..... Archilestris. 

14. Abdomen cylindrical*, not narrowed at tip, elongate ; near the 

proximal margin of the second and third segments with a white 

* Compare here Sphageus; I do not know the genus and can not 
locate it more precisely from the description. 


199 

pollinose, emarginate cross-band; wings dark; males very differ- 
ent in coloration from the females (4O). . . Dizonias. 
Abdomen less elongate, with five or six white-pollinose entire or 
interrupted cross-bands.* ....... 15 

15. Style of antennae vestigial ; veins at outer side of the discal and 

fourth posterior cells parallel or nearly so (8, 34). Psilocurus. 
Style distinct, though small; veins at outer side of discal and 
fourth posterior cells not at all parallel; marginal cell narrowly 
closed or open; first posterior cell open, closed or narrowed; 
face gently or not at all convex, more or less clothed with hair. 
(Triclis-\] (9) Laphystia. 

16. Antennae elongate, composed of five joints; nearly bare species of 

considerable size. ........ 17 

Antennae less elongate or rather short, the third joint with or 
without a short or slender style; no spine on upper side of third 
joint. ........... 19 

17. First joint of antennae about three times the length of the second, 

third elongate, fourth and fifth of nearly equal length; third 

and fourth at their tip with two lobes or processes reaching to 

about the middle of the following joint (11). Myelaphus. 

Third and fourth antennal joints not lobed at tip. . . 18 

iS. First and second joints of antennae of nearly equal length, the 
third elongate, fourth short, fifth elongate and densely pubes- 
cent (1O). Ceraturgus. 

First four joints of antennae as in preceding, the fifth oval, with 
a short lateral spine Ceraturgopsis. 

19. Style of antennae short, thick, obtuse, not easily distinguishable 

from the third joint, or, if so, forming apparent antennal joints; 
antennae more or less elongate. ..... 20 

Terminal style of the antennae more slender than the third joint, 
divergent or easily distinguishable; antennae usually shorter. 22 

20. Nearly bare species; face flattened, bare, save below. Small or 

rather small species, for the most part shining or metallic black, 
with narrow or cylindrical abdomen and large wings. . 21 

* If thorax and abdomen yellow and black, without pollinose cross- 
binds, the wings conspicuously orange-colored and blackish, Cacodcs- 
mon (Pro/epsis) S. A. 

t The so-called species of Triclis and Laphystia are very variable, 
and I doubt their generic distinction, notwithstanding the open or 
closed first posterior cell. 


200 NORTH AMERICAN DIPTERA. 

More pilose species, the bristles few and hair-like; antennae 
springing from a convexity, the facial profile thence receding 
to the tubercle, which is situated low down; abdomen short, 
head rather narrow. ...... Dicolonus. 

21. All the tibiae and the hind femora with short, strong setae. 

Echthodopa. 
Hind femora, at least, without such setae (12). . Dioctria. 

22. Abdomen slender; front broad anteriorly, very narrow behind, 

the ocelli far forward. ..... Plesioma. 

Front not narrowed behind. ....*.. 23 

23. Face distinctly swollen in profile, gibbous. 24 
Face flattened, or gently convex. ...... 25 

24. Rather or quite thickly pilose; the gibbosity of the face reaches to 

the base of the antennae; anal cell usually open. Cyrtopogon. 
Thinly pilose, more pollinose species; the convexity of the face is 
confined to the lower part; anal cell usually closed. 

Lasiopogon. 

25. Hind tibiae distally and the hind metatarsi much thickened. 26 
Hind tibiae not or but slightly thickened distally; hind metatarsi 

not enlarged. ......... 27 

26. Head much broader than high, transverse, goggle-like in appear- 

ance; abdomen short; wings large (compare Metapogori] (36). 

Holcocephala. 

Head only moderately broader than high, not at all spectacle-like 
in appearance Holopogon. 

27. Abdomen with thick, recumbent pile above; thickly pilose spe- 

cies; antennae slender. ..... Pycnopogon. 

Abdomen not with such pile above. ..... 28 

28. Slender, nearly bare species; face perpendicular, straight or gently 

concave in profile, narrowed above, and bare, except on oral 

margin. 29 

Face gently rounded, not prominent below, in large part hairy, 
and but slightly or not narrowed above. ... 30 

29. Thickly whitish pollinose ; abdomen flattened, usually reflected 

upward; third joint of antennae and the style both slender. 

Stichopogon. 

Less thickly pollinose; abdomen cylindrical, a little broader at the 
base; third joint of antennae short and broad, the style minute. 

"Habropogon". 


201 

30. Large, elongate species, the style of antennae short. Callinicus. 
Moderately large, not markedly elongate species. . , 31 

31. Abdomen broader at base, depressed; thorax often strongly con- 

vex above, antennae slender, the style long and slender (com- 
pare also species of Cyrtopogon and Metapogon] . 

Heteropogon. 
Abdomen short, cylindrical; black, with bright golden, opaque 

pollinose markings on thorax and abdomen (39) . 

Chrysoceria. 

32. Face bare, with bristles on oral margin, in profile straight or gen- 

tly concave, the oral margin most prominent. . . . 33 

Face convex below, the oral margin not the most prominent, more 

or less covered with hair. ....... 35 

33. Fourth posterior cell closed a considerable distance before the 

margin of the wing; antennae without style. ... 34 
Fourth posterior cell open or closed in the margin. Saropogon. 

34. Posterior pulvilli much shorter than the elongated claws; abdomen 

contracted toward the base (13)*. . . Blepharepium. 

Posterior pulvilli not much shorter than the claws; abdomen not 

contracted toward the baset (14,15). . . Deromyia. 

35. Third joint of the antennae more or less dilated, the style very 

short (16). Lestomyia. 

Third joint of antennae slender, elongate. .... 36 

36. Head broad and flat, the face not gibbous. .... 37 

Face convex, densely covered with hair; thickly hairy species. 

Lastaurus. 

37. Third joint of the antennae with an excision on the upper border 

before the tip, bearing a small spine; abdomen punctulate (17, 

18) (Dioctrodes Coq.) Taracticus.J 

Third antennal joint with a small terminal style; abdomen smooth, 
not punctulate. ......... 38 

38. Abdomen flattened, in the male a little broader beyond the mid- 

dle; in the male near the tip, the last two segments conspicu- 
ously silvery above (2O). ..... Nicocles. 

Abdomen of male not flattened and silvery distally (19) . 

Cophura. 

* If abdomen not contracted toward the base, the scutellum w 7 ith 
bristles, Allopogon, S. Amer. 

t If abdomen contracted toward the base, the scutellum without 
bristles Senobasis (Lochites], S. Amer. 

+ T. vitnpennis and T. mger, with a large two-jointed style, and 
without lateral spine, must be separated generically. 

20 


202 NORTH AMERICAN DIPTERA. 


Man/inn/ cell closed, antennae ir/f/i or tritli/mt <i terminal style, nut. with 

terminal hrist/r. 

1. Front tibiae with a terminal, claw-like spur. . 2 
Front tibiae not with such spur. . . 3 

2. Thorax projecting prominently in front (21, 41). Pseudorus. 
Thorax not projecting prominently in front.* . Doryclus. 

3. Veins at distal ends of the discal and fourth posterior cells paral- 

lel or continuous in the same straight line. . 4 

Veins at distal ends of discal and fourth posterior cells very dis- 

tinctly angulated and not parallel. . . 7 

4. Third joint of antennae with a terminal style, in length greater 

than the first two together; eyes not or but slightly emarginated 

on the sides of the front, the front much wider above; scutellum 

without bristles, or with hairs; small species (42) . Atonia. 

Third antennal joint without terminal style. . 5 

5. Third joint of antennae at least three times as long as the first two 

together; rather large species. . , Aphestia. 

Third antennal joint not more than twice the length of the first 

two combined; small species. ... 6 

6. First antennal joint more than twice the length of the second; front 

much widened above, the eyes disciform and with enlarged fa- 
cets in front; scutellum with weak bristles ; body punctulate 
(44). ........ Cerotainia. 

Third joint of antennae not more than twice the length of the sec- 
ond; eyes on the sides of the front emarginate, the front not 
widened above; scutellum with bristles; first posterior cell usu- 
ally narrowed; body punctulate (22, 43). . Atomosia. 

7. Three submarginal cells present; first posterior cell closed or nar- 

rowed (23). ...... Pogonosoma. 

Two submarginal cells. ..... 8 

8. Antennae with a distinct terminal style. . 9 
Antennae not with a terminal style. ... 10 

9. Rather small, nearly bare species, with pollinose spots or fasciae 

on the abdomen; first posterior cell open or closed (see Dasypo- 
goninae, 16; Laphysha.} 

* The distinction between these two genera seems doubtful to me. 
Megapoda is a distinct genus, characterized by the hind tibiae and 
metatarsi not being thickened; the name is not preoccupied. 


ASILIM). 


203 


Very large, robust, thickly hairy species; first posterior cell nar- 
row throughout; hind femora of nearly equal thickness through- 
out \Hyperechia\ 24 ...... Dasylechia. 

10. Densely pilose , large species, the abdomen short and broad, usu- 

ally broader beyond the middle (25) . . . . Dasyllis. 

More elongate, less hairy or nearly bare species, the abdomen not 

distinctly broader beyond the middle. . . . .11 

11. Body nearly bare: hind femora usually with spinous tubercles be- 

low; species of rather moderate size (45) . . . Lampria. 

Body more or less hairy, from rather small to large size; first pos- 

terior cell often narrowed or closed (Xusa}\ hind femora not 

with spinous tubercles below (26, 46). . . Laphria. 


Marginal re/l closed; antenna (ilirdi/s ir/f/i <i /<>ni/ terminal '.inxtu. (32. ) 

1. Bristle of antennae pectinate below ( 27) . . . Omniatius. 
Bristle of antennae bare. ........ 2 

2. The veins closing the discal and fourth posterior cell in the same 

straight line or parallel. .... Atractia. 

The veins closing the discal and fourth posterior cells not parallel. 3 

3. The posterior branch of the third vein curves forward to meet the 

costa at or before the tip of the wing; or the anterior branch of 

the third vein angulated near its origin, with stump, or both. 4 

The posterior branch of third vein terminates beyond the tip of the 

wing; the anterior branch without stump. .... 6 

4. Ovipositor cylindrical, with a terminal circlet of spines. . 5 
Ovipositor laterally compressed, without terminal circlet of spines 

(fig. 74) .......... Erax. 

5. Abdomen shorter than the wings (28) . . . . Eccritosia. 
Abdomen longer than the wings (28). . . Proctacanthus. 

6. Two submarginal cells. ....... Asilus.* 

Three submarginal cells. ..... 7 

7. Abdomen shorter than the wings; body thickly pilose; claws obtuse 

(29) .......... Mallophora, 

Abdomen longer than the wings; body thinly pilose; claws more 
pointed (SO, 31, 32). ... . Promachus. 

* In general the subdivisions of the old genus ^-] si/us are very vague 


204 


NORTH AMERICAN DIPTKRA. 


SUBGRNKRA OF ASII..US. 

a. Ovipositor laterally compressed. ..... b 

Ovipositor conical. ........ h 

b. Tbinl antennal joint unusually hairy*. . Anarmostus. 
Third antennal joint not unusually hairy. c 

c. Face without gibbosity, narrow throughout, not at all carinate, 

the mystax composed of a few long hairs. Seiioprosopis. 
Face with gibbosity, or not unusually narrow. . . d 

d. Posterior border of the last ventral segment in the male more or 

less widened. . Machimus. 

Posterior border of the last ventral segment of the male not un- 
usually widened. ........ e 

e. Legs prevailing shining yellow in color. Heligrnoneura. 
Legs prevailingly black, or light and opaque colored. . f 

f. Abdomen shining black above and below. Stilpnogaster. 
Abdomen not shining black above and below. g 

g. Male genitalia club-like. ..... Neoitamus. 

Male genitalia not club-like; the sixth and seventh segments 

take no part in the formation of the female ovipositor. 

Tolmerus. 
h. Abdominal segments with bristles before the incisiires. 

Philonicus.t 
Abdominal segments not with bristles before the incisures, i 

i. Bright-colored, larger species. ..... Asilus. 

Small, ashy gray species Rhadiurgus. 

and hard to define, and many of them are doubtfully entitled to recog- 
nition. At the most, few if any of them are based upon real generic 
characters, and the names are only useful as aids in the determination 
of the numerous forms. 

The groups Epitriptus, Lophonotus and Neoeristicus have also 
been reported from Central America by Bellardi and Bigot, but there 
is doubt as to their correct reference. 

* The only reported species of Anarmostus is from Brazil and Brit- 
ish Honduras. It has the abdomen deep steel blue and black, the 
wings deep steel blue (16 mm.) 

t Loew. Linn. Ent. 144; Philodicus Loew, Dipt. f. S. Afr. p. 144. 


XXII. FAMILY THEREVID^E. 


Fig. 79. Therera setie.v, enlarged. After Lugger. 

Rather small or moderate sized, elongate (American 
forms), bristly, sometimes pilose, predaceous flies. Eyes 
of the male contiguous or approximated; front in the 
female not excavated. Antennae composed of three 
joints, the third simple, with a terminal style, sometimes 
wanting. Proboscis projecting, the labella broad; palpi 
two-jointed. Ocelli present. Abdomen elongate, geni- 
talia moderately or but little prominent. Legs with bris- 
tles; empodia wanting; pulvilli rarely wanting. Third 
longitudinal vein of the wings furcate, the posterior 
branch terminating beyond the tip of the wing; five pos- 
terior cells, anal cell usually closed toward the margin 

of the wing. 

205 


20 6 NORTH AMERICAN DIPTERA. 

The family comprises about two hundred known spe- 
cies, with but few widely distributed genera. The flies 
resemble the Asilidae somewhat, and have habits not 
dissimilar, though much less active. The proboscis has 
fleshy labella, instead of the horny tip of the Asilidae, 
and the legs are less stout in many species they are 
easily broken off when captured. Their food is chiefly 
other diptera, for which they lie in wait upon leaves and 
bushes, or upon the bare ground. The larvae have a 
short, eyeless, nonretractile head, the antennae small and 
short. The body is slender and snake-like, showing ap- 
parently nineteen segments. Anterior spiracles situated 
at the end of the first segment behind the head; poste- 
rior spiracles on the apparently seventeenth segment. 
The larvae live in the earth and decomposing wood, or 
in sand, feeding upon other insects or upon vegetable 
matter, ordure, etc. The pupae are free; they have in 
front laterally projecting spinous points. 

The genera of this family are, for the most part, very 
unsatisfactorily founded. Few structural differences ex- 
ist, save in the antennae and proboscis, and these differ- 
ences seem usually to have specific value only. Five 
genera have been proposed for North American species; 
each contains a single species, and in all probability 
there never will be any additions to them. On the other 
hand Thereva and Psilocephala, with numerous species, are 
doubtfully distinguished by the vestiture of the face ! 
If the smaller genera are recognized, at least one or 
two more should be formed for those species of Thereva 
having a thickened first antennal joint ( T. melanopheba 
Loew, T. crassicornis Bell., T. pachyceras, n.n. for T. 
crassicornis Will.) The closure or non-closure of the 
fourth posterior cell occurs in both genera and compli- 
cates matters. The division of the first posterior cell in 


THEREVID.E. 


207 


Metaphragma is, I believe, purel} T a specific character, 
and will not be found in allied species. 


Fig. 80. Therevidse. I, Tabuda, head; 2, Psiloccphala, wing: 3, 
Psilocephala.) antenna. 

TABLE OF GENERA. 

1. First antennal joint much thickened and elongate. . . 2 
First antennal joint not noticeably thickened. ... 5 

2. Head not as broad as long; vertical diameter of the eyes equaling 

the horizontal diameter; eyes of male dichoptic. Nebritus. 
Head distinctly broader than long. ...... 3 

3. Third antennal joint about one-third the length of the first; fourth 

posterior cell open. ........ 4 

Third antennal joint more or less elongated. . Thereva, pt. 

4. First posterior cell divided by a cross-vein. . Metaphragma. 
First posterior cell not divided by a cross-vein ( ? Pachyrhiza, 

? Baryphora] (1). . .... Tabuda. 

5. Third joint of the antennae about four times the length of the first; 

without style; fourth posterior cell closed; front of male broadly 

dichoptic Henicomyia. 

Third joint of antennae not four times the length of the first; fourth 
posterior cell open or closed. ...... 6 

6. Face bare; usually more bare and shining species (2, 3) (Ozodi- 

ceromyia] . ....... Psilocephala. 

Face distinctly pubescent or hairy; usually more pilose and polli- 
nose species. (Fig. 80; also fig. 15, p. 42, not Rhyphus.} 

Thereva. 


XXIII. FAMILY SCHNOPINID^B. 


Flies of moderate or small size; generally black in 
color and bare. Front not excavated; face bare, short 
and broad. Antennae approximated at the base, the first 
two joints short, the third elongated, simple, without 
style or arista. Proboscis concealed; palpi cylindrical, 
bristly at the tip. Ocelli present. Males usually holoptic. 
Thorax rather long, moderately convex, though appar- 
ently much so from the low position of the head. Scutel- 
lum broad and short, without spines or tubercles. Ab- 
domen flattened, or cylindrical, composed of seven 
segments. Squamae small. Empodia wanting. Third 
longitudinal vein of the wing furcate; basal cells long, 
the first much longer than the second; three posterior 
cells, the first narrowed in, or closed before the margin ; 
anal cell closed. 


Fig. Si. Scenopinidae. i, Seen op hi us , wing; 2, Scenopinus, head; 
3, Metatrichia, wing; 4, Metatrichia, head; 5, Pseuda.tr ichia, wing. 

The larvae resemble closely those of the Therevidae. 
They are very long and slender, having apparently nine- 

208 


SCENOPINID.E. 


209 


teen segments, due to each of the abdominal segments 
except the last being partially divided by a strong con- 
striction. The larvae have been found in decaying fungi 
and wood and under carpets or in furniture, and are sup- 
posed to be carnivorous. The flies are not very active 
in their habits, and because of the frequency with which 
some are observed on window-panes are usually called 
window-flies. 

TABLE OF GENERA. 

1. First posterior cell open (1, 2) Scenopinus. 

First posterior cell closed before the margin of the wing. . 2 

2. Body short, clothed with scales (3, 4). . . Metatrichia. 
Body elongate, without scales (5) .... Pseudatrichia. 


XXIV. FAMILY 


Fig. 84. Bombylius major, enlarged. After \Vashburn. 

Rather large to small flies; often with abundant, long 
and delicate hair, rarely with conspicuous bristles. Head 
as broad as, or narrower than the thorax, often spheri- 
cal in shape, closely applied to the thorax. Eyes large, 
often contiguous above in the male, and rarely also in 
the female. Antennae porrect, usually of moderate length 
or quite small; third joint simple; style usually small 
and indistinct, never more than two-jointed, and some- 
times wholly indistinguishable. Ocelli present. Probos- 
cis sometimes short, with broad labella; usually project- 
ing from the oral cavity, sometimes long and slender. 
Abdomen composed of from six to eight visible segments, 
slender in a few genera only. Legs moderately long and 
weak, with short, weak bristles or spines. Pulvilli 


2IO 


Fig. 82 


Fig. 83 


Fig. 82. Oncodocera, sp. (Brazil). 
Fig. 83. Systropus, s^. (Brazil). 


BOMBYLIIM). 


211 


Fig. 85. Exoprosopa y sp., en- 
larged one half. After Kellogg. 


sometimes rudimentary, the empodia almost always so; 
tarsi and claws usually small. Squamae small. Wings 
often with dark markings; two or more submarginal,* 
three or four, rarely fivet posterior cells present; discal 
cell present in all our genera (absent in Apolysa, Cyrtosia}; 
anal cell closed in or near the margin, or narrowly open. 

The family Bombyliidse 
comprises about fifteen hun- 
dred known species. Most 
of them are swift-flying in- 
sects, often hovering motion- 
less in the air for a time and 
darting away like a flash. 
They seek sunny places in 
woodland roads, about blos- 
soms or on rank vegetation. 
The Anthracinse are a group especially characteristic of 
arid regions. In general the members of the family are 
prettily and delicately marked, and their life histories 
are often very interesting. In the adult state they are 

* The aberrant genus Mythicomyia described as an empidid, may 
possibly belong in this family. Without expressing an opinion as to 
its real relationships, it will be. easily recognized by its very short 
second longitudinal vein, and its single submarginal cell. See figs. 
25 and 26, and fig. 12 of the Bmpididae. 

t The presence of but four posterior cells in most members of this 
family, as doubtless in other forms having a like number, is due to 
the loss of the vein between the third and fourth cells, and not to the 
coalescence of veins. Certain .species of Anthrax, and perhaps of 
other genera, have this vein persistent or vestigial. In those species 
having but three posterior cells the reduced number is likewise due to 
the loss of the vein between the second and third cells, so that the 
second posterior cell in such forms is really the coalesced second, third 
and fourth posterior cells (see figs. 1 and 21). This does not accord 
with the Comstock-Needham system of nomenclature, but I believe is 
certainly demonstrable. 


212 


NORTH AMERICAN DIPTRRA. 


BOMBYLIID^E. 213 

flower flies, feeding upon the pollen and honey within 
the blossoms, extracted by aid of their often long probos- 
cis. The larvae of species of Aphcebantus and Systcechus, 
occurring in western America, are found in the egg-pods 
of the locust, Caloptenus spietus. 'The larvae begin to 
transform themselves into the pupa state early in the 
summer, and the pupa pushes itself half way out of the 
ground in order to disclose the fly. They continue to 
issue during the summer months. Aphcebantus is first 
observed as a yellowish white grub, about half an inch 
long when extended, it being usually curved so that the 
head and tail nearly meet. It is usually found in a case 
of locust eggs which it has devoured, pushing the empty 
shells aside, and at last occupying the space where were 
twenty-one to thirty-six eggs. Often it is found in a lit- 
tle space below a number of egg-cases, as though it had 
feasted off the contents of several nests' (Riley). The 
larvae of Anthrax have been found parasitic upon Mega- 
chile, Osmia, Odynerus, Mamestra, Noctua and Agrotis ; 
those of Spogostylum upon Pelop<zus, Megachile, Cemonus, 
Osmia, Cicindela and Calicodoma; those of Bombylius upon 
Andrena and Collettes; those of Toxophora upon Eumenes; 
those of Callostoma in the egg-cases of Caloptenus italics; 
those of Systropus upon Limacodes. 


Fig. 86. Bombyliidae. i, Anthrax, wing; 2, Hyperalonia, wing; 
3, Exoprosopd) wing; 4, Exoprosopa, hind claw; 5, Spogostylum, 
antenna; 6, Anthrax, antenna; 7, 8, Exoprosopa, antennae; 9, Bom- 
bylius, wing; 10, Pantarbes, wing; n, Pantarbes, antenna, 12, Sys- 
toechus, wing; 13, Lordotus, wing; 14, Lordotus, antenna; 15, Phthi- 
ria, wing; 16, Phthiria, antenna; 17, Sparnopolius, antenna; 18, 
Geron, w T ing; 19, 20, Geron, antennae; 21, Toxophora, wing; 22, Tox- 
ophora, antenna; 23, Systropns, wing; 24, Systropus, antenna; 25, 
Mythicomyia, wing; 26, Mythicomyia, antenna. 

21 


214 


NORTH AMERICAN DIPTERA. 


TABLE OF GENERA. 

1. The bifurcation of the second and third veins takes place opposite 

or nearly opposite the anterior cross-vein, the distance not ex- 
ceeding the length of the cross-vein; the second vein forms a 
knee at its origin, the third vein in a straight line with the pre- 
furca. ........... 2 

The bifurcation of the second and third veins takes place at a 
greater distance from the cross-vein, usually at an acute angle. 12 

2. Antennal style distinct, that is it is separated from the third joint 

or the styliform prolongation of the joint by a distinct suture. 3 

The third joint not with a distinct, suturally separated style, the 

style when present very minute. ..... 7 

3. Antennal style with a pencil of hairs at the tip; pulvilli distinct; 

front tibiae with bristles. . . .... 4 

Antennal style not terminating in a pencil of hairs; three or four 
submarginal cells present. ....... 5 

4. Outer submarginal cell bisected by a cross-vein (Coquillettia, 

preoc.) Spogostylum. 

Outer submarginal cell not bisected by a cross-vein; the anterior 
branch of the third vein sometimes connected with the second 
by a cross-vein forming three submarginal cells (Argyramosba) 
(5) Spogostylum. 

5. Pulvilli distinct (1O, lOa, p. 80) Aldrichia. 

Pulvilli vestigial or wanting. ..*.... 6 

6. Outer submarginal cell divided by a cross-vein, making four sub- 

marginal cells (2) Hyperalonia. 

Outer submarginal cell not divided by a cross-vein; posterior claws 
with a basal tooth (fig. 85, 3, 4, 8) . . . Exoprosopa. 

7. Eyes of male contiguous at the vertex; anal cell closed. 

Astrophanes. 
Eyes of male not contiguous at vertex; anal cell open. . . 8 

8. Anal cell widest at the middle. ...... 9 

Anal cell widest at the margin. ..... Mancia. 

9. The second vein strongly contorted at the distal end in the shape 

of a recumbent letter S; three submarginal cells present. 

Dipalta. 
The second vein not so contorted at end. . . . . 10 

10. Three submarginal cells normally present; proboscis elongate 

(Stony.r] Anthrax. 

Two submarginal cells normally present. . . . .11 


215 

IT. The contact of the discal cell with the third posterior not much 
longer than its contact with the fourth posterior; proboscis long; 
sides of the abdomen with a fringe of scales and not with hairs 

only. . Lepidanthrax. 

The contact of the discal cell with the third posterior at least twice 
as long as its contact with the fourth posterior; the latter con- 
tact often merely punctiform (1, 6) . . . . Anthrax. 

12. Wings with three posterior cells. ...... 39 

Wings with four posterior cells. ...... 13 

13. First posterior cell closed, or at most very narrowly open (Para- 

bombylius] . ......... 14 

First posterior cell open. ....... 21 

14. Three submarginal cells. . . . . . . . 15 

Two submarginal cells. . . . . . . . . 16 

15. Head broader than thorax; posterior orbits not excised (1O, 11). 

Pantarbes. 
Head narrower than thorax, posterior orbits excised. 

Triplasius. 

16. First basal cell longer than the second. .... 17 
First basal cell not longer than the second; the anterior cross-vein 

situated near the base of discal cell. ..... 20 

17. Proboscis very short, not protruding beyond oral margin; anal 

cell usually closed; frontal triangle of male large, the eyes nar- 
rowly contiguous; large species (Anisotamia) . Oncodocera. 
Proboscis more or less elongate; anal cell usually open. . 18 

18. First posterior cell closed at some distance from the border of the 

wing. ........... 19 

First posterior cell narrowed, or closed in or near the border of the 
wing; front with a silvery spot on each side below; rather small 
species (5-8 mm) Parabombylius.* 

19. Head comparatively small; the emargination of the occipital orbits 

almost imperceptible (fig. 84, 9). . . . Bombylius. 
Head broad; emargination of the occipital orbits distinct. 

Heterostylum. 

20. Face thickly clothed with pile. . . . Anastcechus. 
Face sparsely clothed with pile (12) . . . Systoschus. 

* Bombylius ater, syndesmus, albopemcillatus, dolorosns. 


2I 6 NORTH AMERICAN DIPTERA. 

21. Two submarginal cells present 26 

Three submarginal cells. .22 

22. Bare species; tibiae without bristles; abdomen narrow. 

Amphicosmus. 
More or less pilose species; tibiae with bristles. . . 23 

23. Antennae as long as the head, the third joint not longer than the 

first two together 24 

Antennae shorter than the head; the third joint twice as long as 
the first two together. Exepacmus. 

24. First antennal joint not thickened. ..... 25 

First antennal joint extraordinarily thickened. . . Ploas. 

25. ' Scutellum deeply sulcate longitudinally'. . . Gemmaria. 
Scutellum convex; not sulcate (13, 14). . . Lordotus. 

26. Anal cell open. 29 

Anal cell closed. . 27 

27. Proboscis short; frontal triangle of male large (fig. 82) . 

Oncodocera. 
Proboscis elongate. . . , 28 

28. Third joint of the antennae with long bristly hairs; face with long 

hair Acreotrichus. 

Third joint of antennae withoiit, or with short bristly hairs above; 
face bare or short pilose (15, 16) .... Phthiria. 

29. Body clothed with more scales than hairs, gibbous; antennae long, 

the first joint unusually long (2O, 21, p. 80). Lepidophora. 
Body clothed chiefly with hair, or nearly bare. ... 30 

30. Alulae wholly wanting; thorax and posterior margins of the ab- 

dominal segments with bristles; all the tibiae with bristles; first 

and third antennal joints subequal. . Sphenoidoptera- 

Flies not having the above assemblage of characters. . . 31 

31. Body more or less pilose; tibiae usually bristly. ... 32 
Body bare; tibiae bare or feebly bristly. .... 37 

32. Both basal cells of nearly equal length (17). Sparnopolius. 
First basal cell distinctly longer than the second. . . 33 

33. Third antennal joint but little longer than the first; mesonotum 

of male sometimes muricate and the costa denticulate (19, p. 80) . 

Eclimus. 


2I y 

Third joint of antennae more than twice the length of the first, 
bulbous at the base. ........ 34 

34. The origin of the second section of the second vein is before the 

proximal end of the discal cell in an acute angle.. . . 35 
The origin of the second section of the second vein is beyond the 
proximal end of the discal cell and is rectangular. 

Desmatoneura. 

35. Third antennal joint scarcely longer than wide. . Eucessia. 
Third antennal joint much longer than wide. ... 36 

36. Face projecting in profile. ..... Epacmus. 

Face retreating in profile. .... Aphcebantus. 

37. Ocellar tubercle situated near vertex. ..... 38 

Ocellar tubercle situated near middle of front. Metacosmus. 

38. Antennae elongate, third joint flattened, the style broad and dis- 

tinctly composed of two segments (B, 9, p. 80, type) . 

Desmatomyia. 
Antennae not elongated nor with such a style. Paracosmus. 

39. Slender, elongate species, with slender legs. ... 40 
Shorter, more thick-set species, the abdomen never cylindrical. 41 

40. Both males and female holoptic; abdomen enlarged at extremity 

(fig. 82, 23, 24) Systropus. 

Males holoptic, the females dichoptic; abdomen cylindrical, not 
enlarged at extremity (11, p. 80) . . . Dolichomyia. 

41. Three submarginal cells. ....... 42 

Two siibmarginal cells (18, 19, 2O) Geron. 

42. Body clothed with more scales than hairs, usually with thoracic 

bristles; abdomen decumbent; antennae long (21, 22) . 

Toxophora. 
Body clothed chiefly with hair; abdomen not decumbent. 

Rhabdopselaphus . 


XXV. FAMILY 

BY PROF. A. L. MKI^ANDER. 

Flies ranging in size from three-fourths of a millimeter 
to fifteen millimeters, though rarely more than ten milli- 
meters in length. Head more or less spherical, loosely 
connected with the thorax. Males holoptic or dichoptic, 
the front never excavated. Ocelli present. Antennae 
porrect, approximated at their base, composed of two or 
three simple joints; third joint variable in shape, with or 
without a terminal style or arista, the latter rarely dor- 
sal in position. Face without mystax, or fringe-like 
row of bristles on the oral margin. Proboscis short or 
long, usually rigid, projecting downward, forward or 
backward. Thorax sometimes very convex. Male geni- 
talia usually prominent and of complicated structure; 
ovipositor simple. Squamae small. Legs usually slender, 
often with structural peculiarities, such as the coxae or 
femora lengthened, femora or tibiae thickened and spin- 
ose, or with projections or fringes of scales, the metatarsi 
flattened, etc. Pulvilli usually distinct ; enipodia usually 
membranous and linear. Venation variable; discal cell 
occasionally absent; the third longitudinal vein furcate 
or not; three or four posterior cells present, anal cell 
longer or shorter than the second basal cell, closed be- 
fore the margin of the wing, sometimes wholly wanting.* 

The family Empididae is a large and complex one, in- 

* Hilarimorphan&& Mythicomyia(fig. 12, and figs. 25, 26 Bomby- 
liidae) have been included in the Empididae. Both of these genera have 
the anal cell narrowly open or closed in the border and are wholly 
bristleless. The former germs will be found under the L,eptidae; the 
latter is figured with the Bombyliidae. 

218 


EMPIDIDJB. 


219 


Fig. 87. Empididae. i, Hybos; 2, Toreus; 3, Hesperempis; 4, Oreo- 
geton; 5, Prorates; 6, Heleodromia; 7, Ocydromia; 8, Coloboneura; 9, 
Toreus, antenna; 10, Prorates, antenna; u, Hesperempis, antenna; 
12, Mythicomyia. Drawings by A. L,. Melander. 


220 NORTH AMKRICAN DIPTERA. 

eluding many genera and species. Most of the species 
can be recognized by their spherical head, large eyes, 
piercing proboscis, large thorax and slender legs and 
abdomen. Some of the minute forms resemble certain of 
the Platypezidae or smaller muscids. The members of 
the family are for the most part modest in coloration, 
gray, blackish or reddish; a few tropical forms are me- 
tallic. They are all predaceous, preying upon smaller 
flies, which they impale on their proboscis. Microphones 
and Anthalia and their allies, are common visitors to 
flowers. Some species of Rhamphomyia, Empis and Hilara 
dance in the air in immense swarms. The species of Clino- 
cera are sluggish, and may be found along the banks of 
streams. Tachydromia runs sw r iftly over stones in search of 
prey. Some species of Hilara and Empis construct peculiar 
frothy balloons at mating time. The peculiar armature 
of the legs is mostly a sexual characteristic possessed by 
the males. Empididae are especially abundant in moun- 
tainous, damp and woody regions during the early sum- 
mer; they are pre-eminently a boreal group. In dry 
regions they are rare, perhaps a result of the dominance 
of the related but more powerful Asilidse. 

The larvae of this family are nearly cylindrical, taper- 
ing anteriorly, with a very small and partly retracted 
head. The abdominal segments have more or less promi- 
nent prolegs. The larvae live in decaying vegetable mat- 
ter or in running streams; the pupae are free. The early 
stages of Empididae are but little known. 

TABLE OF GENERA. 

i. Anal cell wanting or incomplete; cliscal cell always united with 
the second basal; three posterior cells; third longitudinal vein 
simple; antennas two or three-jointed: femora often thickened 
and mucronate below. .... Tachydromiinse. 
Anal cell complete; or, if incomplete, the front coxae are greatly 
lengthened; often four posterior cells; third longitudinal vein 
often furcate. 2 


221 


Fig. 88. Empididae. 13, Oreothalia, wing; 14, Blepharoprocta, wing; 
15, Microdromia, wing; 16, Tachypeza, wing; 17, Lamprempis, wing; 
18, Tachypeza, front leg; 19, Drapetis, wing; 20, Drapetis, antenna; 
21, Hybos, wing; 22, Empis< wing; 23, Geron (Bombyliidae) , wing; 24, 
Empimorpha, head; 25, Syneches, wing; 26, Neoplasta, wing; 27, 
Hilara, wing. 

2. Anal angle of wing not projecting, the outline of wing nearly cunei- 
form ; front coxae more or less lengthened ; proboscis short, 
fleshy, or sharp and incurved. . . Hemerodromimse. 
Anal angle of wing more or less projecting, often rectangular; 
wings not uniformly tapering to the base; front coxae not elon- 
gate; proboscis usually rigid. ...... 3 


222 NORTH AMERICAN DIPTERA. 

3. Anal cross-vein forming a distinct angle with the basal part of the 

anal vein ; proboscis rarely longer than head ; thorax often 
large. ... ....... 4 

Anal cross-vein recurved and confluent with the anal vein, or form- 
ing part of the posterior side of the anal cell; proboscis often 
elongate, rarely projecting forward ; antennas usually three- 
jointed Empidinse. 

4. Anal cell as long as the second basal, or longer, its outer angle 

acute. ........... 5 

Anal cell shorter than the second basal, its posterior angle obtuse 
or the anal cross-vein perpendicular to the anal vein; proboscis 
short, rarely porrect; thorax seldom excessively convex. 

Ocydromiinse 

5. The discal cell emits three veins; proboscis short, sharp and incurv- 

ed; thorax comparatively small; antennae three-jointed. 

Brachystomatinse. 

The discal cell emits two veins; proboscis rigid, projecting forward; 
thorax greatly arched; antennae two-jointed. Hybotinse. 

TACHYDROMIIN^. 

1. Both the sixth vein and the anal cross-vein present, though some- 

times feeble. ....... .2 

Both the sixth vein and the anal cross-vein completely wanting. 3 
The sixth vein wanting, the anal cross-vein present; marginal cell 

long along the costa; first basal cell shorter than the second; 

front femora thickened; eyes contiguous below the antennae; 

palpi small, with an apical bristle; humeri constricted from the 

notum (16,18). Tachypeza. 

2. Front and middle femora thickened; middle femora with a double 

row of spines below; middle tibiae ending in a sharp spur; palpi 

broad . Platypalpus. 

Femora not thickened; middle legs without spurs and with minute 
or no spines; basal cells subequal. Symballophthalmus. 

3. First and second basal cells nearly equal; eyes widely separated; 

more or less pollinose species. ..... 4 

First basal cell much shorter than the second; eyes contiguous be- 
low the antennae; shining species. .... 6 

4. Arista dorsal; wings less than one-third the length of the abdomen. 

Thinodromia. 
Arista terminal or nearly so; wings surpassing the abdomen. 5 


EMPIDID^. 


223 


5. Antennae three-jointed: legs thick and bristly (8). Coloboneura. 
Antennae two-jointed; legs but little thickened and \vith few bris- 
tles Chersodromia. 

6. Arista dorsal; other characters as in Drapetis. . Stilpon. 
Arista terminal or subterminal. ...... 7 

7. Hnmeri not constricted from the mesonotum; thorax broader than 

the abdomen; second longitudinal vein short, and gently curved 
forward; the second and third sections of the costa subequal; 
palpi broad (19, 2O). ...... Drapetis. 

Humeri constricted from the mesonotum; thorax not broader than 
the abdomen; second longitudinal vein straight until near the 
end; palpi narrow. ..... 8 

8. Second longitudinal vein abruptly recurved at tip; second section 

of costa shorter than the third. . . . Phoneutisca. 

Marginal cell lengthened; second section of costa longer than the 

third. ........ Tachydromia. 

HEMERODROMIIN^B. 

1. Front legs raptorial, the front coxae and femora subequal in 

length; front femora and tibiae spinose below. ... 2 

Legs very slender and without spines; front coxae not greatly 

lengthened. .......... 3 

2. Third longitudinal vein simple; discal cell emitting three posterior 

veins; antennae with a long arista. . . . Chelipoda. 
Third longitudinal vein branched; antennae with a short style. 

Hemerodromia. 

a. Anal and discal cells present. ...... b 

Discal cell open. ........ c 

b. Second posterior cell pedunculate, subgenus Hemerodromia. 
Second posterior cell sessile. . subgenus Cladodromia. 

c. Anal cell wanting (15). . . subgenus Microdromia. 
Anal cross-vein present. ....... d 

d. Second posterior cell petiolate. . . subgenus Metachela. 
Second posterior cell sessile (26). . subgenus Neoplasta. 

3. Proboscis short, sharp and incurved; outer antennal joint conical, 

with a moderately long style; anal cross-vein perpendicular to 
hind margin of wing. ........ 4 

Proboscis vertical, usually soft; outer antennal joint short ovate, 
with a lengthened arista; anal cell usually rounded at tip. 5 

4. Second posterior cell petiolate. . . . Roederiodes. 
Second posterior cell sessile. .... Boreodromia. 


224 NORTH AMERICAN DIPTRRA. 

5. Third longitudinal vein simple. ...... 6 

Third longitudinal vein branched. ...... 7 

6. Anal cross-vein parallel with the hind margin of the wing (13). 

Oreothalia. 

Anal cross-vein perpendicular to the hind margin of the wing (6). 

Heleodromia. 

7. Head longer than broad, extending forward; wings brown with 

numerous pale spots. .... Dolichocephala. 
Head transverse, nearly vertical. .... Clinocera. 

BRACHYSTOMATIN^. 

Anterior branch of third vein terminates in the second vein (14) . 

Blepharoprocta. 
The anterior branch of the third vein terminates in the costa. 

Brachystoma. 

HYBOTIN^S. 

1. Fourth vein forked; hind femora slender. .... 2 
The discal cell emits two simple posterior veins; hind femora more 

or less thickened; antennae with a slender arista. . . 3 

2. Third longitudinal vein furcate; no antennal style (5, 1O) Prorates. 
Third vein simple; antennae with a thickened style. Megiiyperus. 

3. The second vein arises near the base of the wing (25) . Syneches. 
The second vein arises near the middle of ihe wing. . . 4 

4. Vein between basal cells indistinct. . Syndyas. 
Veins between basal cells strong (1, 21). . . . Hybos. 

OCYDROMIIN^;. 

1. Discal cell present. ......... 2 

Discal cell wanting. ......... 9 

2. The discal cell emits three simple posterior veins. ... 3 
First posterior vein obsolete; antennae with a long, slender arista. 8 

3. Third antennal joint short, ovate, pointed, with a long arista; third 

longitudinal vein simple. .... Parathalassius. 
Antennas with a short, thick style. ...... 4 

4. Third longitudinal vein furcate; last antennal joint short and broad. 

Hormopeza. 
Third vein simple. . ..... 5 

5. Hind femora spinose below, thickened; hind tibiae shortened, bow- 

ed near the knee; last antennal joint large. . Oedalea. 


EMPIDIM. 


225 


Hind legs slender and not spinose. ...... 6 

6. Last antennal joint short and broad, with a short, thick style; pro- 

boscis short. ....... Anthalia. 

Last antennal joint lanceolate or elongate cylindrical; its style 
short. ...... . 7 

7. Proboscis rigid, directed forward, about as long as height of head. 

Euthyneura. 

Proboscis short, fleshy, not directed forward. . . Trichina. 

8. Last antennal joint conical, arista terminal. . Leptopeza. 
Last antennal joint oval, arista subdorsal. (7) . Ocydromia. 

9. Fourth and fifth longitudinal veins weak, sometimes confluent ba- 

sally Bicellaria. 

All longitudinal veins strong, simple; hind metatarsi thickened; 
last antennal joint oval. .... Microsania. 


1. Third longitudinal vein simple. ...... 2 

Third vein furcate. ..... 5 

2. Proboscis not longer than height of head, porrect; outer antennal 

joint attenuated beyond the broad base and with an elongated 

style Microphorus. 

Proboscis longer than height of head; antennae plainly three- 
jointed. ..... .3 

3. Proboscis porrect; third antennal joint long and slender; its style 

minute. Anthepiscopus. 

Proboscis rigid, projecting down ward; third antennal joint conical. 4 

4. Face bare Rhamphomyia. 

Face hairy. NeOCOta. 

5. Metapleurae bearing a cluster of hairs or bristles. ... 6 
Metapleurae bare.. ........ 10 

6. Proboscis longer than height of head, rigid 7 

Proboscis short and fleshy (4). .... Oreogeton. 

7. First antennal joint elongate, third antennal joint subcylindrical, 

with a minute style; mesonotum without bristles; color metallic 

(17) Lamprempis. 

First antennal joint not elongate; third joint conical, with a longer, 
thickened style; mesonotum with bristles; color rarely metallic. 8 

22 


22 6 NORTH AMERICAN DIPTERA. 

8. Legs robust, all the femora of nearly equal length; males dichoptic. 

Pachymeria. 

Hind legs longer than the others, their femora but little thickened; 
males sometimes holoptic. ....... 9 

9. Face hairy (24). ...... Empimorpha. 

Face bare (22) Empis. 

10. Auxiliary vein short, recurved at its end to meet the costa; pro- 

boscis shorter than height of head; front metatarsi of male 
usually swollen (27). ...... Hilara. 

Auxiliary vein straight, extending to near the middle of the wing, 
evanescent at its tip so as not to meet the costa; male front me- 
tatarsi but rarely swollen. . . . . . . . ii 

11. Body and legs without bristles; the costal vein encompasses the 

entire wing. ......... 12 

Body and legs with bristles. ....... 13 

12. Proboscis much longer than head (2,9). . . . Toreus. 
Proboscis shorter than head (3, 11). . . Hesperempis. 

13. Proboscis porrect, about as long as height of head; palpi prom- 

inent ; nearly as long as the proboscis; third antennal joint 

nearly cylindrical, its style minute; hypopygium usually with 

a pair of dorsal processes; males holoptic. . Iteaphila. 

Proboscis shorter; males dichoptic. ..... 14 

J4. Third antennal joint short oval, with a rather short and thick 

style; proboscis horizontal (South America). Apalocnemis. 

Third antennal joint elongate; proboscis vertical. . . 15 

15. Femora more or less thickened; much longer than the tibiae; third 

antennal joint long, nearly cylindrical; thorax and legs with 

few bristles (South America). . . . Haplomera. 

Femora not thickened nor longer than the tibiae; third antennal 

joint conical. (South America.) . . . Hilarempis. 

Anthalia Zetterstedt, Ins. Lapp. (1838), 538. 
Anthepiscopus Becker, Wien. ent. Zeit. (1891), 281. 
Apalocnemis Philippi, Verh. k. k. zool.-bot, Gesellsch. , (1865), 752. 
Bicellaria Macquart, Soc. Sci. Agr. Arts. Lille, (1823), 155. 
Chelipoda Macquart, Soc. Sci. Agr. Arts, Lille (1823), 148. 
Chersodromia Walker, List. Dipt. Ins. Brit. Mus. iv, (1849), JI 57- 
Cladodromia Ann. Mus. Nat. Hung. (1905), 453. 


227 


Dolichocephala Macquart, Soc. Sci. Agr. Arts, Lille (1823), 147. 
Haplomera Macquart, Dipt. Exot., I, (1838), 279. 
Hesperempis Melander, Ent. News, (1906), 377. 
Hilarempis Bezzi, Ann. Mus. Nat. Hung. (1905), 443. 
Metachela Coquillett, Proc. Ent. Soc. Wash. V, (1903), 253. 
Microdromia Bigot, Ann. Soc. Ent. Fr. (1857), 557. 
Microsania Zetterstedt, Ins. Lapp. (1838), 534. 
Parathalassius Mik. Wien. ent. Zeit. X, (1891), 217. 
Prorates Melander, Ent. News (1906), 372. 

Symballophthalmus Becker, Wien. ent. Zeit. VIII, (1889), 285. 
Tachypeza Meigen, Syst. Beschr. VII, (1838), 95. 
Thinodromia Melander, Ent. News, (1906), 370. 
Toreos Melander, Ent. News, (1906), 376. 
Trichina Meigen, Syst. Beschr. VI, (1830), 335. 


XXVI. FAMILY DOUCHOPODID^. 

BY PROF. J. M. ALDRICH. 


Fig. 89. Psilopodinns sip ho, enlarged. After Lugger. 

Small flies, never exceeding 9 mm. in length, almost 
always green in ground color, usually shining, more 
rarely dusted with grey or brown, sometimes pure yellow 
or almost black. As a family they are distinguished 
from their nearest allies by the absence of the cross-vein 
between the discal and second basal cells, these uniting 
to form a single cell. 

Head about as wide as the thorax, usually a little 
wider than high; the face bare, varying much in width 
in different genera, in the females generally wider than 
in males of the same species; front widening rapidly above 
in nearly all genera (in Diaphorus the eyes sometimes 
contiguous on the front), with bristles on the vertex only. 
Posterior orbit with a row of short, erect bristles, indis- 
tinct below in some genera. Proboscis fleshy, short, re- 
tracted, or rarely a little protruding; palpi flat, reposing 

228 


DOLICHOPODID.E. 229 

on the proboscis in most species. Antennae three-jointed, 
inserted more or less above the middle of the eyes, close 
together, the first two joints always short: third joint 
commonly oval, but in several genera lengthened, some- 
times more so in the male; arista dorsal, subapical, or 
completely apical. Thorax in some genera with a well- 
marked flat or concave area in front of the scutellum on 
the dorsum. Abdomen conical or a little compressed, 
in Hydrophones and Scellus sometimes peculiarly small 
and retracted; hypogygium varying much in form in 
different species, generally rather conspicuous. Coxae 
generally short, legs in most genera of moderate length, 
in some elongate, those of the males frequently developed 
into some ornamental structure; the front femora are 
thickened in a few genera. Wings generally hyaline, yet 
often with dark markings, which may take the form of a 
definite pattern, or may follow the veins indistinctly, or 
may be evenly diffused. Anal cell always very short; 
two or three posterior cells; sixth vein always very short, 
sometimes absent. 

This family perhaps surpasses any other natural group 
of animals in the variety of secondary sexual characters 
possessed by the males. These are ornaments, and are 
paraded before the females, as are similar ornaments in 
the peacock and turkey-cock. They may occur in the 
tarsi, tibiae, femora, wing-apex, face, third joint of an- 
tenna, arista, palpi, and still other places. Contrary to 
the usual theory, these characters seem very constant, 
and are the main reliance in distinguishing the species. 
Identification in the family is rendered delightfully easy 
in the majority of cases, if one has the male. 

The larvae are almost wholly unknown in the United 
States; several species have been worked out in Europe. 
They are found in moist earth rich in decaying vegeta- 
tion, upon which they feed: Dr. A. D. Hopkins has 


230 


NORTH AMERICAN DIPTKRA. 


DOLICHOPODIM. 


231 


found larvae of Medeterus in burrows of Scolytidae, and 
thinks them predaceous. According to Sharp, the larvae 
are amphipneustic, 'a cocoon is formed and the pupa is 
remarkable on account of the existence of two long horns 
bearing the spiracles, on the back of the thorax; the seven 
pairs of abdominal spiracles being excessively minute.' 

In adult life all are predaceous, capturing chiefly the 
minuter soft-bodied flies, which they enclose within their 
soft labella, after the manner of Scatophaga, while ex- 
tracting the juices. 

As to their immediate habitat, Dolichopodidae are gen- 
erally very uniform within the species, but within the 
genus two or three habitats may be occupied. The fol- 
lowing list of places preferred is referred to by letter in 
the table of genera, and may be of use to collectors. 

a. On foliage in shady places. f. On stones in streams. 

b. On foliage in the sun. g. On bark of trees. 

c. On grass. h. On rocks in cold, wet places. 

d. On wet earth at edge of water. i. On sea beaches. 

e. On surface of water. j. On old logs. 

None of the species are attracted to flowers or to light. 

Fig. 90. Dolichopodidae. i, Psilopus unij'asciatus, wing; 2, 
Liancalus siwi/is, wing; 3, Psilopodinus sipho, wing; 4, Hypocharas- 
stts, gladiator, wing; 5, Diaphorus spectabilis, wing; 6, Plagioneurns 
nnivitattus, wing; 7, Xanthochlorns heli'inns, wing; 8, Achalcus n. 
sp. wing (22 diani.); 9, Asyndetus syntormoides, wing; 10, Tachytre- 
chus sanus, wing; 1 1, Sccllus I'i.gil, wing; 12, Hydrophorus eldora- 
densis, wing; 13, Nothosympycnusfrontalis, wing; 14, Pelastoneurus 
vagans, wing; 15, Gyinnopternus p'hyllophorns^ wing; 16, Argyra albi- 
citt/s, wing; 17, Mesorhaga albiciliata, wing; 18, Medeterus aurivit- 
tatus,wing', 19, Thrypticns unllistoni, wing; 20, Dolichopus tenuipes, 
wing; 2i, Xeurigona later alis, wing; 22, Parasyntormon montiva- 
guni, wing of male: 23, Sympycnus pugil, wing of male; 24, Rhaphi- 
11 in lugubre, wing; 25, Aphrosylus prcrdator, wing; 26, Hercostomus 
unicolor, wing; 27, Pelastoneurus vagans, head; 28, Rhaphium lu- 
gubre, head of male; 29, Porphyrops effilatus, antenna; 30, Hydro- 
phorus eldbradensis, head; 31, Pelastoneurus vagans, head of male 
from in front; 32, Mesorhaga albiciliata, head from in front; 33, Do- 
lichopus tcnuipes, abdomen of male, side v r iew; 34, Porphyrops effilatus, 
abdomen of male; 35, Dolichopus idahoensis, hind* metatarsus; 36, 
Nothosympvcnus fortunatus, front tibia and tarstis of male; 37, Scel- 
lus virago, front femur; 39, Parasyntormon emarginatum, antenna 
of male, inner side. 

All wings enlarged nine diameters, except fig. 8, where the corres- 
ponding size is shown in outline. Figs 36 and 39 after Wheeler, all 
others by J. M. Aldrich from nature. 


232 NORTH AMERICAN DIPTERA. 

TABLE OF GENERA. 

1. Fourth longitudinal vein with a widely divergent fork on the front 

side (1, 3) 2 

Fourth longitudinal vein generally without fork; if one is present 
it is parallel with the main vein. ..... 4 

2. Cilia of the tegulue black, third vein converging to the fourth at 

tip (3), scutellum with four large bristles (b) . Psilopodinus. 
Cilia of teguhe pale, third vein curving forward at tip (1), scu- 
tellum with two large and generally two small bristles. . 3 

3. Face wide, vertex deeply excavated (a). . . Psilopus.* 
Face narrow, vertex scarcely excavated. . Leptorhethum. 

4. Thorax almost as broad as long; head wider than its height or than 

the thorax; face wide, vertex deeply excavated (17, 32). 

Mesorhaga. 
Head and thorax not as described. ...... 5 

5. Fourth vein bent forward, forming an apical cross- vein; posterior 

cross-vein oblique, parallel with the margin of the wing (6, b) . 

Plagioneurus. 

Posterior cross-vein nearly transverse, usually no apical cross- 
vein. ...... 6 

6. Hincl metatarsi with large bristles above (35, a, b, d) . 

Dolichopus. 
Hind metatarsi without large bristles above. ... 7 

7. Hypopygium long, extending forward under the venter (33). 8 
Hypopygium short, not extending forward under the venter 

(34, one form). 20 

8. Arista plumose (27). ... ... 9 

Arista bare or pubescent. .... n 

9. Face wide, bulging on the lower part (27, 31, 14, a, d) . 

Pelastoneurus. 
Face narrow. .......... 10 

10. Third antennal joint of male large, elongated, excavated above. 

Leptocorypha. 
Third antennal joint normal, as in fig. 27. . . Sareionus. 

11. Before the scutellum the posterior third of the dorsum is hollowed 

out, or at least distinctly flattened 12 

Before the scutellum convex as usual. ...... 15 

* +l'o>iosonia of my Catalogue, 1905. 


DOLICHOPODIM. 233 

12. Posterior cross-vein distant much more than its own length from 

the margin of the wing (measured on the fifth vein, 19) . 13 
Posterior cross-vein distant about its own length from the mar- 
gin. ........... 14 

13. Second antennal joint prolonged along the inner side of the third. 

Cceloglutus. 

Second antennal joint not so prolonged, or forming a cup for the 
third (19, b, c) Thrypticus. 

14. Third and fourth veins parallel towards the tip (25, i). 

Aphrosylus. 
Third and fourth veins convergent (18, g) . . Medeterus. 

15. The face of the male extends far below the eyes, hanging down 

apron-like before the mouth (f ) . . . . Polymedoii. 

The face of the male reaches about as far as the lower edge of the 

eyes, head vertically elongated (1O, d, j). Tachytrechus. 

Face of the male reaching as far as the lower edge of the eyes, but 
the head not elongated. ..... Paraclius. 

Face of the male not reaching as far as the edge of the eyes. 16 

16. Third and fourth veins parallel towards the tip. . . . 17 
Third and fourth veins distinctly convergent. . . . 19 

17. Bristles of thorax yellow (19, b, c) . . . . Thrypticus. 
Bristles of thorax black. ....... 18 

18. First antennal joint bare above. . . . Peloropeodes. 
First antennal joint hairy above (15, a) . . Gymnopternus. 

19. The last segment of the fourth vein gradually approaching the 

third (26, a, c, d, e, h). . . . , Hercostomus. 
Last segment in the middle abruptly curving forward, then grad- 
ally resuming its former course, ending near the third vein. 

Paraclius. 

20. Costal vein extending only to the tip of the third vein, the latter 

part of the fourth vein evanescent (9, b) . . Asyndetus. 
Costal and fourth veins normal. . . . . . . 21 

21. First antennal joint hairy above. ...... 22 

First antennal joint bare above. ...... 26 

22. Fourth vein towards the tip strongly curved forward, nearly join- 

ing the third at the margin (14, 27, 31, d) . Pelastoneurus. 
Fourth vein parallel with the third, or slightly convergent. 23 

23. Arista dorsal, face very narrow, palpi small. . Anepsius. 


234 NORTH AMERICAN DIPTERA. 

Arista dorsal, face wide, palpi large. ..... 24 

Arista nearly or quite at the tip of the large, pointed third joint. 25 

24. Arista plumose Phylarchus. 

Arista pubescent (d) Diostracus. 

25. Posterior cross- vein distant about its own length from the end of 

the fifth vein (4, i). . . . . Hypocharassus. 

Posterior cross-vein much more than its own length from the end 

of the fifth vein (16, a, b, d) . .... Argyra. 

26. A concave or distinctly flattened bare space before the scutellum. 

27 
Thoracic dorsum convex as usual. . . . . . 31 

27. Bristles of thorax pale yellow (a) . . . Chrysotimus. 
Bristles black, rarely brownish. ...... 28 

28. Fourth vein parallel with the third beyond the cross-vein, or near- 

ly so ... 29 

Fourth vein converging towards the third (21, g). Neurigona. 

29. Acrostichal bristles present only at the anterior edge of the thorax, 

very mimite (7, a) Xanthochlorus. 

Acrostichal bristles well developed, two-rowed. ... 30 

30. Very minute, blackish, opaque species (8). . Achalcus. 
Small, yellow species Xanthina. 

31. Wings elongate, the posterior cross-vein beyond the middle, less 

than its length from tip of fifth vein (Hydrophorince}. 32 

Wings not elongate, posterior cross- vein scarcely beyond the mid- 
dle, more than its length from end of fifth vein; if less, the 
hind metatarsus shorter than the following joint. . . 34 

32. Fore femora slender (2, h) Liancalus. 

Fore femora thickened, with spines below (37, 38). . . 33 

33. Spines of fore femora very short, thoracic dorsum without well- 

marked pollinose lines (12, 38, d, e). . Hydrophorus. 

Spines of fore femora long, dorsum with pollinose lines (11, 37, 

c, g) Scellus. 

34. Chiter appendages of the hypopygium long and filiform, arista 

dorsal. Nematoproctus. 

Not with both characters 35 

35. Second joint of antenna with a thumblike projection along the in- 

ner side of the third (39) 3 6 

Second joint not with such projection. 37 


DOLICHOPODID^. 

36. Face of female wide, the lower part projecting roof like (a). 

Syntormon. 
Face of female not so constructed (22, 39, a) . Parasyntormon. 

37. Eyes of male contiguous or nearly so below the antennae. 38 
Eyes of male contiguous or nearly so above the antennae (5, a, b, 

c) Diaphorus, in part. 

Eyes closest together at the level of the antennas, middle legs of 

male distorted or with peculiar structure (c, d) . 

Campsicnemus. 
Eyes of male not contiguous nor closely approximated. . 41 

38. Abdomen of male with five visible segments besides the nearly 

concealed hypopygium (a, b, d). . Chrysotus, in part. 
Abdomen of male with six visible segments besides the hypopy- 
gium. . 39 

39. First joint of fore tarsiis in the male much shorter than the second 

(13, 36, a, c) Nothosympycnus. 

First joint of fore tarsus of male longer than the second. . 40 

40. Second longitudinal vein in the male strikingly sinuous. 

Eutarsus. 
Second vein almost straight (a) . . . . Sympycnus. 

41. Thorax bright green, abdomen yellow, with a good deal of silvery 

pollen (a) . Leucostola. 

Not so marked. ......... 42 

42. Face broad, the palpi large, reposing on the proboscis; pollinose 

species (d, i) Thinophilus. 

Palpi of ordinary size or else projecting lamelliform, free from the 
proboscis 43 

43. Third joint of antenna elongated in both sexes; in the male awl- 

shaped, not nmch wider at base than the first joint (28) . 

Rhaphium. 
Third joint elongated only in the male, lancet-shaped, much wider 

at base than the first joint (29, a). . . Porphyrops. 
Third joint short, the tip sometimes drawn out into a point. 44 

44. Abdomen of male with four blunt bristles at the tip (5, a, b, c) . 

Diaphorus, in part. 
Abdomen destitute of these bristles. ..... 45 

45. Arista nearly or quite apical (a, b, d) . Chrysotus, in part. 
Arista dorsal (d) Teuchophorus. 


XXVII. FAMILY PHORID^. 


BY C. T. BRUES. 

Small or minute species with a hunchbacked appear- 
ance. Head small, rather flattened; front broad in both 
sexes, usually bearing a few strong bristles; face very 
short, concave. Oral opening large; the proboscis usu- 
ally fleshy; the palpi projecting, large, generally with 
strong bristles. Eyes never very large, the ocelli always 
present in the winged^forms. Antennae with the third 
joint large and concealing the others, spheroid or pointed 
in shape, bearing a sub-dorsal or apical arista. Thorax 
usually large and arched, the scutellum rarely absent. 
Abdomen rather short, more or less narrowed behind, or 
oval, partly membranous in the wingless forms. Geni- 
talia of the male often large, of the female usually very 


Fig. 91. Phoridae. i, Puliciphora 9 ; 2, Aphiochccta, head; 3, Phora, 
antenna; 4, Conicem, antenna; 5, Aphioch&ta, wing; 6, Hypocera, 
wing; 7, Apocephalus, antenna. Drawings by Mrs. C. T. Brues. 

small and projecting. Ovipositor in Apocephalus and Plas- 
tophora hard, chitinized and projecting. Legs well devel- 

236 


PHORID^. 


237 


oped; coxae stout; femora large, the hind pair sometimes 
enlarged or flattened ; tibiae generally with a few strong 
bristles. Wings usually large, sometimes very small or 
entirely absent ; with two heavy veins anteriorly which 
reach only half way to the apex of the wing, and three 
or four much lighter ones, which run obliquely across the 

discaJ portion of] the wing. 

Flies belonging to this family can always be recog- 
nized by the peculiar antennae and wing venation. They 
are most frequently to be found about decaying vegeta- 
ble matter, fallen leaves, dead insects, on windows, or in 
ant nests. Some have been observed to frequent corpses. 

The larvae are cylindrical and tapering in front. The 
pupa is oval, distinctly segmented, and bears two slen- 
der projections from the fourth segment which form the 
breathing organs. These are connected with the pro- 
thorax. 

Their habits are extremely diverse. A number of spe- 
cies have been bred from decaying vegetables, fungi and 
other decomposing plant matter, while others feed on 
decaying caterpillars or other insects, as \vell as snails 
or other animals. A number live in ant nests, one (Apo- 
cephalus} as a parasite, and another (Metopina} as a com- 
mensal. In the case of the former the larva lives within 
the head of the adult ant, which finally drops off; while 
the larva of Metopina pachycondyla lives curled about the 
neck of its host ant-larva, partaking of the food given 
the latter by the attendant worker ants. Still others live 
in the nests of certain burrowing bees and wasps, and one 
is known to be parasitic on spider eggs. 

TABLE OF GENERA. 

1. Wings fully developed. ...... 2 

Wings absent, or much reduced in size and venation. . . 12 

2. Third longitudinal vein forked near the tip. ... 3 
Third longitudinal vein simple, at most thickened at tip. . 5 


NORTH AMERICAN DIPTERA. 

3. Costal vein and front destitute of strong setae. Gymnophora. 
Costal vein and front provided with strong setae. ... 4 

4. Anterior frontal setae reclinate, middle tibiae with one or more 

setae on the outer side near the base.j . . . Phora. 
Anterior frontal setae reclinate, middle tibiae destitute of such 

setae, ovipositor hard and polished. . . Apocephalus. 
Anterior!" frontal setae proclinate, middle tibiae destitute of such 

setae Aphiochseta. 

5. First longitudinal vein wanting. . . . Ecitomyia, male. 
First longitudinal vein present as usual. .... 6 

6. Anterior frontal setae reclinate, middle tibiae with one or more 

setae on the outer side near the base. .... 7 

Anterior frontal setae proclinate, middle tibiae without such setae. 9 

7. Velvet black, middle tibiae of the male with a row of long set?e on 

the upper side Trineura. 

Not velvet black, middle tibiae with only two or three setae besides 
those at apex. ......... 

8. Male antennae prolonged into a slender point with apical arista. 

Female antennae with a slight point where the arista is inserted 
at the upper corner, seventh vein obsolete. . Conicera. 
Third joint usually rounded in both sexes, seventh vein distinct. 

Hypocera. 

9. Spurs of four posterior tibiae wall developed. . 10 

Spurs of middle tibiae wanting, those of posterior pair minute, n 

10. Ovipositor of female prolonged, stout and thickly chitinized, ven- 

ation of wing normal. .... Plastophora. 

Ovipositor fleshy and retracted as usual, first and third veins 

strongly approximated, legs stout. . . . Syneura. 

11. Fourth, fifth and sixth veins light, seventh wanting; four trans- 

verse rows of frontal setae Metopina. 

Fourth, fifth, sixth and seventh veins strong; three transverse 
rows of frontal setae Puliciphora. 

12. Wings present, although of very small size. . . 13 
Wings completely absent. ..... 16 

13. Wings small, strap-shaped, often bearing long bristles. 14 
Wings larger, indistinctly veined, more or less triangular in shape. 

Commoptera, female; 


PHORID^E. 239 

14. Wings destitute of long bristles, abdomen without large macro- 

chaetae. Ecitomyia, female. 

Wings with very long bristles, head much wider than thorax, ab- 
domen often with large macrochaetae. . . . 15 

15. Head transversely arcuate, abdomen bare, wing bristles very long 

and stout Acontistoptera, female. 

Head sub-triangular, abdomen with many very long macrochaetae 
arranged in transverse rows. . . Xanionotum, female. 

16. Body when seen from above oval, cockroach-like, ^nigmatias. 
Body separated into the usual three parts, ocelli present. 

Puliciphora, female. 

NOTE No doubt much of interest awaits anyone who may under- 
take to study the varied habits of this interesting little family. 


XXVIII. FAMILY LONCHOPTERID^). 


Small (2-4 mm.), slender, brownish or yellowish flies. 
Antennae short, third joint rounded or globular, with a 
terminal bristle. Ocelli present; front bristly. L,egs 
long, bristly; pulvilli very small; empodia wanting. 
Wings lancet-like, pointed, the basal cells of small size 
and nearly equal length; fourth longitudinal vein fur- 
cate; first longitudinal vein short, second and third not 
furcate; the anterior cross- vein lies near the base of the 
wing, in front of the middle of the second basal cell, and 
is oblique in position. 


Xs^^xT^**^ 

Fig. 92. Lonchoptera, wing and head of female. 

There is but one genus in this singular family, Lon- 
choptera, the members of which may be found, often in 
large numbers, in the grass or upon stones along the 
margins of shady brooks. The larvae live under leaves 
and partially decomposed vegetable matter; they are 
flat, with long bristles on the first, second and last seg- 
ments; posterior spiracles broadly separated on the last 
segment, short and tubular; head not differentiated; the 
body composed of ten segments, the 1'ast one apparently 
formed of two. The larva transforms into a sort of semi- 
pupa within the last larval skin, and, later into a true 
pupa. The venation of the male differs from that of the 
female in the termination of the hindmost vein. 

240 


XXIX. FAMILY PLATYPEZID^. 


Fig. 93. Platypeza, species; enlarged. After Washburn. 

Small, thinly pilose flies, with bristles; especially char- 
acterized by the ornamentation or enlargement of the 
hind tarsi. Head hemispherical, as broad or broader 
than the thorax, and closely applied to it. Face usually 
short and broad. Eyes bare, contiguous in the male, 
and in some species in the female also. Ocelli present. 
Antennae porrect, the first two joints short, the third 
somewhat elongate, oval, pyriform or conical, with a 
terminal arista. Thorax rather stout, with distinct bris- 
tles; scutellum with bristles. Abdomen comparatively 
short; hypopygium more or less incurved. Legs short 
and strong; hind legs more or less thickened and the 
hind metatarsi thickened or variously ornamented in the 
American forms, the following joints often partaking of 


their peculiar structure. Wings rather large; third lon- 
gitudinal vein simple, the fourth sometimes imperfectly 
furcate; first posterior cell always open in the margin; 

241 


242 


NORTH AMERICAN DIPTHRA. 


basal cells small, the anal always longer than the second 
basal ; posterior cross- vein sometimes wanting. 

The flies of this small family have been seen dancing 
in the air in small swarms, or running about on the 
leaves of underbrush. The most remarkable thing about 
them is the oftentimes extraordinary ornamentation of 
the hind tarsi of the males, which are always different in 
structure from those of the females. The flies are not 
tften met with, and maybe entirely wanting even in con- 
siderable collections of diptera. Some, perhaps all pla- 
typezid larvae live in fungi (Agariciis, Lepiota, etc.). 
They are flat, oval, with jointed, thread-like processes 
on the sides of the segments. The puparia are not very 
different from the larvae. 


Fig. 94. Platypezidae. i, Platycnema^ wing; 2, Callimyia, wing; 
3, Callimyia, hind tarsus of male; 4, Platypeza, wing; 5, Platypeza, 
hind tarsus of male; 6, Calotarsa, wing; 7, Calotarsa, hind leg of 
male; 8, Agathomyia, antenna (Verrall). 


PLATYPEZID.E. 

TABLE OF GENERA. 

1. Discal cell open; fourth longitudinal vein not furcate; humeral bris_ 

tie conspicuous (1) . . . . ; . Platycnema 

Discal cell complete. ........ 2 

2. Fourth longitudinal vein furcate. ...... 3 

Fourth longitudinal vein not furcate. ..... 4 

3. Hind tarsi of male with ornamental appendages (6, 7) Calotarsa. 
Hind tarsi of male not with ornamental appendages (4, 5) . 

Platypeza. 

4. First longitudinal vein spinulose; third joint of antennae rather 

short (2, 3) Callimyia. 

First longitudinal vein not spinulose; third joint of antennae elon- 
gate conical (8). Agathomyia. 


XXX. FAMILY PIPUNCULID^. 


Fig. 95. Pipunculus fuscus, enlarged. After Lugger. 

Small, thinly pilose or nearly bare flies with large 
heads. Head nearly spherical, broader than the thorax, 
composed chiefly of the large eyes. Eyes of the male 
approximated closely or contiguous above; separated by 
the narrow front in the female. Face narrow. Antennae 
small, short, three-jointed, the third joint oval, reniform 
or aculeate, with a dorsal arista. Ocelli present. Pro- 
boscis small, concealed. Abdomen composed of six or 
seven segments, small, cylindrical; hypopygium thick- 
ened, more or less club-shaped; ovipositor usually elon- 
gate and folded under the abdomen. Legs simple ; 
metatarsi elongate, tarsi broad; tibiae without spurs; 
pulvilli present. Squamae vestigial. Wings much longer 
than the abdomen; basal cells large, the anal cell elon- 
gate, reaching to or nearly to the margin; first posterior 
cell narrowed in the margin, but never closed; three 
posterior cells; posterior cross- vein sometimes absent. 

The flies of this small family are commonly met with 
on flowers or in sweepings, and are readily distinguished 
by their large, subspherical heads. The larvae are para- 
sitic, so far as is known. Coheman has reared larvae of 

244 


PIPUNCULIM. 


245 


Pipunculus fuscipcs from Thamnotettix (Cicadula} virescens- 
They are elliptical, thick, depressed, narrowed at either 
end, naked and small. The puparia are somewhat small- 
er, oval, obtuse at either end, shining pitchy black. 
Chalarus spurius is said to be parasitic on a species of 
Typhlocyba. 


Fig. 96. Pipunculidse. i, Pipunculus, wing; 2, Pipunculus, head; 
3, Chalarus, wing; 4, Verrallia, wing; 5, Verrallia, head (Verrall). 

,X 

TABLE OF GENERA. 

1. Posterior cross-vein absent (3) . .... Chalarus. 
Posterior cross-vein present, the discal cell complete. . . 2 

2. No ocellar bristles; occiput excavated. ..... 3 

Ocellar bristles; occiput flattened; pilose species (4, 5). Verrallia, 

3. Thorax with well developed bristles; third antennal joint reniform 

(12, 13, p. So) Nephrocerus. 

Thorax not with well-developed bristles; third antennal joint more 
or less aculeate below; smaller species (1, 2) . Pipunculus. 


XXXI. FAMILY SYRPHID^B. 


97. Eristcitis tena.r. 

Enlarged one-half. 

After Kellogg. 


Small to rather large flies. Head 
hemispherical, often elongated or 
produced in the lower part; as broad 
or a little broader than the thorax. 
Face moderately broad, bare or cloth- 
ed with dust or short pile ; excavated 
in profile under the antennae and 
projecting below, or with a distinct 
convexity near the middle part, nev- 
er with longitudinal furrows or lat- 
eral ridges, usually convex trans- 
versely, sometimes with a median ridge. Oral opening 
large; proboscis rarely much elongated. Front never 
excavated. Antennae usually porrect and approximated 
at their base, three-jointed, usually with a dorsal arista. 
Eyes large, bare or pilose; in the male usually contigu- 
ous above. Ocelli always present. Thorax compara- 
tively large and robust, moderately arched above. Squa- 
mae of moderate size. Abdomen composed of five or six 
visible segments, rarely with only four. Hypopygium 
usually not prominent. Legs usually of moderate 
strength, never long. Bristles rarely present in any part 
of the body, never on the head; the body generally thinly 
pilose or bare, but sometimes clothed with thick pile. 
Wings comparativelylarge; third longitudinal vein never 
forked; marginal cell open or closed; the fourth vein 
terminates in the third at or before its tip ; three poste- 
rior cells; basal cells large; anal cell always closed be- 
fore the border of the wing ; between the third and fourth 
longitudinal vein and nearly parallel with them, a false 

246 


SYRPHID^E. 


247 


or spurious vein, nearly always present and characteristic 
of the family . 

The family Syrphidse is one of the most extensive in 
the order. About twenty-five hundred species are known 
throughout the world and new forms are constantly discov- 
ered. The}' contain among them many of the bright- 
est-colored flies, and numerous specimens are sure to 
appear in any general collection of insects. None are 
injurious in their habits to man's economy and many are 
beneficial. In their adult habits the}' all have a great 
uniformity. They are flower-flies and feed upon honey 
and pollen, loving the bright sunshine. 


Fig. 98. Jlfilesia virgin ieusis, enlarged. 

The larvae are usually not very elongate, with firm, 
sometimes tough skin, the head-segments small and ex- 
tensile, the head not distinctly differentiated. The ex- 
ternal mouth-parts are either wholly wanting, with only 
a soft fleshy opening, or there are two or four outwardly 


248 


NORTH AMERICAN DIPTERA. 


30 


3/ 


34 


35^ 


36 


40 


Fig. 99. Syrphidse. See page 251. 


directed booklets. Antennae short, small, one or two 
jointed and fleshy. Body smooth or provided with soft 
conical projections and bristles; below usually with seven 
pairs of abdominal feet. At the posterior end the body 
terminates in a more or less elongate tube, single or 
double, the stigmata. This tube sometimes forms a short, 
almost chitinized, tubercular projection on the dorsal 
part of the last segment; at other times it is very long, 
longer than the body, slender and composed of two joints, 
the one sliding within the other, like the joints of a tele- 
scope. In changing to the pupal condition, the larval 
skin contracts to form the pupal envelope, and the body 
becomes shorter, more oval and of a darker color, the 
elongated" respiratory tube, in the 'rat-tailed' species, 
being curved over the back. Unlike most other Cyclor- 
rhapha, the frontal lunule is not used in pushing off the 
cap to the puparium. 

The habits of the larvae are more variable than those 
of the adult flies. A large number live in decaying wood, 
or other vegetation, or in ordure, or decomposing animal 
remains. Some live in the stems of various plants, some 
in fungi. The larvae of many species of Syrphus and al- 
lied forms are aphidophagous, crawling about on the 
stems of plants frequented by plant-lice, and destroying 
them. Some live in ants' nests and may be parasitic; 
others in the nests of humble bees. 

Because of the large number of genera in the family, 
and the consequent length of the table, I give at the close 
an auxiliary grouping of the larger part of those genera 
which present decisive characters. By examining any 
specimen for the eleven characters given, and noting the 
agreement in numbers, the student may, in many cases, 
be more assured of his determinations. This family is a 
peculiarly difficult one to define clearly all the genera in 
a dichotomic table. I have introduced a number of cross- 
24 


references to such genera as may be doubtful to the nov- 
ice. Nearly all the genera, and many of the species will 
be found figured in the author's Synopsis. 

Several attempts have been made to subdivide the 
family into sub-families, but no proposed plan has re- 
ceived general approbation. I have recognized but three, 
the Syrphinse, Eristalinae and Cerinae. Verrall in his 
late attempt at classification has introduced several oth- 
ers, but not always happily. I cannot approve of such 
associations as Plants, Callicera, Chrysotoxum and Spheco- 
myia in the subfamily Chrysotoxin&i distinguished chiefly 
by the elongate antennae. Some species of Sphecomyia 
have very short antennae, notwithstanding which they 
show the closest relationship with the typical form. The 
length of the antennae is alwa} r s doubtfully a generic 
character even, and certainly cannot be used as a distin- 
guishing character for larger groups. 


Figs. 101, 102. Syrphidae. i, Microdon, sp. wing; 2, Chrysogaster 
nitida, wing; 3, Chrysogaster nitida, antenna; 4 Chrysogaster nig- 
ripes, antenna; 5, Paragus tibialis, wing; 6, Pipiza, sp., antenna; 7, 
Paragus tibialis, antenna; 8, Chilosia, sp., wing (spurious vein omit- 
ted). 9. Didea la.va, wing; 10, Didea la.va, antenna; u, Salpingo- 
gaster, sp., wing; 12, Volncella, sp. . wing; 13, I'olucella, antenna; 14, 
Copestyluni niarginatum, antenna; 15, Arctophilajlagrans,v{\ng\ 16, 
Sericoinyia militaris, antenna, 17, Eristalis, sp., wing; 18, Helophi- 
lus similis, wing; 19, Tropidia quadrata, hind leg; 20, Hfilesia vir- 
giniensis, hind leg; 21, Spilomyia longicornis, wing; 22, Spilomyia 
longicornis, antenna; 23, Ch r o sot ox u ;;/, species, antenna; 24, 
Sphvximorpha, sp., antenna; 25, Ferdiiiandea croesus, wing; 26, Voln- 
cella fasciata; 27, Myiolepta auricandata; 28. Syritta pipiens; 29, 
Xylota pigra; 30, Pipiza pulchella ; 31, Platycheirus hyperboreus; 
32, Syrphns americanus; 33; Sericomyia militaris; 34, Pterallastes 
(Triodonta] curvipes; 35, Scczva pyrastri\ 36, Tropidia quadrata; 37, 
Baccha lemur ; 38, Trichophthalmomyia, sp., 39, Baccha, sp.; 40, 
ApoJ>hysophora, sp. ; 41, Chrysotoxum^ species. 


25 2 NORTH AMERICAN DIPTERA. 

TABLE OF GENERA. 

1. Antennae with a terminal style. ...... 2 

Antennae with a dorsal (rarely subterminal) arista. . . 4 

2. Antennae cylindrical, the first two joints elongated; first posterior 

cell with a stiimp of a vein (24) (Ceria) . Sphyximorpha. 
First two joints of the antennae short. ..... 3 

3. Eyes bare; small species. ..... Pelecocera. 

Eyes pilose; larger species. ..... Callicera- 

4. Marginal cell of the wings closed and petiolate. ... 48 
Marginal cell open. ........ 5 

5. Anterior cross- vein of the wings distinctly before the middle of 

the discal cell; almost always rectangular. ... 6 

Anterior cross-vein near or beyond the middle of the discal ceil, 

usually oblique. . . . . . . . . -55 

6. Antennae elongate (if arista plumose, see 56). ... 7 
Antennae short. ......... 14 

7. Mesonotum with yellow lateral stripes; large species, the abdo- 

men always with distinct yellow bands (23, 41). 

Chrysotoxum. 

Mesonotum not with distinct yellow lateral stripes or margins. 8 

8. Face rounded, not tuberculate, pilose; oral margin not project- 

ing. . . 9 

Face not evenly arched; tuberculate or the oral margin project- 
ing. ........... 12 

9. Moderately large to large species; scutellum flattened, often with 

spines or tubercles on its border; a stump of a vein in the first 

posterior cell from the third longitudinal vein. . . 10 

Small species; scutellum without spines; no stump of vein in first 

posterior cell (3O). . Pipiza. 

10. Abdomen much narrowed at the base. . . . . .11 

Abdomen not or but little narrowed at base (1) . Microdon. 

11. Face swollen and prominent below. . Rhopalosyrphus. 
Face not swollen and prominent below. . . Mixogaster. 

12. Body clothed with sparse tomentum; all the femora thickened and 

with spinoiis bristles below (Lepromyia*} . Lepidostola. 

Body not clothed with flattened tomentum; the femora not thick- 
ened with spinoiis bristles below. ..... 13 

13. Face partly or wholly yellow, tuberculate below, the epistoma not 

projecting; face and front not wrinkled (5, 7). Paragus. 

* The name Lepidostola Mik has slight priority over Lepromyia. 


SYRPHIM. 253 

Front and face wholly black in ground color (Chrysogaster, Rhy- 
sops}. ........ . . 19 

14. Face black in ground color. . . . . . . .15 

Face more or less yellow or yellowish in ground-color. . 26 

15. Abdomen with only four visible segments, very convex, the venter 

excavated; first two joints of the antennae very short, the third 
large, subquadrate, with a short subterminal arista. 

Nausigaster. 
Abdomen with more than four visible segments. . . .16 

16. Hind femora distinctly thickened. .... .17 

Hind femora but little or not at all thickened. 18 

17. Scutellum unusually large, nearly square; males dichoptic. 

Chalcomyia. 

Scutellum not unusually large, considerably broader at its base; 
males holoptic and with a facial tubercle (27). Myiolepta. 

18. Face rounded, not tuberculate, the oral margin not projecting(SO) 

Pipiza. 
Face tuberculate or the oral margin projecting. ... 19 

19. Epistoma projecting; small, black species. .... 20 
Face tuberculate, the oral margin not projecting. ... 21 

20. Front in the female and usually the face in both sexes with trans- 

verse wrinkles; spurious vein obsolete; antennae short or long 

(2,3,4) Chrysog-aster. 

Front and face not wrinkled; face pilose. . . . Psilota. 

21. Metallic green, metallic green and black, or black species; facial 

orbits separated by a slender parallel groove (8). Chilosia. 
Black with more or less metallic green or blue, with yellow, yel- 
lowish or metallic cross-bands on the abdomen ; face not with 
orbital grooves. ......... 22 

22. Face with transverse grooves in the middle; (antennae elongate). 

Rhysops.* 
Face not with transverse grooves or wrinkles. ... 23 

23. Wings not longer than the abdomen; ocellar tubercle large; abdo- 

men depressed, long elliptical, somewhat narrowed toward its 
base, the markings ferruginous or orange yellow. Pyrophsena. 

* Melanostoma scitultim, rugonasus, melanocerum . 


NORTH AMERICAN DIPTERA. 

Wings longer than the abdomen, abdomen with yellow or green- 
ish-yellow, or shining metallic cross-bands ; usually elongate 
species. .......... 24 

24. Front tibiae distally and the tarsi of the male dilated, those of the 

female slightly widened (31). . . . Platycheirus. 
Front tibiae and tarsi slender in both sexes. .... 25 

25. Rather large, blackish species, with a large flat, elliptieal ab io- 

men. ...... Xanthandrus Verrall."* 

More elongate and slender species; abdomen not elliptical in out- 
line. . Melanostoma. 

26. Abdomen narrowed toward the base, distinctly club-shaped or 

spatulate in outline. ........ 27 

Abdomen oval or slender, not spatulate or club-shaped in out- 
line. ........... 30 

27. Third longitudinal vein bent deeply into the first posterior cell. (11) 

Salpingogaster, 
Third longitudinal vein straight or gently curved. . . 28 

28. Hind femora slender; front of female long, narrowed above; the 

cheeks very narrow below the eyes; abdomen often very slender. 

(37,39) ... Baccha. 

Hind femora thickened; front not unusually long in female. 29 

29. Epistoma produced anteriorly, the face in profile deeply concave 

from antennae to tip; third joint of antennae rounded. 

Sphegina. 

Epistoma produced more downward, in profile gently concave; 
third joint of antennae not rounded. . . . Neoascia. 

30. Front long, much narrowed above in the female; cheeks very nar- 

row, the eyes approaching each other at the lower third of the 
head; wings usually with dark picture; abdomen more or less 
elongate (compare Baccha when in doubt as to shape of abdo- 
men). ........ Ocyptamus. 

Flies not having the above assemblage of characters. . . 31 

31. Mesonotum with distinct yellow lateral margins. ... 38 
Mesonotum not with yellow lateral margins. ... 32 

32. Abdomen with definite yellow cross-bands. 33 
Abdomen not with definite yellow cross-bands. ... 42 

* Melanostouia bncephalus Wied. 


33. Hind femora extraordinarily thickened (28). . . Syritta. 
Hind femora slender. ........ 34 

34. Sixth abdominal segment in the male as long as the two preceding 

together, cylindrical; fifth segment of the female one-half as 
long as the preceding. ..... Eupeodes. 

Sixth abdominal segment of the male not peculiar; the fifth seg- 
ment of the female one-third or one-fourth as long as the pre- 
ceding. . 35 

35. Front very convex; eyes of male with an area of enlarged facets 

above (Lasiopticns (35). ..... Scaeva."* 

Front not remarkably convex. ...... 36 

36. Third longitudinal vein with distinct curvature into the first pos- 

terior cell; third joint of antennae elongate oval (9, 1O). Didea 

Third longitudinal vein straight or gently curved; epistoma not 

produced (if produced snout-like, Rhingia], ... 37 

37. Males holoptic (32) Syrphus. 

Males broadly dichoptic; arista more or less thickened. 

Chamsesyrphus. 

38. Mesonotum with median cinereous line; ocelli usually remote from 

the vertex. .......... 39 

Mesonotum not with a median cinereous linear stripe. . 40 

39. Hind femora in the male thickened and arcuate, the tibiae dilated 

at the tip Toxomerus. 

Hind femora simple and straight; the tibiae not dilated at tip. 

Mesogramma. 

40. Eyes of male with an area of enlarged facets above; fourth seg- 

ment of abdomen with two median yellow stripes and oblique 

side spots Allograpta.* 

Eyes of male not with an area of enlarged facets above; fourth 
abdominal segment not so-marked. ..... 41 

41. Face projecting below ; slender species, the hypopygium often 

large Sphserophoria. 

Face receding; abdomen oval. . . . Xanthogramma. 

42. Thickly pilose species; the abdomen black, the basal part light 

yellow. Leucozona. 

Thinly pilose species; abdomen not so marked. ... 43 

43. Hind femora thickened. ... ... 44 

Hind femora slender. ..... . 47 

' Feebly characterized genera. 


256 


NORTH AMERICAN DIPTERA. 


44. Species wholly or chiefly reddish or lutescent. ... 46 
Black species, sometimes with luteous spots on face, humeri and 

basal angles of abdomen. ....... 45 

45. Scutellum unusually large, nearly square in outline; males dichop- 

tic Chalcomyia. 

Scutellum oval; males holoptic (27). . . . Myiolepta. 

46. Face carinate; abdomen oval. .... Brachyopa. 
Face tuberculate; abdomen more elongate. Hammer schmidtia. 

47. Epistoma produced into a long porrect snout. . . Rhingla. 
Epistoma not produced (compare Paragus sp. if small); facial 

orbits limited by a slender groove (8). . . . Chilosia- 


48. Third vein bent deeply into the first posterior cell. . . 51 
Third vein not bent deeply into first posterior cell; third antennal 

joint elongate. ......... 49 

49. Arista very densely plumose, appearing as a solid mass, the arista 

itself also thickened (14) . .... Copestylum. 

Arista feathery plumose. ....... 50 

50. Hairs of arista retro rse; males dichoptic. . Megametapon. 
Hairs of arista not retrorse; males holoptic (12, 13, 36) . 

Volucella. 

51. Hind femora with a sharp tooth-like projection below near distal 

end; sixth vein beyond anal cell strongly curved; large species 

(2O) ... Milesia. 

Hind femora without such tooth. ...... 52 

52. Frontal triangle of male strongly protuberant; rather large, dark- 

colored species (Priomerus, Doliosyrphns.} . Eristalis. 

Frontal triangle not protuberant. ...... 53 

53. Epistoma produced into a long porrect snout. 

Licastrir hy ncha . 
Epistoma not produced. ....... 54 

54. Thorax with distinct yellow markings ; hind femora thickened; 

hypopygium enlarged. .... Meromacrus. 

Thorax not with distinct yellow markings, sometimes white-fas- 
ciate; femora sometimes thickened; hypopygium not conspicu- 
ously prominent (17). . . . Eristalis. 

o 

55. Arista plumose. ......... 56 

Arista bare or pubescent. ... .... 60 


SYRPHID^E. 257 

56. Antennae elongate, the third joint more than twice as long as wide 

(Phalacromyidi Glaurotncha] . . . . Volucella. 

Antemue short, the third joint not more than twice as long as 

wide; third vein nearly straight, or gently or considerably 

curved into first posterior cell. . ... 57 

57. Thinly pilose; abdomen with yellow bands. ... 58 
Thickly pilose; abdomen not with yellow bands. ... 59 

58. Third vein straight or moderately curved. . . Sericomyia. 
Third vein considerably curved.* . . . Condidea Coq. 

59. Eyes pubescent t ........ Pyritis. 

Eyes bare (15) Arctophila. 

60. Third longitudinal vein deeply curved into the first posterior 

cell. ........... 61 

Third vein only gently curved. ...... 70 

61. Hind femora thickened. ....... 63 

Hind femora slender. ........ 62 

62. Abdomen elongate, narrowed at base, spatulate in outline (11). 

Salping-ogaster. 

Abdomen oval, with yellow, interrupted bands; mesonotum with 
yellow margins; antennae elongate (22, 41). Chrysotoxum. 

63. Face carinate or subcarinate; hind femora with an angular pro- 

tuberance or spur below at outer end: 

Face protuberant in profile (19, 36) . . Tropidia. 

Face concave in profile, subcarinate; spur of femora bifid. 

Senogaster. 
Face tuberculate or arched, not keeled. .... 64 

64. Abdomen much narrowed at base, club-shaped. Ceriogaster. 
Abdomen not at all pedunculate or basally narrowed. . 65 

65. Antennae elongate; eyes pubescent; wings colored anteriorly. 

"Platynochaetus" niger.^% 
Antennae not elongate. ........ 66 

* This character is found in some of the species of Arctophila, Tro- 
pidia, etc., but is not considered generic. 

t Ocular pubescence alone is not of generic value; I do not know 
the genus. 

\ This is perhaps not a true Platynocluztus. The terminal expan- 
sion of the arista is a male character. I do not know it. 


258 


NORTH AMERICAN DIPTERA. 


66. Third joint of antennae broad; mesonotum not vittate. . 68 
Third joint of antennae oval. 

Males holopiic; femora with protuberance below. Merodon. 
Males dichoptic; femora not with protuberance. . . 67 

67. Ocelli remote from each other; mesonotum not vittate. 

Asemosyrphus . 
Ocelli not remote from each other; mesonotum vittate (18). 

Helophilus. 

68. Thickly pilose species. ...... Mallota. 

Thinly pilose. ......... 69 

69. Hind tibiae of male with an internal spur (compare Mallota, sp.) 

Teuchocnemis.* 

Hind tibiae of male not with such spur ( Triodonta, Polydonta] 
(34) Pterallastes. 

70. Thorax with distinct yellow markings other than on the humeril 

wasp-like flies. ,...* ^ ..... 81 

Thorax not with distinct yellow markings of the ground-color 

other than rarely on the humeri. . . . . . 71 

71. Hind femora swollen and with a protuberance or spur below dis- 

tally; face carinate or subcarinate. ..... 72 

Hind femora not with such protuberance or spur. . . 73 

72. Face concave in profile; femoral spur bifid. Senogaster.t 
Face protuberant in profile; femoral protuberance not spur-like 

(19,36) Tropidia. 

73. Abdomen narrowed basally; slender species (see 27). 
Abdomen in no wise club-shaped. ..... 74 

74. Face transversely arched, not produced, not tuberculate; abdo- 

men more or less elongate and nearly bare. 75 

More or less thickly pilose species; often large. ... 76 

75. Hind femora extraordinarily thickened; anterior cross-vein rec- 

tangular, and before the middle of discal cell (Syriila}. 
Hind femora distinctly thickened, but the cross-vein distinctly 
oblique, and near or beyond middle of discal cell. Xylota.+ 

* Of doubtful validity; I think that both this and Polydonta should 
be united with Pterallastes. 

t Of doubtful occurrence in the United States. 

% Xylota may be confounded with Brachypalpus. The nearly bare 
abdomen of the one, rather thickly pilose of the other, will distinguish 
them. 


259 

76. Scutellum, margin of thorax and pleurae with distinct bristles, 

femora slender (Chrysochlamys) (25). . Ferdinandea. 
No bristles anywhere on body. ...... 77 

77. Face short, not produced, concave from antennae to oral margin, 

not tuberculate; hind femora thickened. .... 78 
Face produced, long. ........ 79 

78. Abdomen elongate. Brachypalpus. 

Abdomen very broad ; thorax densely pilose ; middle femora of 

male sometimes (Hadromyid] with a stout, basal, inferior spur. 

Pocota. 

79. Face produced forward, pointed, concave from antennae to tip, not 

tuberculate; hind femora thickened. . . Crioprora.* 

Face not evenly concave in profile, but tuberculate or convex. 80 

80. Third joint of antennae produced above into an anteriorly directed, 

conical process, terminating in the thickened arista. 

Merapioidus. 

Third joint of antennae obliquely oval; hind femora rarely thick- 
ened. ......... Criorhina. 

Si. Hind femora with a conical, tooth-like protuberance below near 

distal end; antennae more or less elongated; sixth vein directed 

obliquely outward beyond anal cell (21, 22). Spilomyia. 

Hind femora without much protuberance; sixth vein beyond anal 

cell not unusual. ........ 82 

82. Antennae inserted low down, near middle of head in profile, the 

face not longer than front Temnostoma. 

Antennae inserted on a conical process; front short, the face 
much produced downward; antennae long or short. 

Sphecomyia. 

AUXILIARY TABLE. 

1. Marginal cell of wings closed: 

Copestylum, 4, 5, 8. Meromacrus, 2. 

Eristalis 2, (5), 8. Milesia, 2, 7. 

Lycastrirhyncha, 2, 6. (Priomerus), 2, 8. 

Megametapon 4, 5, 8, 10. Voluceila, 4, 5, 8. 

2. Third longitudinal vein markedly curved into first posterior cell. 
Asemosyrphus, 10. Arctophila, sp. 5, (fig. 15). 
Ceriogaster, 9. Platynochaetus, 13. 
Chrysotoxum, 4, 8. (Priomerus), i, 8. 
Condidea, 5. Pterallastes, 4. 

Didea, 8, (fig. 17). Salpingogaster, 9, (fig. n). 

Eristalis, i. 5, 8; (fig. 17). Syrphus, sp. 

Helophilus, 10, (fig. 18). Teuchocnemis. 

Lycastrirhyncha, i, 6. Tropidia, 7. 

Mallota, 8, TO. Milesia, i, 7. 
Meromacrus, i. 

* C. arctophiloides is a Criorhina, 


260 NORTH AMERICAN DIPTERA. 

3. First posterior cell with a stump of vein from the third longi- 

tudinal vein: 

Sphyximorpha, 4, n. Mixogaster, 4, 9. 

Microdon, 4, 8, (fig. i). Rhopalosyrphus, 4, 8, 9, 10. 

4. Antennae elongate: 

Sphyximorpha, 3, II, (fig. 24). Pipiza, 8. 

Chrysogaster, spp. (fig. 3). Platynochaetns, 2. 
Chrysotoxum, 2, 8, (fig. 4). (Phalacromyia), 5. 

Copestylum, I, 5, 9, (fig. 14). Rhopalosyrphus, 3, 8, 9, 10. 

Lepidostola, Rhysops. 

Megametapon, 5, 10. Sphecomyia, sp. 

Microdon, 3, 8. Spilomyia spp. 7. (fig. 23). 

Mixogaster, 3, 9. Volucella, i, 5, 8. 
Paragus, spp. 8. 

5. Arista plumose: 

Arctophila, 2. Megametapon, 4, 8, 10. 

Brachyopa, spp. Condidea, 2. 

Chilosia, spp. 8. Pyritis, 

Copestylum, i, 4, 8, (fig. 14). Sericomyia (fig. 16). 

Eristalis, spp. i, 2 (8). Volucella, i, 4, 8, (fig. 13.) 

6. Epistoma produced into a long, porrect snout: 
Rhingia, Lycastrirhyncha, 1,2. 

7. Hind femora with a projection below: 
Milesia, i, 2. Spilomyia. 4. 
Pterallastes, 2, .(sp.) 7. Tropidia, 2. 
Senogaster, 2, 9. 

8. Eyes pubescent: 

Chilosia, spp. Microdon, spp. 3, 4, 10. 

Chrysotoxum, 4. Paragus, 4. 

Ferdinandea. Pipiza, 4. 

Copestylum, i, 4, 5. Psilota. 

Didea, sp. 2. Pyritis, 5. 

Eristalis, spp. i, 2, 5. Rhopalosyrphus, 3, 4, 9, 10. 

Leucozona. Scaeva. 

Mallota, 2, 10, (sp). Syrphus, spp. 

Megametapon, i, 4, 5, 10. Volucella, i, 4, 5; or 4, 5. 

9. Abdomen spatulate or conspicuously narrowed at base: 

Baccha. Rhopalosyrphus, 3, 4, 8, 10. 

Ceriogaster, 2. Salpingogaster, 2. 

Mixogaster, 3, 4, 8, 10. Sphegina. 

Neoascia. Sphyximorpha, 3, 4, n. 

10. Males dichoptic: 

Asemosyrphus, 2. Mixogaster, 3, 4, 9. 

Chalcomyia. Megametapon, i, 4, 5, 8. 

Chamsesyrphus. Pelecocera, n. 

IJelophilus, 2. Rhopalosyrphus, 3, 4, 8, 9. 

Mallota, sp. 2, 8. Pterallastes, 2, 7, (sp.) 
Microdon, 3, 4, 8. 

11. Arista or style of antennae terminal: 
Callicera. Merapioidus. 
Pelecocera, 10. Sphyximorpha, 3, 4, 9. 


XXXII. FAMILY CONOPID^. 

Thinly pilose or nearly bare, more or less elongate flies, 
of moderate size. Head broad; front broad in both sexes; 
ocelli present or absent. Antennae porrect, the simple 
third joint with a dorsal arista or terminal style. Oral 
opening large; proboscis elongate and slender. Abdom- 
en often constricted toward the base; genitalia usually 
conspicuous. Basal cells of wing usually large, the 
anal closed; three posterior cells, the first closed or 
much narrowed; no spurious vein. An inflatable ptilin- 
um above the antennae. 

The members of this small family are all flower-flies, 
not of quick flight. Some have a remarkable resemb- 
lance to wasps, doubtless protective (see fig. 3, page 18). 
The genus Stylogaster is remarkable for the very long 
ovipositor of the female and the elongate proboscis of 
both sexes; the four or five known species are from Afri- 
ca, North and South America. The genus departs rath- 
er from the conopid type, with no essential differences 
from the Acalypterae. 

Some, perhaps all, of the larvae of this family are par- 
asitic upon adult hymenoptera (wasps and bees) and 
orthoptera. The eggs are deposited by the female, in 
some cases at least, directly upon the bodies of the bees 
or wasps during flight. The newly hatched larvae bur- 
row within the abdominal cavity of their host, and there 
remain, the hind end directed toward the base of the ab- 
domen, consuming the less vital parts, until ready for 
transformation into the adults, when they escape from 
between the abdominal rings of the insect. The larvae 
of the Conopinae are oval or pyriform, with distinctly 

differentiated segments, which may be extended or con- 

(25) 261 


262 


NORTH AMERICAN DIPTERA. 


CONOPIM. 263 

tracted. The antennae are wart-like, with a chitinous, 
ocellus-like ring on the extremity of each. The mouth- 
hooklets are strongly bent. On the last segment there 
are two large, round or reniform, stigmatic plates, arched 
like a watch crystal. The pupariuni is oval, with but- 
ton-like, slightly projecting, anterior stigmata, the post- 
erior pair as in the larvae; it remains within the body 
of the host during the winter. 

TABLE OF GENERA. 

1. Antennae with a terminal style; proboscis directed forward without 

median hinge; abdomen constricted toward the base. 2 

Antennae with a dorsal or subdorsal arista. . . -4 

2. Face with a median ke.el, without lateral grooves; a minute ocelli- 

gerous tubercle, the ocelli vestigial (4). . Tropidomyia. 
Face with well-marked divergent grooves. .... 3 

3. Femora and tibiae net thickened or dilated, or, if so, the thicken- 

ing is regular; anterior cross-vein nearly opposite or before the 
tip of the auxiliary vein, and near the middle of the-discal cell; 
ocelli functional or vestigial (1). . . . . Conops. 
Femora irregularly thickened toward the base, the tibiae with irreg- 
ular outlines; anterior cross-vein near outer third of discal cell; 
ocelli vestigial (2). .... Physocephala.. 

4. Proboscis directed forward, not hinged backward. (3). ZodiOD. 
Proboscis bent near middle, the distal part folding back. . 5 

5. Vertex with bristles; tibiae spurred; face carinate, not grooved; ovi- 

positor of female very long; anal cell small (8). Stylogaster. 
Vertex and tibiae without bristles; face with diverging grooves. 6 

6. Anal cell short; ovipositor elongate and folded beneath abdomen. 

(7) Dalmannia. 

Anal cell elongate, acute; ovipositor not folding beneath abdomen. 7 

7. Cheeks narrower than vertical diameter of eyes. ... 8 
Cheeks as broad or broader than eyes (6). . . Myopa. 

8. Antennae longer than the front (5). . . . Occemyia. 
Antennae shorter than the front. ..... Sicus. 

Fig. 101. Conopidae. 1, Conops xanthopareus, female; 2, Physocephala 
fiircill'ita, male; 3, Zodion fulvifrons, female; 4, Tropidomyia bimaculata; 5, 
Occemyia modesta, female; 6, Myopa clansu, female; 7, Dalmannia picta, fe- 
male; 8, Stylogastei' neglerta, female. 


XXXIII, XXXIV. FAMILIES MICROPEZID^, 

TANYPEZID^E. 


Fig. 102. Calobata univittata, enlarged. After Washburn. 

These two groups, often associated together, present 
such important structural differences, and the resem- 
blance of the insects composing them is so slight, that 
their separation seems entirely proper. 

Tanypezidce . Head broad, subhemispherical, the occi- 
put concave, the eyes very large, the posterior orbits very 
narrow, the cheeks also narrow; front rather narrow, 
with bristles on upper half only. No vibrissal bristle. 
Antennae more or less elongated, decumbent. Venation 
complete; posterior basal cells small; first posterior cell 
narrowed in the margin. Legs long; tarsi longer than 
the tibiae; tibiae without preapical bristle. 

A single genus Tanypeza, with a half dozen species 
perhaps, is all that can be definitely referred to this 
group. It will be readily recognized from the accompa- 

264 


MICROPEZID^ TANYPEZIM. 265 

nying figures (9, 1O) . A second genus, Tetr^adiscus 
Bigot, may possibly belong here, though it has the first 
posterior cell open and the third joint of the antennae 
rounded. The genus, if not identical with some other 
already known, can not be located until specimens are 
studied by some competent dipterist. 

Micropezidcz . Head subsperical; front rather broad, 
not bristly on the lower part. Kyes relatively small, the 
orbits and cheeks moderately broad. No oral vibrissae; 
face retreating in profile, sometimes very much so. Tho- 
rax narrowed anteriorly. Antennae short or moderately 
elongated, porrect. Abdomen elongate; male genitalia 
often large and complicated. Wings elongated; auxil- 
iary distinct in its whole course; or so closely applied to 
the short first longitudinal vein as to be distinguishable 
with difficulty. Anal cell always present, short, or drawn 
out into an acute point; second basal cell sometimes con- 
fluent with the discal cell; first posterior cell closed or 
much narrowed in the margin. Legs long and slender, 
the tarsi shorter than the tibiae; no preapical tibial 
bristle. 

So far as the known European and North American 
genera are concerned, the above diagnosis clearly defines 
the limits of the group. There are numerous forms in 
South America, however, which seem to break down the 
limits on the one hand from the Piophilidae, on the other 
from the'Ortalididse. The narrowing or closure of the 
first posterior cell is very distinctive of our species, but 
is net a group character. Nor are the slender legs a real 
'family' character, since there are southern forms with 
thickened hind femora and shorter legs which insensibly 
connect the more typical Calobattz or Micropeza, through 
Cardiacephala, with the Ortalididae. The group is dis- 
tinctively a South American one. The writer has more 
than a score of species in his collection from Brazil. 


266 


NORTH AMERICAN DIPTRRA. 


Fig. 103. Micropezidae, Tanypezidse. i, Neriits bistriatus, wing; 
2, Nerius, head; 3, Telostylus, antenna; 4, Calobata mellea, wing; 5, 
Micropeza, wing; 6, Micropeza antenna; 7, Cardiacephala, head; S* 
Cardiacephala, hind leg; 9, Tanypezaclaripennis, head; 10, Tanypeza, 


wing. 


TABIvK OF GENERA. 

1. Second basal cell confluent with the discal cell (5, 6) . Micropeza. 

Second basal cell complete. ....... 2 

2. Third antennal joint truncate at the tip, with a terminal bristle 

(1, 2). . . . . . . . . . . Nerius. 

Third antennal joint tapering to a point, into which is inserted 

the apical, pubescent arista (3) . . Telostylus Bigot. 

Arista distinctly dorsal, that is nearer the base of the third joint 

than its tip; wings usually with markings. ... 3 

3. Auxiliary vein distinct; femora simple (4). . . Calobata. 
Auxiliary vein indistinguishable; posterior femora with a swelling 

beyond the middle (7, 8) Cardiacephala. 


XXXV. FAMILY 

Front bristly on the upper part; broad. Face perpen- 
dicular or somewhat retreating in profile, without vibris- 
sae. Antennae moderately or very long, decumbent. 
Abdomen rather slender; male genitalia but little prom- 
inent, the ovipositor usually elongate. Wings large; 
auxiliary vein absent or indistinct; third and fourth 
longitudinal veins parallel ; all three basal cells distinct. 
Legs elongate: no preapical bristle on the tibiae. 

The flies of this family are of moderate size and elon- 
gate. The larvae of those few species in which they are 
known live in the roots or galls of different plants. The 
larvae of Psila are slender, cylindrical, pale yellow, bare; 
the posterior stigmata are small, rounded or button-like 
processes of a black color. 


Fig. 104. i, Loxocera; 2, Loxocera, head; 3, Chyliza, wing; 

4, Chyliza, head. 
267 


268 


NORTH AMERICAN DIPTERA. 


The occurrence of Megamerina Rondani in America 
lacks confirmation. It has the auxiliary very distinct 
and probably belongs more properly with the Sepsidse. 

TABLE OF GENERA. 

1. Antennae much elongated, the third joint slender (1, 2). 

Loxocera. 
Antennae shorter than the face, the third joint oval or rounded. 2 

2. Face nearly perpendicular in profile; anal cell noticeably shorter 

than the second basal cell (3,4). . . . Chyliza. 

Face retreating in profile; anal cell as long or longer than the sec- 
ond basal cell. . .... Psila. 


Fig. 105. Sepsidae. i, Sepsis, wing; 2, Sepsis, head; 3, Sepsis, 
front leg; 4, Prochyliza, head; 5, Piophila, wing; 6, Piophila, head; 
7 Michogaster, head (S. A.); 8, iMichogaster, wing. 


XXXVI. FAMILY 


Fig. 106. Piophila casei, enlarged. After Washburn. 

Head rounded; front bristly above; face perpendicular 
or a little retreating ; border of the mouth more or less 
hairy, with or without vibrissae ; proboscis short ; anten- 
nae not porrect, usually short. Abdomen usually notice- 
ably narrowed at the base; hypopygium prominent. 
Auxiliary vein distinct or more or less coalescent with the 
first vein; all the basal cells distinct. Middle tibiae with 
spurs; tibiae usually without preapical bristle. 

The flies of this family are usually small, black and 
elongated, with the abdomen narrowed at the base, thick- 
ened and curved downward toward the extremity; with 
transparent, irridesceut wing, usually hyaline, but often 
with a spot or spots toward the end, and are usually ob- 
served about decaying vegetables, excrement, cheese, 
ham, etc., often in swarms. The flies for the greater part, 
run about actively and are quick in flight. The best 
known are the species of Piophila, the larvae o-f which are 

269 


270 NORTH AMERICAN DIPTERA. 

so well known as 'cheese-mites'. These larvae live in 
cheese, in ham or bacon, or in general in any fatty ma- 
terial, and often do much damage, being especially 
troublesome in pork-packing establishments. From the 
peculiar power of leaping possessed by the maggots they 
are often called 'skippers' ; the act is performed by the lar- 
va seizing with its extended mouth-hooklets the edge of 
the posterior truncature of the body and then suddenly 
releasing it while pulling hard. The larvae are some- 
what conical, pointed anteriorly, truncated behind, and 
about five millimeters in length. They are shining and 
smooth; the antennae composed of two equally long joints; 
the mouth hooklets separated, short and divergent; the 
anterior spiracles w T hitish, the abdominal legs roughened, 
the anal segment wath four fleshy protuberances. Pupa- 
rium elliptic, rugose. 

TABLE OF GENERA. 

1. Head depressed; antennae elongate. ..... 2 

Head not depressed; antennae not reaching beyond the oral mar- 

y 111. * X 

2. Second joint of antennae elongate, the third oval (4) . Prochyliza, 
Second joint of antennae short, the third elongate. Tylomyia 

3. Auxiliary vein distinct; palpi vestigial. ..... 4 

Auxiliary vein indistinct, or wanting. ..... 6 

4. Abdomen curved, narrowed at base, the second segment swollen. 5 
Abdomen straight or but slightly curved, biit little narrowed at 

base, the second segment not swollen. . . Themira 

5. Front femora of male with tubercles on under side (1, 2, 3) . Sepsis. 
Front femora of male not with tubercles on under side. 

Nemopoda. 

6. Wings with blackish spot at tip; antennae reaching nearly to the 

oral margin Mycetaulus. 

Wings wholly hyaline; antennae shorter (5, 6). . Piophila. 


XXXVII. FAMILY 


Fig. 107. Antineura, sp. Brazil. Enlarged. 

Rather small to moderately large flies. Front broad in 
both sexes, never with lower fronto-orbital bristles. Vi- 
brissae wanting. Clypeus distinct, usually well devel- 
oped; proboscis more or less stout; palpi broad, seldom 
narrow. Abdomen with five segments in the male, six 
in the female, the first two in both sexes more or less 
coalescent ; male with a rolled up, long penis; female 
with a three-jointed, horny ovipositor. Legs usually 
stout and short, never very slender. Venation of wings 
complete; auxiliary vein usually completely separated 


271 


272 


NORTH AMERICAN DIPTERA. 


Fig. 108. 


ORTALJDID^ 


Figs. 108, 109. Ortalididae. i, Pyrgota; 2, Stenopterina; 3, Camp- 
toneura ; 4, Idana ; 5, Rivellia ; 6, Tetanops; 7, Pseudotephritis; 
8; Oedopa; 9, Cluctopsis; 10, Ctflouietopia; n, Pterocalla; 12, Melie- 
ria; 13, fcntnciopia; 14, Richardia; 15, Euxesta; 16, Euxesta; 17, 
Notogramma; 18, Euphara; 19, Antineura; 20, 6-Vw. nov ? 21, 
ApGSpasmica; 22, Stenomacra. 

from the first longitudinal vein, though often much ap- 
proximated to it; it runs into the costa at a more or less 
acute angle, without becoming indistinct at its end; pos- 
terior basal and anal cells of moderate size, the latter ex- 
ceptionally indistinct. Middle tibiae alone provided with 
spurs; tibiae rarely with an erect bristle before the tip 
exteriorly ( Automata ) . 

The present family includes a large number of species 
of flies that are sure to be represented in every collection 
26 


971 NORTH AMERICAN DIPTERA. 

274 

of diptera. Many of the species have the wings prettily 
marked. The family by some entomologists is divided 
into several independent groups, as the Doryceridse or 
Pyrgotidse, the Platystomidae, Ulidiidae, etc. The flies 
are usually found about meadows or among luxuriantly 
growing grass. The larvae are but poorly known. 

TABLE OF GENERA. 

BY PROF. W. A. SNOW; REVISED. 

1. First longitudinal vein beset with small bristles. ... 2 
First longitudinal vein bare. ....... 5 

2. Ovipositor flattened; ocelli present. ..... 3 

Ovipositor not flattened; no ocelli. .... Pyrgotinae. 

3. Third antennal joint round or short ovate; ends of auxiliary and 

first longitudinal veins widely separated. . Pterocallinge. 
Third antennal joint not round or short ovate.* ... 4 

4. Neither pro-pleural nor meso-pleural bristles present; third anten- 

nal joint elongate. ..... Platystominse. 

A meso-pleural but no pro-pleural bristle present. Cephalinse. 
Both a meso-pleural and a pro-pleural bristle present. Ortalinse. 

5. Posterior angle of anal cell drawn out into a lobe, or at least, more 

or less acute; femora never armed. . . . Ulidinae. 

Posterior angle of anal cell obtuse; rounded or retracted; femora 

armed in mo^t of tha genera. . . . Richardiinge . 

PYRGOTIN^. 

Front strongly projecting; face retreating; oral opening small; pro- 
boscis not incrassated; clypeus but little developed; ocelli absent; no 
pro-pleural bristle; first longitudinal vein hairy; ovipositor not flat- 
tened (1). ......... Pyrgota. 


Oral opening very large; clypeus generally very much developed, 
and the proboscis proportionately stout; third antennal joint elongate; 
mesonotum bristly on the hind part only; pro-pleural and meso-pleu- 
ral bristles absent; female abdomen with five segments; ovipositor 
flattened; first longitudinal vein bristl)*. 

* Tetropismenus L/oew has the third antennal joint circular, but its 
short stigma or subcostal cell locates it among the Ortalinae. 


ORTALIDIM;. 


275 


i. The picture of the wings consists chiefly of a dark border along the 
costa, from the base of the stigma to the tip of the wing, with 
the first basal cell and the posterior cross-vein clouded; anterior 
cross-vein oblique. ........ 6 

Flies not having the above characters. ..... 2 

2. Posterior angle of the anal cell drawn out into a sharp point. 

Ostracoccelia. 
Posterior angle of the anal cell rounded. ..... 3 

3. Picture of the w T ings dark, varied with transparent spots and bars. 4 
Wings not so marked. . ...... 5 

4. Scutellum large, flat; occiput but little swollen ; veins of wings 

straight and markedly divergent. . . Amphicnephes. 

Scutellum smaller, not flattened; occiput much smaller; epistoma 

strongly projecting; third and Jourth longitudinal veins nearly 

parallel, sinuous. ...... Platystoma. 

5. The picture of the wings consists of four blackish cross-bands, of 

which the third is nearly perpendicular, and the fourth lies 
along the costa at the apex of the wing; scutellum with four 
bristles (5) ......... Rivellia. 

Wings without bands; scutellum with two bristles; ant-like flies. 

Myrmecomyia. 

6. Posterior cross-vein prolonged beyond the fourth vein; scutellum 

with six bristles, ...... Himeroessa. 

Posterior cross-vein not prolonged. ...... 7 

7. Fifth longitudinal vein bristly. .... Briciniella. 
Fifth longitudinal vein not bristly;* scutellum with four bristles (2) . 

Stenopterina. 


Oral opening very large; clypeus and proboscis greatly developed; 
propleural bristle absent; mesopleural bristle present; sixth segment 
of the abdomen in the female distinctly developed; ovipositor flatten- 
ed; first longitudinal vein bristly. 

i. Slender, Sepsis-like flies, resembling Myrmecomyia, with wings 
almost hyaline, except for a small infuscation at the stigma and 
at the tip ......... Cephalia. 

Wings with a conspicuous picture. ...... 2 

* I can not see wherein Bricinnia Walker, to which Giglio-Tos re- 
fers a Mexican species, differs from Stenopterina. 


276 NORTH AMERICAN DIPTERA. 

2. Wings dark, with three oblique, more or less arcuated, hyaline 

cross-bands; first basal cell expanded before its end. Tritoxa. 
Wings not with such markings. ...... 3 

3. Wings broad, with a marked excision on the costa near the end of 

the auxiliary vein; second vein sinuous (3). Camptoneura. 
Flies not having such wings. ....... 3 

4. Posterior angle of the anal cell retracted (4) . . . Idana. 
Posterior angle of the anal cell drawn out into a long hole. 

Diacrita. 


The Ortalinae differ from the Platystominae and Cephalinae in the 
usually small oral opening, the less developed clypeus, more slender 
proboscis and smaller palpi. The mesonotum is sometimes bristly in 
the middle anteriorl)', the propleural and mesopleural bristles both 
present. Female abdomen with ix segments. 

1. Face sharply carinate. ........ 2 

Face not sharply carinate. ....... 3 

2. Third antennal joint circular; hairy species. Tetropismenus. 
Third antennal joint ending in a sharp point; pollinose flies. 

Tephronota. 
Antennae nearly as long as face, rounded at tip; mouth large. 

Hiatus.*. 

3. Mesonotum bristly in the middle in front; third antennal joint ex- 

cised above and with a pointed tip (12). . . Melieria. 
Mesonotum not bristly in the middle in front. ... 4 

4. Third antennal joint distinctly excised above, pointed at the tip; 

fourth longitudinal vein with a marked anterior curvature on its 
distal part. ....... Anacampta. 

Third antennal joint not excised above; fourth vein not so curved. 5 

5. Tibiae with preapical bristle,. . . . . . Automola. 

Tibiae without such bristle. ..... Tetanops. 


Trypeta-like; coloring nonmetallic; head rather broad, but low, w T ith 
rather protuberant eyes; face short, perpendicular, excavated in the 
middle; clypeus but little developed; third antennal joint round or 
short oval; mesonotum bristly upon the posterior part only; first longi- 
tudinal vein and auxilary vein remote from each other at tip; poste- 
rior angle of the anal cell often drawn out into a long lobe. 

* Cresson. Trans. Amer. Ent. Soc. xxxii, 286. 1906. 


1. Posterior angle of anal cell drawn out into a long lobe; posterior 

cross-vein very oblique. ....... 2 

Posterior angle of anal cell not greatly produced. ... 3 

2. Wings proportionately narrow, of equal width; round at tip (11) . 

Pterocalla. 
Wings with much curved hind margin. . . Callopistria. 

3. Anterior and posterior cross-veins very oblique. ... 5 
Posterior cross-vein rectangular or nearly so. .... 5 

4. Scutellum with two bristles. .... Xanthachrona. 
Scutellum with four bristles. ..... Myennis. 

5. Second longitudinal vein straight or nearly so; anterior cross-vein 

not oblique. ......... 6 

Second longitudinal vein markedly sinuous ; cross-veins approxi- 
mated and the anterior one very oblique. Paragorgopis.* 

6. Cheeks rather broad; posterior angle of anal cell acute (7). 

Pseudotephritis. 

Cheeks and face extremely short; eyes transversely oval; posterior 
angle of anal cell rectangular. . . . Psairoptera. 

UI^IDIIN^S. 

Head large, hemispherical, proboscis stout, with broad labella; front 
broad; antennae usually short; mesonotum bristlv in the middle behind 
only; first and third longitudinal veins of the wing bare; posterior an- 
gle of the anal cell acute, sometimes drawn out into a long lobe. 

1. Head conspicuously large; antennae widely separated at base; 

cheeks and face swollen. ....... 2 

Head not conspicuously large; antennae not unusually remote at 

I ''i"* 1 ' . ).& 

2. Eyes round, about one-half the height of head. ... 3 
Eyes higher than long Parcedopa.f 

3. Third joint of antennae rounded; front not rugose above (8). 

Oedopa. 
Third joint of antennae elongate; front rugose above. Eurycephala 

4. Antennae long; third joint unusually long. . Stictomyia.t 
Antennae shorter, the joint more or less oval. ... 5 

* This genus is located here as definitely as the characters given will 
permit. 

t These genera are inserted after Cresson, 1906, 7. 


278 NORTH AMERICAN DIPTERA. 

5. Posterior angle of anal cell acute, but scarcely prolonged lobe-like. 

12 
Posterior angle of anal cell distinctly drawn out into a lobe. 6 

6. Front punctate or scrobiculate.* 7 

Front smooth. . . ....... 10 

7. Scutellum flat, with sharp edges; fourth longitudinal vein strongly 

curved forward at its distal end; front coarsely rugose. . 9 
Scutellum convex, rounded on its edges. .... 8 

8. Stigma not unusually elongate. , Ulidia. 
Stigma elongate, about as long as the costal cell. Acrostic ta. 
Wings with cross-bands (18) Euphara. 

9. Third antenna! joint elongate (17) . . . Notogramma. 
Third antennal joint not elongate. . . . Chrysomyza. 

10. Face distinctly projecting below; third antennal joint roimded at 

the end. . . . . . . . . .11 

Face retreating; third antennal joint with a sharp anterior angle. 
(9) . . . Chsetopsis. 

11. Third antennal joint twice as wide as long. . . Zacompsia. 
Third antennal joint not twice as wide as long (16.) Euxesta. 

12. Body extremely slender. ....... 13 

Body not slender; face carinate. .... Seoptera. 

13. Front only slightly "projecting in profile; face oblique. 

Stenomyia. 

Front very much projecting, so that the head is conical and the 
face nearly horizontal (13) Eumetopia. 

RICHARDIIN^S. 

Mesonotum with bristles in the middle posteriorly only; femora 
often armed and incrassate; first longitudinal vein bare; posterior an- 
gle of the anal cell obtuse; costal vein usually broken just before the 
termination of the auxiliary vein; auxiliary and first longitudinal 
veins closely approximated, their tips near together. 

i . Femora all armed with spines. ...... 3 

Front and hind femora only, with spines. . . Sepsisoma. 
Front and middle femora unarmed. ..... 2 

All the femora unarmed. ........ 5 

* Smooth in Acrostic fa bicolor Cresson. 


ORTALIDIM;. 279 

2. Hind femora incrassate (14). .... Richarula. 
Hind femora not incrassate. ..... Paneryxna. 

3. Scutellum with two bristles. ....... 4 

Scutellum with four bristles; ocelli remote from the vertex; last 

section of the fourth vein convergent toward the third (1O) . 

Ccelometopia. 

4. Ocelli approximated to the vertex; front not narrowed anteriorly. 

Neoidiotypa. 

Ocelli remote from the vertex; front somewhat narrowed ante- 
riorly; wing narrowed at base (22) . . . Stenomacra. 
Front projecting; wings not narrowed at base. Cyrtometopa. 

5. Head shaped like a long, somewhat flattened cone. Coniceps. 
Head not so shaped. ........ 6 

6. Wings but little developed; anal cell wanting. Steneretma. 
Anal cell present; wings fully developed. . . Epiplatea. 


XXXVIII. FAMILY RHOPALOMERID^. 

Front broad, excavated, with or without short orbital 
bristles. Antennae short, third joint rounded or oval, the 
arista bare or plumose. Face broad, carinate, tubercu- 
late or the oral margin prominent; cheeks broad; clypeus 
projecting; vibrissse wanting; proboscis short; palpi 
slender or dilated. Thorax elongate, arched, mesonotum 
nearly bare; scutellum often prominent and grooved. 
Abdomen shorter than the wings, flattened; ovipositor 
projecting, telescopic; hypopygium largely concealed. 
Femora thickened, the hind tibiae often dilated. Auxil- 
iary vein present or absent; basal cells well developed. 


Fig. no. Rhopalomeridse. i, Willistoniella, head from in front; 
2, Apophyrhynchus, head; 3, Rhopalomera^ wing. 

This group comprises a small number of flies from six 
to twelve millimeters in length, of peculiar aspect, hav- 
ing a general resemblance to some of the Kphydridae or 

280 


RHOPALOMERIM). 28 1 

Sapromyzidse. I know nothing of their habits, whether 
in the adult or immature stages, though I suspect that 
they are denizens of wet or damp places. The known 
species are confined to Central and South America. 

The group is evidently sharply divided into two minor 
groups, by the presence or absence of the auxiliary vein 
and the length of the first longitudinal vein. 

TABLE OF GENERA. 

1. Auxiliary vein wanting, the first longitudinal vein short; first pos- 

terior cell of the wings not narrowed; palpi slender (Rhinoto- 
rincs} ......... Rhino to ra. 

Auxiliary vein well-developed, the first longitudinal vein longer; 
first posterior cell much narrowed in the margin; palpi dilated 
{Rhopalomerince) . ........ 2 

2. Scutellum oval; arista plumose. ...... 3 

Scutellum pyramidal, directed obliquely upward; arista plumose or 

bare (3, 7, p. 34) Rhopalomera. 

3. Front with bristles; face carinate; hind tibiae dilated and with tuber- 

cles (1) Willistoniella, Mik. 

Front without bristles; face tuberculate; hind tibiae slender (South 
America). . . . Apophorhynchus Williston. 


XXXIX. FAMILY TRYPKTID^). 


Fig. in. Straussia longipenms, enlarged. After Kellogg. 

Head hemispherical; face nearly vertical in profile, or 
somewhat retreating, without distinct vibrissae. Front 
broad, bristly on the sides, the lower fronto-orbital bris- 
tles situated close to the border of the eyes. Antennae 
decumbent, short, rarely elongated. Abdomen composed 
of four or five segments; genitalia of the males but little 
exposed; the ovipositor jointed, more or less projecting, 
Wings rather large ; auxiliary vein present, ending steep- 
ly and obscurely in or near the border; posterior basal 
cell and the anal cell distinct, the latter often drawn out 
into an acute, often prolonged, point. Wings usually 
with dark markings. Legs moderately long; tibiae with- 
out preapical bristle. Proboscis moderately long, usu- 
ally with broad labella; sometimes long, and the narrow 
labella folding backwards. 

This family comprises a large number of rather small 
flies usually with prettily marked wings. The larvae are 
not elongate, conical and round ; the posterior stigmata 
lie free in two separated small, chitinous platelets, form- 
ing three radiating depressions; antennae short, two- 
jointed; mouth booklets separated, thick and strong; 

anal end somewhat impressed, often in the middle with 

282 


TRIPETID^. 


283 


six small; fleshy points. Puparia elliptical; the anterior 
stigmata projecting somewhat buttonlike. The larvae of 
Ceratitis live in the flesh of oranges and lemons, those of 
Aciura have been found at the base of the flower stems of 
Phlomis, those of Adda mining in the leaves of Rumex, 
those of Spilographa mining in the leaves of Senecio, or 
Arctium or bred from the berries of Solanum carolinensis , 
in the fruit of Prunus and Lonicera, etc.; those of Ensina, 
in the blossoms of Senchus; those of Tephritis in the blos- 
soms and galls of the stems or roots of various compositae; 
those of Carphotricha in the galls and roots of Achillea, 
the flowers of Hieracium, etc.; those of Trypeta in the 
heads of Cirsium, Centaurea, etc., and in stems of plants. 

TABLE OF GENERA. 

1. Ovipositor of female remarkably elongated; second longitudinal 

vein usually with a slump of a vein (19) . Toxytrypana. 

Ovipositor not remarkably elongated and curved. . . 2 

2. Front on each side with a bristle having a terminal, leaflike ap- 

pendage Ceratitis. 

Front without such bristles. ....... 3 

3. Wings with colored markings not reticulate. .... 4 
Wings hyaline or with the markings reticulate or spotted. . 19 

4. Scutellum with six bristles (9). . . . Hexachaeta 
Scutellum not with six bristles. ...... 5 

5. Fourth longitudinal vein conspicuously curved forward at its tip 

(11.2O) Anastrepha. 

Fourth longitudinal vein not conspicuoiisly curved forward at its 
extremity. .......... 6 

6. Distal portion of the wings with two hyaline indentations, sepa- 

rated by a curved or arched brown proj ection from the brown 
oblique cross-band or spot before it, the anterior indentation 
more slender, the posterior one (in the second posterior cell, 
crossing or not the fourth vein) more triangular in shape. 7 

Wings with three such indentations. . . . Polionota. 

Wings not so marked. . . . . . . . II 


Figs. 112, 113. Trypetidav 1, Icterica; 2, Carj>}ifrirha;3, Eit(ir?sta; 4, Eu- 
treta: 5, Urellia: (3, Tephritis; 7, Oedaspis: 8, Xeoaspilota; 9, Hexarh*ta; 10, 
Straiissia; 11, Anastrepha; 12, Oedicarena; 15, Polymorphomyia; 1(3, Plagioto- 
ma; 17, Xenochceta; 18, Eurosta; 19, Toxotrypana (Snow); 20, Anastrepha, 
head; 21, Eunrcsta; 22, Eurosta; 23, Urellia: 24, Ensina: 26, Aciura; 27, 
Eutreta, (27) 


2 86 NORTH AMERICAN DIPTERA. 

7. Body elongate; abdomen narrower than the thorax. 

Body short; abdomen as broad as the thorax. ... 9 

8. The hyaline triangle at tip of first vein does not cross the third 

vein (1O) Straussia. 

The hyaline triangle at tip of first vein crosses the third vein. 

Molynoccelia. 

9. The horizontal diameter of the eyes remarkably short. Stenopa. 
Horizontal diameter of eyes not shorter than usual. . . 10 

10. Antepenultimate section of fourth vein straight. . Acidia. 
Antepenultimate section of fourth vein curved. Epochroa. 

11. Coloring of the body general light, never black. . . 12 
Coloring of the body black. . . . . . . . 16 

12. Wings near the middle with two cross-bands, converging toward 

the posterior margin. ...... 13 

Wings not with such cross-bands. ..... 14 

13. The third longitudinal vein is gently curved backward toward the 

tip; head not swollen Spilographa 

Third longitudinal vein straight to the extremity; head distinctly 
swollen (12). Oedicarena. 

14. Wings with four very oblique cross-bands. . . . . 15 
Cross-bands nearly transverse, or dissolved into spots; cross-veins 

but little oblique Trypeta. 

15. Scutellum tumid, bituberculate Peronyma. 

Scutellum of the usual structure, not swollen, though convex (16). 

Plagiotoma. 

16. Cross-veins conspicuously approximated. . . . ; 17 
Cross-veins not approximated. ..... 18 

17. Wings with hyaline indentation and a subapical, arcuate hyaline 

cross-vein; scutellum black (15). . Polymorphomyia. 
Wings with three brown bands or projections, connected anterior- 
ly, the distal one following the costa, the middle one beyond 
the middle of the wing, the proximal one toward the base (7) . 

Oedaspis. 

18. Scutellum with four bristles, yellow; wings with black cross-bands. 

Rhagoletis. 

Scutellum with two bristles, black; wings with hyaline indenta- 
tions along the margin (26) . .... Aciura. 


TRYPETID^E. 287 

19. Fifth vein strongly bristly; scutellum with six bristles. 

Blepharoneura. 
Fifth vein not bristly, scutellum with four or two bristles. 20 

20. Wings banded on the apex. ....... 21 

Wings not banded on the apex ...... 22 

21. Middle portion of wings finely reticulated. . . Acrotaenia. 
Middle portion of wings not finely reticulated. Baryphlegrna. 

22. Face spotted. .......... 23 

Face not spotted. ......... 24 

23. Wings very much dilated; pattern of picture not radiating (4, 27) . 

Eutreta. 

Wings not dilated; with radiating markings along the margin (2) . 

Carphotricha. 

24. Front very broad. ......... 25 

Front not very broad. ........ 27 

25. Third antennal joint elongate, with a sharp anterior angle; ovipos- 

itor flattened. ....... Acidogona. 

Third antennal joint short. ....... 26 

26. Wings with numerous small spots and larger ones along the distal 

margin; ovipositor conical (18,22). . . Eurosta. 

Wings with large, irregular brown spots and hyaline spaces (17) . 

Xenochseta. 

27. Wings without markings, or, on the apical half only with a retic- 

ulation dissolved into cross-bands (8) . . Neoaspilota. 

Flies not having the above characters. .... 28 

28. Wings of an evenly broad shape and with an unusually blunt dis- 

tal extremity (1) Icterica. 

Wings of the usual shape, or dilated. ..... 29 

29. Isabella very much prolonged (24) ..... Ensina. 
Isabella not or but little elongated. ..... 30 

30. Wing-markings radiating. . . . . . . . 31 

Wing-markings not radiating (6) .... Tephritis. 

31. The whole, or nearly the whole surface of the wings with an uni- 

colorous recticulation (3, 21). . . . . Euaresta. 

A star-shaped picture at the distal extremity of the wings, the re. 

remaining surface immaculate, or with a very few spots, or 

at the most with an obsolete reticulation (5, 23) . Urellia. 


XL. FAMILY SAPROMYZID^. 

Small species, seldom more than seven millimeters in 
length. Head as broad or a little broader than the tho- 
rax; front with one or two bristles on each side anteriorly 
to those of the vertex; post vertical bristles convergent. 
Antennae usually porrect, the third joint more or less 
elongated. Face without vibrissse on the oral mar- 
gin. Abdomen short ovate. Legs never elongate. Auxil- 
iary vein of wings distinct; cross-veins never approxi- 
mated; basal cells never obsolete. 

P I include in this family the Sapromyzidae and Lonchae- 
idse of Loew, Becker and other writers, since I believe 
that the relationship between such genera as Palloptcra 
and Sapromyza is evident, though I appreciate the differ- 
ences, and am not very insistent upon their union. The 
wings of both the Lonchaeinae and Sapromyzinae are often 
pictured. Czerney would include the Ochthiphilinae 
( Agromyzidae) in this family. 

The larvae of Sapromyza live in decaying vegetable 
matter; they are slender, with two distinct mouth-hook- 
lets; the entire body, except the anterior segments rough- 
ened by very small bristles. The segments are distinctly 
constricted, the penultimate segment with four conical 
processes in a transverse row, the terminal segment with 
two three-jointed processes, between which is the cylin- 
drical stigmatic tube. In Lonchcsa there are no conical 
processes on the penultimate segment, and the stigmatic 
tubes or processes are small and wart-like. 

TABLE OF GENERA. 

i. Tibiae without preapical bristle; front with a single orbital bristle; 

ovipositor horny and flattened (Lonch&intz}. ... 2 

Tibiae with a distinct preapical bristle; two fronto-orbital bristles; 

ovipositor not horny, ending tnbe-like (Sapromyzince) . 3 

288 


SAPROMYZIM;. 


289 


Fig. 114. Sapromyzidae. i, Lonchcea, wing; 2, Lonchcza, head; 3, 
Lonchtea, abdomen of female; 4, Sapromyza^ tibia and tarsus; 5, Sap- 
romyza, wing; 6, Physogenua (gen. nov.?) head; 7, Physogenua, 
head; 8, Lauxania wing; 9, Lauxania, head; 10, Pachycerma, head 
(Becker); n, Pachycerina verticalis, head; 12, Griphoneura, wing. 


290 


NORTH AMERICAN DIPTERA. 


2. Metallic black species; front rather narrow (1, 2, 3). Lonchsea. 
Yellow or yellowish species; front broad (p. So, 15) . Palloptera. 

3. Arista with short and dense plumosity; anterior fronto-orbital bris- 

tles proclinate (1O, 11) . .... Pachycerina. 

Arista bare, pubescent or loosely plumose; anterior fronto-orbital 

bristles reclinate. ........ 4 

4. Face broad, in profile strongly convex below (6, 7) . Physogenua 
Face receding, flattened or gently arched. ... 5 

5. First posterior cell much narrowed in the margin (12). 

Griphoneura. 
First posterior cell not or but slightly narrowed in the margin. 6 

6. Shining black species; third joint of antennae more elongate (8,9). 

Lauxania. 

More or less yellow or pollinose species; third joint of antennae less 
elongate (4, 5). . . . . . . . Sapromyza.* 

* From the description and figures I can discover no differences, 
save the imperfect anal cell, an unimportant character, to distinguish 
C/Hztocoslia from those species of Saproniyza having pictured wings. 


a 


Sapromyza, species; enlarged. 


XLI. FAMILY AGROMYZID^B. 

Front broad, with or without bristles. Antennae short, 
the third joint usually rounded, sometimes a little elon- 
gate or subquadrate; oral vibrissae usually present. 
Arista bare or pubescent, never distinctly plumose; rare- 
ly wanting. Genitalia rarely prominent. Wings broad; 
auxiliary vein vestigial or indistinct, never clearly sep- 
arated, save sometimes in its proximal part, from the 
first vein. Second basal and anal cells always small, 
oftentimes indistinct, or the second basal united with the 
discal ; cross-veins often much approximated, never very 
remote from each other. 

This family of small or minute flies, as here defined, 
includes four or five groups which various authors have 
either given independent rank or united with other 
groups. Czerny would unite the Ochthiphilinae with 
the Sapromyzidae, in which view I do not concur. The 
limits of the Agromyzinse and Milichinse, if there be any, 
will only be determined for our American genera by a 
more exhaustive stud}' than I can give to them; several 
of the genera I do not know: Eusiphona^ Hemeromyia, 
Arctobiclla, Patodinia. Czerny and Hendel make different 
combinations than do most other authors. The Agro- 
myzinse, according to these authors, have divergent post- 
vertical bristles, the Milichinse and Ochthiphilinae con- 
vergent. 

From the Drosophilidae the members of this family 
will be distinguished easily (in the American forms) by 
the nonplumose or nonpectinate arista. Nearly all the 
genera are at once distinguished from the Oscinidae and 
Ephydridae by the distinct, though small, posterior basal 
cells; but this character is sometimes difficult to detect 

291 


NORTH AMERICAN DIPTERA. 


Fig. 115- 


AGROMYZID^. 


293 


Figs. 115, 116. Agromyzidse. I, Anlacigaster, n. sp. (West Indies) , 
wing; 2, Anlacigaster, same species, head; 3, Phyllomyza magnipal- 
pis, head (); 4, Platophrymyia nigra, wing; 5, Platophrymyia, 
id. head; 6. Agromyzaxanthophora, wing; 7, Agromyza (gen. nov.?) 
head (); 8, Agromyza jucunda, head; 9, Ceratomyza dorsalis, 
wing; 10, Ceratomyza, id. head; n, Ophthalmomyialacteipennis, wing; 
12, Ophthahnoniyia, id. head (^); 13, Rhicnoessa cinerea, head ( J ) ; 
14, DesmoDietopa, sp. head; 15, Traginops irrorata, head(Coquillett); 
16, Phytomyza, sp. Phytotnyzinae; 17, Ochthiphila polystigina, Och- 
thiphilinae; 18, Paraniyia, sp. (Georgia), Pln-tomyzinae (?); 19, I\fili- 
chia leucogaster, Milichinse; 20, Agromyza, sp., Agromyzinas. 


294 


NORTH AMERICAN DIPTERA. 


in such small insects, and will usually require the use 
of a compound microscope; indeed such a microscope, 
with a one inch or half inch objective, is advised for the 
study of most of the species of the family. The absence 
or presence of the basal cells is not an important charac- 
ter in these and allied flies, and may not even have spe- 
cific value. Aulacigaster has been located in various 
families, but it seems to find its most natural place here. 
From the Geomyzidae the distinction of some of the gen- 
era is very difficult, if not impossible at present. One 
would better consult that family in case of doubt. 

The larvae of Phytomyza, and probably also of Par- 
amyia, are leaf miners; those of Ochthiphila have been 
found in the galls of Triticum repens. The larvae of Agro- 
myza are elliptical in shape, the hind stigmata situated 
upon small rounded plates on the under side of the last 
segment; the abdomen is provided with false legs, with- 
out bristles. The larvae of Leucopis are cylindrical, 
thicker posteriorly; the skin roughened with short hairs; 
hind stigmata elongate, tube-like and widely separated. 
The larvae creep leech-like, or like geometrid larvae. 


TABLE OF GENERA. 

1. Posterior cross-vein absent (Phytomyzinae). .... 2 
Posterior cross-vein present. ....... 3 

2. Proboscis elongate, folding; palpi long and thickened (18). 

Paramyia. 
Proboscis and palpi not elongated (16) . . . Phytomyza. 

3 . First posterior cell narrowed in the margin; proboscis long and 

geniculate.* Eusiphona. 

First posterior cell not or but slightly narrowed in the margin. 4 

4. Posterior cross-vein situated before the middle of the wing, the two 
cross-veins approximated. ....... 5 

The cross-veins not approximated. . . . . . .12 

* I do not know this genus, originally described as a tachinid; it 
must have a curious resemblance to Stylogaster (Conopidae) . 


AGROMYZIM 


295 


5. Posterior cross-vein opposite or before the anterior cross-vein, that 

is the second basal and distal cells together are but little longer 

or shorter than the first basal cell. . . Napomyza. 

Posterior cross-vein at least its own length beyond the anterior 

cross-vein. .......... 6 

6. The third antennal joint terminates in a spiny point (9, 1O) . 

Ceratomyza. 
Third antennal joint not terminating in a spiny point. . 7 

7. Third antennal joint rounded, of moderate size. . . 8 
Third antennal joint very large, subquadrate (3). Phyllomyza. 

8. Arista wholly wanting; second basal and discal cells confluent. 

Cryptocheetum. 
Arista present. ....... 9 

9. Proboscis long and geniculate. ..... 10 

Proboscis short and not geniculate. . . . . .11 

10. Front long and plane, or concave, longitudinally (4, 5). 

Platophrymyia.f 
Front shorter and convex (14). . . . Desmometopa. 

11. Vibrissse distinct!}" above oral margin; face strongly convex. 

Hemeromyia. 
Yibrissae not distinctly above the oral margin (6, 7, 8, 2O). 

Agromyza. 
No distinct vibrissae (see Ephydridse, (25,36). . Pelomyia. 

12. Second basal cell united with the discal cell; first basal cell but 

little longer than the anal (1,2). . . Aulacigaster. 
Discal cell separated from the second basal. . . . -13 

13. Oral vibrissae present (Milichinse). ..... 14 

Oral vibrissae wanting; postvertical bristles convergent; auxiliary 

vein usually distinct from first longitudinal through a consider- 
able part of its course (Ochthiphilinse) . .... 21 

14. Costa with a distinct incision before the tip of the first vein. 15 
Costa not with such incision. ...... 16 

15. First posterior cell narrowed in the margin; posterior orbits with 

a distinct incision (1112). . . . Ophthalmomyia. 

First posterior cell not narrowed in the margin; posterior orbits 

not incised (19) Milichia. 

t I am not sure of the distinction of this genus from Desmometopa. 


296 NORTH AMERICAN DIPTERA. 

16. Front projecting forward anteriorly in a high angular eminence 

(15) Traginops. 

Front not so projecting. ....... 17 

17. Vibrissae not well differentiated from the adjacent hairs; rather 

thickly haired species; eyes densely pubescent. Arctobiella. 
Vibrissse distinctly differentiated. . . . .18 

18. Mesonotum with bristles on the sides only. . . Cacoxenus. 
Mesonotum with bristles in the middle also. ... 19 

19. Only two pairs of fronto-orbital bristles. . . Parodima. 
Three or four pairs of fronto-orbitals. ..... 20 

20. In addition to the usual fronto-orbital bristles there is an inner 

row of frontal bristles or bristly hairs (13). . Rhicnoessa. 
No additional row of bristles. ..... Odinia. 

21. Head triangular in outline, the front strongly projecting, the face 

much retreating, almost horizontal. . . Acrometopia. 
Head not of such form. . . . . . * . . .22 

22. No orbital or ocellar bristles. .... Leucopis 
Orbital bristles present. ........ 23 

23. Front with a transverse groove near the middle. Pseudodinia. 
Front not with transverse groove (17). . Ochthiphila. 


FAMILY GEOMYZID^. 

Head rounded, usually with vibrissae at oral margin; 
front broad, with one, two or three pairs of fronto-orbital 
bristles; postvertical bristles convergent. Antennae 
short, the third joint rounded or a little elongated, with a 
bare, pubescent, pectinate or plumose arista. Wings 
comparatively long; auxiliary vein always coalescent 
distally with the first vein; posterior basal and the anal 
cells small but distinct. 


Fig. 117. Geomyzidae. i, Sinophthahnns pictns, wing; 2, Sinoph- 

thalnins pictus, head; 3, Spilochroa ornata, wing; 4, Spilochroa orna- 

ta, head; 5, Anthomyza tennis, wing; 6, Anthomyza tennis, front; 7, 

Anthomyza tenuis, front leg; 8, Chiromyiaflava, wing; 9, Chironiyia 

JJava, head. 

This small group of small flies, as here limited, in- 
cludes the Geomyzidae and Opomyzidae of L,oew, and the 
Anthomyzidae of Czerny. The limits of the family are 

(28) 297 


298 NORTH AMERICAN DIPTERA. 

not at all sharp, and no two writers agree as to what they 
are; indeed there seem to be none. Curtonotum is not in- 
cluded here, but will be found among the Drosophilidae. 
Tauromyia, which v. d. Wulp thought might belong to 
this group, is most assuredly not a Geomyzid. 

The larvae of those few species of which the habits are 
known, live in the stems of plants. 

TABLE OF GENERA. 

1. Oral vibrissae distinctly differentiated. ..... 2 

Oral vibrissae absent or indistinctly differentiated from adjacent 

1 1 1 1 1 I*S . -*....O 

2. Mesonotum bristly in the middle in front. .... 3 
Mesonotum bristly in the middle on the posterior part onh r . 5 

3. Arista pectinate above; one orbital bristle. . . Balioptera. 
Arista not pectinate; two fronto-orbital bristles. ... 4 

4. Cheeks as broad as the vertical diameter of the eyes; wings un- 

marked. ........ Zagonia. 

Cheeks narrow; wings variegated (Heterochroa (Peratochcctiis] or- 
nata Johnson) (3,4). . . . Spilochroa Will. 

5. Under side of front femora with bristles or bristle-like spines. 6 
Under side of front femora not with bristles or spines. Diastata. 

6. Second longitudinal vein strongly curved forward, flexuous (p. So, 

14). . . . Ischnomyia, 

Second longitudinal vein not flexuous. ..... 7 

7. Face with a nose-like carina above; no postvertical bristles; front 

with one proclinate bristle on each side (1, 2) . 

Sinophthalmus. 
Face not carinate; two reclinate bristles on each side (5, 6, 7). 

Anthomyza. 

8. Occiput flattened; wings spotted. ...... 9 

Occiput convex; wings not spotted (8, 9, Scyphella] . 

Chiromyia Bezzi. 

9. Arista long plumose. Scutops. 

Arista not plumose. ....... Opomyza. 


XLIII. FAMILY 

Face nearl} r vertical in profile, with oral vibrissae, 
which are sometimes weak. Front with long bristles, 
not reaching to the anterior part; postvertical bristles 
convergent; foremost orbital bristle usually proclinate. 
Third joint of the antennae oval or rounded, the first two 
short; arista almost always plumose or strongly pectin- 
ated, though sometimes the rays may be much reduced 
in number or, rarely, entirely wanting. Abdomen usu- 
ally short; more elongate in Curtonotum. Auxiliar} T vein 
incomplete or indistinct: an incision in the costa before 
the termination of the first vein ; first longitudinal vein 
short, not reaching a third of the length of the wing; 
posterior basal cell usually united with the discal cell, 
though sometimes complete; anal cell usually present, 
but sometimes indistinct or entirely wanting: posterior 
cross- vein absent in Asteia. 

The species of this family are almost always small, sel- 
dom exceeding a length of five or six millimeters and 
usually from one to three; of rather a plump appearance, 
giving a feeling of coldness to the fingers when grasped. 
The bristles of the front are usually conspicuous, but the 
body is without hair. The flies are often caught with 
the beat-net, and some species are especially abundant 
about decomposing or fermenting fruit, cider refuse, wine 
vats, vinegar, etc.; and some are annoying to the house- 
wife about preserves ; even the breath of one who has 
recently drank wine seems to attract them. 

The great majority of the species the student meets 
are easily enough located by the absence of the auxiliary 
vein and second posterior cell together with the plumos- 

ity of the arista and distinct oral vibrissae. Unfortunate- 

299 


300 


NORTH AMERICAN DIPTKRA. 


Fig'. 118. Drosophilidae. T, Phortica, wing; 2, Phortica, head; 3, 
Stegana, wing; 4, Stegana, front leg of male; 5, Drosophila, wing; 6, 
Drosophild) wing; 7, Sigaloessa(?} ; wing; 8 Drosophila, front, show- 
ing bristles; 9, Leucophenga, wing; 10, Curtonotum, wing; n, Cur- 
) head. 


DROSOPHILID^. 


301 


ly there are not a few which, as at present understood, 
are not so easily distinguished from two or three other 
families, especially the Ephydridae and Oscinidse, those 
in which the second basal cell is usually incomplete; and 
the student would best consult those families when in 
doubt. Aulacig aster has been refused admission here and 
referred to the Ephydridae by some ; others would locate 
it here or among the Agromyzidse. Curtonotum has also 
somewhat doubtful claims for admission here, since the 
auxiliary vein, in some species at least, is less rudimen- 
tary. Because of the characteristically proclinate fore- 
most orbital bristle and general structure of the head, 
especially, I believe that its claims are good for location 
with the true Drosophilidae; at least I am confident that 
it does not belong with the Geomyzidae, where it is often 
located. Asteia and Sigaloessa, or at least the former, 
were placed by Loew in a distinct family. True Sigaloes- 
SCE agree best in habitus with the Oscinidae; but there are 
other forms that must for the present at least be placed 
in the genus, which seem to be nearest to Drosophila. 
Stoiomicra, judging from the description, must also be 
an aberrant form. 

TABLE OF GENKRA. 

1. Discal ami second basal cells united. ..... 3 

Discal and second basal cells separated by a cross- vein. . . 2 

2. Second and third veins markedly convex anteriorly; first posterior 

cell narrowed in the wing margin; front tarsi of male dilated (in 
Some species at least) ; wings appearing as though broken 
down over the abdomen (3,4). . . . Stegana'. 

Second and third veins not markedly convex; wings not appearing 
as though broken down (p. 80, 12, and 1, 2) . Phortica.* 

' The species of Phortica figured in 1, 2 (from South America, a fe- 
male specimen) has the first posterior cell much narrowed in the mar- 
gin. Phortica scutellaris (West Indies) has the male front tarsi 
dilated, but the first posterior cell wide open. I do not know whether 
the dilated front tarsi is a generic character or not, or whether there 
are forms included in Phortica which should be separated generically. 


3 02 NORTH AMERICAN DIPTKRA. 

3. Second section of the costa much shorter than the third;* anal cell 

wanting. .......... 4 

Second section of the costti at least as long as the third. . 5 

4. Posterior cross- vein absent. ..... Asteia.t 

Posterior cross-vein present (7 and 7 Oscinidse). Sigaloessa.t 

5. Arista bare, except for a single ray near its base; two fronto-orbital 

bristles on each side. ..... Cladochseta. 

Arista plumose or with numerous pectinations. ... 6 

6. The costa reaches to the third vein or a little beyond. . . 7 
The costa reaches to the fourth vein or a little beyond. . . 8 

7. Costa with sparse but conspicuous bristles; thorax arched, bristly 

behind; scutellum with long bristles; abdoman elongate, droop- 
ing; larger flies (1O, 11) . . . . . Curtonotum. 
Costa not with bristly pectinations (9). . , Leucophenga.J 

8. Ultimate section of fourth vein seven or eight times longer than the 

penultimate; a single fronto-orbital bristle on each side; no alu- 
lae; first posterior cell narrowed in the margin. Stenomicra.? 
Ultimate section of fourth vein not more than four times the length 
of the penultimate; first posterior cell not appreciably narrowed 
in the margin (5, 6, 8) Drosophila. 

* If first basal cell but little longer than the anal, and the arista bare 
or pubescent, see Aulacigaster (Agromyzidse) . 

t I do not know Asteia, but the venation of the type species of the 
genus seems to be almost identical with that of Sigaloessa as figured 
with the Oscinidse (7), save that the posterior cross-vein is absent. 
The venation of Sigaloessa as there given is the more typical; that 
given in fig. 7 herewith is apparently that of Schiner (South America 
and West Indies) . In which family the genera should be placed is at 
present a mere matter of opinion. 

J Including such species as Drosophila frontalis and perhaps others 
described as Drosophila. 

$ This genus seems to be peculiar in its approximated cross-veins, 
and single fronto-orbital bristle. I do not know it. 


XLIV. FAMILY 

Face more or less, often remarkably convex. Antennae 
short; first joint small; antennal arista bare or pubescent, 
or pectinated upon the upper side. Oral cavity rounded, 
usually large; clypeus distinct, in some cases retracted 
within the oral cavity and not visible, in others very 
prominent; without distinct vibrissal bristle. Abdomen 
of variable form, composed of six segments in the males, 
seven in the females, never elongated; sexual organs 
usually retracted. Wings rarely aborted; auxiliary vein 
coalescent for the most part with the first longitudinal 
and distinct only at its proximal end; distinct through- 
out in Canace ; costa broken before tip of first vein and 
more or less distinctly a little distance beyond the hum- 
eral cross-vein; second basal cell confluent with the dis- 
cal cell, the anterior basal cross-vein entirely absent or 
only dimly visible: distinctly present in Canace only; 
anal cell imperfect and small; distinct in Canace and Pe- 
lomyia. Middle tibiae with spur; no preapical bristle. 
Body usually bare or nearly so of hairs. 

The flies of this family are never large, often small or 
even minute. The greater number of species are inhab- 
itants of wet places, about marshy ground, meadows, 
etc., and are usually caught in the beating net. They 
are always thinly pilose or bare species, and never with 
bright colors. The extraordinarily large mouth of some 
species is very characteristic, but in others this character 
is not so apparent; and there is sometimes difficulty in 
separating the genera from those of the Drosophilidae. 

The name of 'brine flies' or 'salt water flies' has some- 
times been given to the family, but not very happily, 
since the greater number live about fresh water. Brachy- 

303 


304 


NORTH AMERICAN DIPTERA. 


Fig. 119. Epbydridae. Psilopa nigra, head; 2, Psilopa aciculata, 
wing. 3, Allotr ichoma abdominale, head ; 4, Pa rep hydra facial is, 
head; 5, Ephydra pygmcca, head; 6, Notiphila, sp., wing; 7, Hydrina 
nitida, head; 8, Hydrina nitida, wing; 9, Hydrellia parva, wing; 10, 
Ochtheroidea atra, wing; u, Athyroglossa nitida, head. 12, Disco- 
myza dubia, head. 

deutera argentata has a wide distribution over all of North 
and South America, the West Indies, Hawaiian Islands, 
etc. The flies of this species have the under surface of 
the body of a silvery, non-wetable character, enabling 
the insects to run about on the surface of the water. The 
larvae doubtless live in the water, though not necessarily 
in foul water as has been thought. 

The larvae of many forms are peculiar, resembling 


EP HYDRIDE. 


305 


somewhat the rat-tailed larvae of the Syrphidae. The 
mouth, however, always has booklets, and the 'tail' is 


Fig. 120. Ephydridse. 18, Lt/toyaster, sp. (Illinois), wing; 14, Lytoyaster, 
abdomen; 15, Lytogaster, head; 16, Oc/tthcra, sp. wing; 17, Ochthera, sp. front 
leg; 18, Ochtheroidea a'tra, male, front leg; 19, Brachi/dentera aryentata, wing; 
20, Rrachydeiitera argentata, head; 21, Discocerina, sp. head; 22, Discocerina, 
sp. bristles of front; 23, Gastrops, sp. head; 24, Part/dra sp. wing; 25, Pelo~ 
mj/ia occit/pntdlix, l>ristles of tlioracic dorsum; 26, 27, Liporfurta, head (Co- 
(jiiillett). 


306 


NORTH AMERICAN DIPTKRA. 


forked at the end. The larvae of species of Notiphila have 
been observed in the stems of water plants; those of Hy- 
drellia in the sap of trees, in the parenchyma of the leaves 
of Lemna, on A/isma, etc., those of Pelina, Ephydra, 
Parydra, etc., in water, often salt or alkaline. 

The bristly spine of the second anteunal joint is some- 
times not easily discernible. I have included in both 
sections some of the genera about which doubt may arise. 


Fig. 121. Ephydridae. 28, Beckerieila bispinosa, wing; 29, Parydra bituber- 
culata, head: 30, Mosillus, sp. wing; 31, Mosillus, sp. liead; 32, Scatella stag- 
rial is, wing; 33, llythea ftavipes, wing; 34, Ilyihea flavipes, head; 35, Pelomyia 
occidentalis, head; 3d, Paralimna, sp. middle tibia; 37, Genus ? (Illinois). 

TABLE OF GENERA. 

1. Second basal and anal cells complete ; auxiliary vein distinct 

throughout; third antennal joint spherical. . . Canace. 

Second basal cell confluent with discal cell; aiixiliary vein coales- 

cent distally with first vein. ...... 2 

2. Antennae small, inserted remotely in cavities, the arista atrophied; 

eyes pubescent; bristleless flies (26, 27). . Lipochseta. 
Not such flies. 2 

3. Second joint of antennas with a spinous bristle at upper distal cor- 

ner. ........... 4 

Second antennal joint without such bristle. 16 


307 

4. The costal vein reaches to the tip of the third longitudinal vein. 5 
The costal vein reaches to the tip of the fourth vein. . . 6 

5. Tip of male abdomen with two elongated, upwardly curved bris- 

tles; two fronto-orbital bristles present. . . Dichseta. 

Tip of male abdomen without such bristles; a single orbito-frontal 

bristle present (6). ....... Notiphila. 

6. Abdomen broad, nearly circular in outline ; palpi broad ; arista 

pectinate (12). ....... Discomyza. 

Not such flies. .......... 7 

7. Face on upper part flat or gently convex, not carinate. . 8 
Face distinctly carinate above. .... .11 

8. Third antennal joint longer than broad (1, 2). Psilopa. 
Third antennal joint rounded, not longer than broad. . . 9 

9. Front with two pairs of bristles in the middle below the ocelli, di- 

rected forward. . ..... Paratissa. 

Front not with such bristles. ....... 10 

10. Mouth of large size; arista pectinate. . . . Ptilomyia. 
Mouth small; arista bare; four pairs of strongly developed dorso- 

central bristles present; anal cell small but distinguishable (25, 
35) Pelomyia.* 

11. Oral opening large; three or four bristles on either side of the face 

below. . . . . . . . . . . .12 

Oral opening not large. ........ 13 

12. Clypeus prominent ; ocellar bristles inserted above lowermost 

ocellus (4). . . . . . . . Parephydra. 

Clypeus small or hidden (33, 34) . .... Ilythea. 

13. Clypeus prominent; face gibbous below, . . . .15 
Clypeus projecting but little from oral cavity. . . .14 

14. Eyes long; cheeks narrow; face feebly or not at all gibbous (21, 

22). Discocerin a - 

Eyes round; cheeks broad; face gibbous; scutellum with four bris- 
tles (3) Allotrichoma. 

15. Arista bare ; third and fourth veins gently convergent distally; 

head without strong bristles (3O, 31) . . . Mosillus. 
Arista pectinate; third and fourth veins not at all convergent (11). 

Athyroglossa. 

f I suspect that this genus belongs with the Agromyzidae. I have 
seen specimens from Massachusetts, scarcely distinguishable 
specifically, in which the second basal cell is complete. 


NORTH AMERICAN DIPTKRA. 

16. Middle tibiae with several long bristles on the outer side (36). 

Paralimna. 
Middle tibiae not with long bristles exteriorly. . . .17 

17. Face with a large protuberant gibbosity, below which the profile is 

nearly vertical; abdomen broad; legs hairy (23). Gastrops. 
Face at most only evenly convex; legs not noticeably hairy. 18 

18. Oral opening small. ........ 19 

Oral opening large. ........ 27 

19. Front femora thickened. ....... 20 

Front femora not unusually thickened. . . . . 21 

20. Front femora much thickened, their tibiae with a terminal spine; 

third and fourth veins convergent distally (16, 17). Ochthera- 

Front femora moderately thickened, with spines on the under side 

distally, in the male at least; first posterior cell not narrowed; 

smaller species (18) . . , . . . Ochtheroidea. 

21. Second segment of the abdomen as long as the three following 

together; eyes densely pubescent. . . . Nostima. 
Second segment of abdomen shorter than the two following to- 
gether. ........... 22 

22. Fourth abdominal segment unusually long and broad; arista bare; 

sixth vein unusually convex before the cross-vein; third anten- 
nal segment obtusely angulated above; eyes bare (13, 14, 15) . 

Lytogaster Becker.* 
Fourth abdominal segment not unusually long and broad. 23 

23. Kyes thickly but short pubescent (9). . . . Hydrellia. 
Eyes sparsely pubescent or bare. ...... 24 

24. Mesonotutn with four strongly developed dorsocentral bristles on 

each side; arista bare; oral opening small; face without strong 
bristles (25,35). . .... Pelomyia. 

Mesonotum with three or four dorsocentral bristles. . . 25 

25. Sides of the face wholly without bristles. . . Hyadina. 
Sides of the face with bristles. ...... 26 

26. Eyes wholly bare; clypeus projecting. .... Pelina. 
Eyes sparsely pubescent; clypeus hidden (Philygra] (7, 8). 

Hydrina. 

* I refer to this genus two undetermined species, one from Illinois, 
the other from Brazil. The face, however, is not or but feebly carin- 
ated above; the fifth segment is also large, the abdomen very convex 
distally. 


EPHYDRID.^. 


309 


27. Clypeus prominent. ........ 28 

Clypeus hidden. ...... . . 29 

28. The costal vein reaches to the third longitudinal vein (19, 2O) . 

Brachydeutera. 
The costal vein reaches to the tip of the fourth vein (24, 29) . 

Parydra. 


29. Claws almost straight; pulvilli indistinct (5). 
Claws curved; pulvilli distinct. 

30. Oral border quite bare (33,34). 

Oral border bristly. ..... 

31. Arista pubescent (32). .... 
Arista pectinated. ...... 


Ephydra. 
30 

Ilythea. 

3i 

. Scatella. 
Ceenia. 


Ochthera huinilis, enlarged. 


29 


XLV. FAMILY OSCINID^E. 

Small, bare species. Head usually hemispherical; face 
usually nearly vertical in profile; oral border rarely with 
vibrissae; front broad, flattened, sometimes with bristles. 
Antennae usually short and the third joint rounded. Gen- 
italia hidden. Wings moderately or very short; auxil- 
iary vein vestigial; posterior basal cell united with discal 
cell; posterior cross-vein sometimes wanting; anal cell 
vestigial or wholly absent. Legs short; femora rarely 
thickened; tibiae without preapical bristle. 

This family of flies is always sure to be represented by 
numerous specimens and species in any collection of dip- 
tera. The flies are very common, and are collected in 
large numbers by the sweep-net from rank growing grass 
and over meadow-lands. Most characteristic of the fan.- 
ily is the absence of auxiliary vein and the posterior 
basal and. anal cells, in these respects, however, agree- 
ing with the Ephydridae, from which they will usually 
be distinguished by their lighter colors the Ephydrids 
are almost invariably black, the smaller mouth, the 
usually bare arista, the occasional presence of oral vibris- 
sae, etc. 

The larvae of several species of Oscinis have been bred 
from wheat, oats, rye and grass stems, and Phragmites; 
the larvae of Siphonella from Cirsium, etc. The larvae 
are thick, cylindrical, with stout mouth-booklets; the 
abdomen has fleshy protuberances for locomotion ; the 
antennae are two-jointed. 

Aldrich has recently expressed the suspicion that the 
genus Hippelates is not well founded, and I am inclined 
to agree with him. While the presence of a booklet at 
the tip of the hind tibiae would seem decisive, yet its 

310 


OSCINID^E. 3II 

presence in the genus Ceratobarys, and the structure of 
the proboscis in Hippelates would seem to render proba- 
ble that a thorough revision of the genera of this family 
may eliminate some now generally accepted. 


Fig. 122. Oscinidae. i, Hippelates, sp.; 2, Elachiptera^ sp.; 3, 
Gaurax anchora, head; 4, Eurina e.vilis, head; 5, Meromyza arneri- 

cana, wing; 6, Meromyza americana, hind leg; 7, Sigaloessa, n. sp. 
wing (Illinois). 


3 I2 


NORTH AMERICAN DIPTKRA. 


10 


Fig. 123. Oscinidse. 8, Siphonella, n. sp. venation; 9, Siphonel/a, 
head; 10, Ectecephala (?) species (Brazil), head; u, Ectecephala, wing; 
12, Eurina, sp. antenna. 

TABLE OF GENERA. 

1. The costal vein reaches to the tip of the third longitudinal vein 

or a little beyond. ... 10 

The costal vein reaches to the tip of the fourth longitudinal vein. 2 

2. Second longitudinal vein very short, terminating in the costa near 

or but little beyond the insertion of the first vein. . . 3 

The second section of the costa is at least as long as the third sec- 


tion. 


Asteia. 
Sigaloessa. 


3. Posterior cross-vein absent. .... 
Posterior cross-vein present (7). . 

4. Antennal bristle thickened, style-like. .... 5 
Antennal arista as usual, slender, bare, pubescent or rarely plu- 
mose. ........... 6 

5. Hind tibiae with a curved spur at the tip on inner side. 

Ceratobarys. 
Hind tibiae without such spur (2). . . Elachiptera. 

6. Hind tibiae with a curved spur at tip on inner side; proboscis often 

elongated and geniculate (1) Hippelates. 

Hind tibiae without such spur. ....... 7 


OSCINIDJE. 313 

7. Facs concave in profile, the oral margin produced. . . 8 
Face receding in profile, the oral margin not produced. . 9 

8. Oral vibrissae wanting; proboscis often elongated and folding (8, 

9) Siphonella. 

Oral margin with vibrissae; proboscis fleshy, not folding ; front 
with bristles (see fig. 37, Ephydridae. Genus new?) 

9. Third antennal joint round or oval, with a bare or pubescent dor- 

sal arista.* ........ Oscinis. 

Third antennal joint more reniform, with a subterminal short- 
plumose arista; eyes pubescent (3) .... Gaurax. 

10. No posterior cross-vein; first three longitudinal veins curved 

forward Elliponeura. 

Posterior cross-vein present. . . . . . . n 

11. Head produced conically in front. ..... 12 

Head not produced conically in front. ..... 13 

12. Third antennal joint much longer than wide; eyes large; front 

excavated. ....... Ectecephala. 

Third antennal joint but little longer than wide, oval or reniform; 
eyes not large; front not narrowed nor excavated (4, 12). 

Eurina. 

13. Hind femora much thickened (5,6). . . Meromyza. 
Hind femora not thickened. ..... Chlorops. 

* If shining black species, the face rather convex and roughened, 
the arista bare, compare Mosillus, Ephydridae. 


XLVI. FAMILY DIOPSID^). 


Fig. 124. Sphyracephala brevicornis, enlarged. 

Small, bare species. Head prolonged into a lateral pro- 
cess on each side bearing the eye; front bristly on the 
upper part only; no vibrissae on the border of the mouth. 
Front femora thickened. Auxiliary vein much approx- 
imated to the first longitudinal vein; discal and second 
basal cells confluent. 

But a single species of this family, Sphyracephala brev- 
icornis Say, is known from North America, and it will 
be easily enough recognized by the singular eye-stalks. 
The habits, whether of the adults or larvae, are not 
known, nor are they known of any other member of the 
family, so far as I am aware. 


3*4 


XLVII. FAMILY BORBORID^). 

Rather small to very small, black, brown or obscurely 
yellowish flies, having a quick, short flight. Head hem- 
ispherical; vibrissae present ; front broad, usually bristly. 
Antennae short; third joint rounded or obtusely pointed 
with a dorsal or terminal, bare or pubescent arista. 
Wings rarely absent ; auxiliary vein wanting or indis- 
tinct, never clearly separated; second basal and anal 
cells often incomplete or absent. Legs moderate^ long 
and strong; hind metatarsi usually dilated and abbre- 
viated. 


Fig. 125. Borboridae. i. Sphcerocera, wing; 2, Limosina venali- 
cia, wing; 3, Limosina perparra, wing; 4, Limosina perparva, an- 
tenna; 5, Limosina lugubris, wing; 6, Borborus. sp. wing; 7, Bor- 
borus, sp. antenna; 8, Borborus, sp. hind tibia and tarsus. 


315 


316 NORTH AMERICAN DIPTERA. 

The flies of this family are almost invariably found 
about decomposing organic matter. Those belonging to 
Borborus and Sph&rocera are observed, often in clouds, 
about dung and refuse, where their larvae live. The 
small flies of the genus Limosina are seen in abundance 
in marshy places in company with the smaller ephydrids. 

The larvae of Borborus are cylindrical, with the skin 
roughened by erect, minute bristles; the antennae are 
two-jointed, the mouth-hooklets well developed; the pos- 
terior end has conical processes near the anus, and small- 
er tubercles about the spiracles; in Limosina the hind 
stigmata are tube-like. The larvae of Limosina live in 
fungi, algae, diseased potatoes, and perhaps water. 

TABLE OF GENERA. 

1. Wingless species, Aptilotus. 

Wings fully developed. ........ 2 

2. Fourth and fifth longitudinal veins incomplete or obsolescent be- 

yond the discal cell; second basal cell incomplete (2, 3, 4, 5). 

Limosina. 

Fourth vein at least, fully developed; second basal and the anal 
cells complete. ......... 3 

3. Scutellum with well-developed bristles; fifth vein incomplete be- 

yond discal cell; metatarsi shorter than second joint (6, 7, 8). 

Borborus. 
Scutellum without bristles; fifth vein complete (1). Sphserocera. 


XLVIII. FAMILY PHYCODROMID^E. 

Mesonotum, scutellum and abdomen flat. Front bristly; 
cheeks and face bristly, the vibrissae indistinctly differ- 
entiated. Legs stout, all the tibiae spurred and with a 
preapical bristle on the outer side ; metatarsi not abbre- 
viated; terminal joint of all the tarsi incrassate and with 
stout claws. Venation complete ; auxiliary vein distinct 
in its entire course; costa without bristles; basal cells 
not very small. 


Fig. 126. Phycodromidae. Ccelopa, wing, head, and front tibiae 

and tarsus of male. 

But two genera of this family are known from North 
America. Species of the genus Ccelopa are observed, 
often in abundance, among sea-weeds thrown up by 
the waves along the sea-shore. Recently Mr. Coquillett 
has added another genus, Omomyia, from California (Ca- 
nadian Entomologist, 1907, p. 76), differing from Ccelopa 
in having the scutellum nearly one-half as long as the 
mesonotum, distally subtruncated, bare, and with two 
pairs of lateral bristles. The habits of the type species 
(O. hirsuta} are not given. 

3V 


. FAMILY HETERONEURIB^. 

Head broad, subhemispherical. Face short, nearly 
vertical; vibrissae present. Front broad, bristly to or 
nearly to the root of the antennae. Ocellar bristles usu- 
ally present; postvertical bristles divergent. Antennae 
porrect; first two joints short, the third usually rounded; 
arista bare, pubescent or short plumose. Proboscis short; 
palpi rather broad. Body more or less elongate. Legs 
rather long and slender; tibiae with or without a preapi- 
cal bristle. Venation complete ; basal cells small; first 
longitudinal vein short, the auxiliary narrowly sepa- 
rated from it; sixth vein not reaching the wing margin. 

The members of this small family of rather small flies 
are to be found throughout the summer in shady places 
by the sides of brooks, or in the forests about the trunks 
of decaying trees; in damp meadowy places among the 
grass; on leaves, etc. 

Larvae of this family have been found in decaying wood, 
under bark of trees, etc. They are slender, cylindrical, 
slightly thickened posteriorly, white in color. The mouth 
booklets are very small, the body segments not distinctly 
separated; abdominal segments with a transverse swell- 
ing for locomotion. The larvae have the power of leap- 
ing as have those of Piophila. The act is performed by 
fixing the mouth booklets in the two chitinous, straight 
or curved booklets on the upper side of the last segment 
and then suddenly releasing them. The puparia are 
yellowish, ellipsoidal and with two horns on the last 
segment as in the larvae. 

Mr. Czerny has attempted recently to break up the 
genus Heteroneura, using for generic characters the bris- 
tles of the front chiefly. I gravely doubt whether all 

318 


HETERONEURIDJE. 


319 


his genera will be found valid eventually. Heteringomyia 
he diagnoses as differing from Heteroneura in the absence 
of cruciate bristles (a pair of small bristles toward the 
middle of the lower part of the front) and the absence of 
preapical bristle on the tibiae. H.flavipes, lunibalis and 
valida lack the cruciate bristles, but one of them, (H. 
lumbalis} has a distinct preapical bristle, so that this 
character is rendered invalid, or the cruciate bristle char- 


Fig. 127. Heteroneuridae. i, Heteroneura, wing; 2, Heteroneura, 
head from in front showing arrangement of bristles (Czerny); 3, 
Heteringomyia, head from in front showing arrangement of bristles 
(Czerny); 4, Chtztoclusia, head; 5, i'hcctoclusia, wing; 6, Hetero- 
ncura, head; 7, Clusia, head (Czerny). 


NORTH AMERICAN DIPTERA. 

acter; which I leave for Mr. Czerny to decide. His 
genus Hendelia he distinguishes from Heteroneura by the 
absence of the post-vertical bristles, and the more remote 
insertion of the antennae from each other. Mr. Coquillett 
has added another, based chiefly on the absence of both 
postvertical and cruciate bristles. Still another from 
South America (fig. 6) differs in the arrangement of 
these bristles. Possibly such a division of the species 
is natural, but I am yet to be convinced that it is. I 
omit the preapical bristle character in the table, since 
that, at least, seems worthless, as was observed long ago 
by L,oew. 

TABLE OF GENERA. 

1. Cross veins approximated, the penultimate section of the fourth 

vein not more than one fourth the length of the ultimate sec- 
tion. ........... 2 

Cross veins not approximated; the penultimate section of the fourth 
vein at least one-third the length of the ultimate section (7 and 

p. 80, 16.) Clusia. 


2. Postvertical, ocellar and cruciate bristles distinpt (Clusiodes Coq.) 

(1, 2) Heteroneura. 

Post-vertical and ocellar bristles present, the cruciate absent (3) . 

Heteringomyia. 

Postvertical and cruciate bristles absent, the ocellar obsolescent; 
distal end of first vein bristly (4, 5) . . . Chsetoclusia. 

For Peratoch&tus ornatus, see Geomyzidae (Spi/ochroa.} 


. FAMILY SCIOMYZID^E. 


Fig. 128. 


'l\'tanvccra utiibraruin , enlarged. 


Head short*, as broad or broader than the thorax; face 
more or less retreating ; mouth without v.brissae at its 
border, the margin angular. Abdomen composed of six 
segments, rather long and narrow. Wings longer than 
the abdomen; auxiliary vein present, distinctly separated 
from the first longitudinal vein ; posterior basal cell and 
the anal cell complete. Legs rather long; preapical 
tibial bristle present. 

* The genus Trigonometopus will be brought here by the family 
table. It has been variously referred to the Heteroneuridae, Sciomy- 
zidae, Ortalididse, Sapromyzidae by authors. It will be recognized by 
itsprojecting head and very retreating face. 

(30) 


321 


322 


NORTH AMERICAN DIPTERA. 


The members of this family are usually found in mead- 
ows, along the banks of small streams, etc., wherever it 
is moist. They are, for the most part, brown or brownish 
yellow in color, oftentimes with pictured wings. They 
are slow in their habits. The larvae are slender, cylin- 
drical, thin anteriorly; the last segment with six or eight 
conical, fleshy tubercles. They are aquatic. 


Fig. 129. Sciomyzidse. i, Sepedon, wing; 2, Sepedon, hind leg; 
3, Sepedon, head; 4, Tetanocera, wing; 5, Tetanocera, head; 6, Scio- 
itiyza, wing; 7, Sciomyza, head; 8, Thecomyia, head; 9, Trigorwme- 
topus, head. 


SCIOMYZID^. 


323 


TABLE OF GENERA. 

1. Second joint, at least, of antennae short. .... 2 
Antennae elongated. ......... 

2. Face excavated, the oral margin protuberant. .... 4 
Face retreating in profile, but little or not at all excavated; oral 

margin but little or not at all prominent. .... 3 

3. Head strongly projecting forward (9). . Trigonometopus. 
Head not at all projecting (7). .... Sciomyza. 

4. Cheeks broader than the long diameter of the eyes; oral border 

moderately protuberant; costa somewhat spinose. Actora.* 

Cheeks not broader than the long diameter of the eyes; oral margin 

very prominent; costa bare. ...... 5 

5. Clypeus prominent. ......... 6 

Clypeus not prominent. ........ 7 

6. Scutellum with four bristles on its border. . Neuroctena. 
Scutellum with six bristles (p. 80, 17, 18). . Heterocheila. 

7. Front tibiae with a preapical bristle. . . . Bischofia. 
Front tibiae without preapical bristle. . . . Dryomyza. 

8. Hind femora long; second antennal joint much elongated, longer 

than the third. ......... 9 

Hitid femora only moderately elongated and but little thickened; 
second antennal joint as long or a little shorter than the third 
(5) Tetanocera. 

9. Hind femora thickened; face not produced downward (1, 2, 3). 

Sepedon. 
Hind femora not thickened; face much produced downward (8). 

Thecomyia. 

* Of doubtful occurrence in North America. 


LI. FAMILY 


Fig. 130. Leria pnbescens, enlarged. After Washburn. 

Face nearly vertical, or retreating, with oral vibrissae; 
front bristly on the posterior half only; antennae short. 
Abdomen rather broad and long, composed of six seg- 
ments; male genitalia somewhat prominent. Wings com- 
paratively large; all the basal cells distinct; costa usu- 
ally bristly; first longitudinal vein bare. Tibiae with 
spurs and preapical bristle. 

The flies of this rather small family are found in grassy, 
shady and damp places, on windows, etc. They feed 
upon decaying animal or vegetable substances, fungi, 
excrement, etc. Many species live in caves and burrows. 
The larvae of Leria have been bred from bat and rabbit 
dung; those of Helomyza from truffles, decaying wood, 
etc. They are cylindrical, obtuse behind, more pointed 
in front; the antennae are situated upon long conical pro- 
cesses; mouth booklets large and pointed; the seven 

324 


HELOMYZID^. 


325 


abdominal segments on each side in front widened, below 
with bristly pseudopods. 

For Curtonotum, a genus with pectinate costa, see Dro- 
sophilidae. 


Fig. 131. Scoliocentra hclrola, enlarged. 

TABLE OF GENERA. 

1. A humeral bristle present. ..... 

No humeral, no propleural bristle. .... 

2. No bristle above base of front coxae (propleural). 

A bristle above base of front coxae. .... 

3. Spurs of middle tibiae curved (3 and fig. 131). 

Spurs of middle tibiae not curved. ...... 4 

4. Face much retreating in profile, the anterior oral border oblit- 

erated; four dorsocentral bristles present (2). Anorostoma. 
Face not conspicuously retreating. ...... 5 


Helomyza. 
Allophyla. 

- 

o 
Scoliocentr a - 


326 


NORTH AMERICAN DIPTRRA. 


Fig. 132. Helornyzidae. i, Leria, sp. wing; 3, Anorostoma, head; 
5, Scoliocentra helvola, middle tibia and tarsus. 

5. Eyes very small; four dorsocentral bristles; arista very long. 6 
Eyes not very small. ...... .7 

6. All the tibiae without bristles on outer side; hind femora of male 

often emarginate at base below. . Eccoptomera L,oew. 

Middle tibiae at least with bristles on outer side. . Oecothea. 

7. Four pairs of dorsocentral bristles. ...... 

But three pairs of dorsocentral bristles; third antennal joint short; 
bristles of costa small Tephrochlamys. 

8. Costal border of wings noticeably bristly (fig. 130). . Leria. 
Costal border with very small bristles. . . Heteromyza. 


LII. FAMILY CORDYLURID^E. 


^"ift- 1 3>3>- Scatophagafurcatd) enlarged; after \Vashburn. 

Squamae small, the upper one concealing the lower. 
Head seldom longer than high; eyes rounded or oval, 
bare, broadly separated by the front in both sexes; front 
almost always with well-developed bristles. Wings 
rather large; auxiliary vein always present and dis- 
tinct; first longitudinal vein never much shortened, where 
it joins the costa never with bristle; basal cells rather 
large, always complete; first posterior cell seldom nar- 
rowed in the border or closed; abdomen with more than 
four visible segments. 

Some of the flies of this group are easily confounded 
with those of the Anthomyidae, but an attentive exam- 
ination of the squamae, the number of segments of the 
abdomen and costa will usually resolve doubt of their 
correct location. The flies are often of considerable size 
for Acalypterates, never very small. 

The family has been called the Scatomyzidae by Becker, 
who has thoroughly studied and monographed the Ku- 


328 


NORTH AMERICAN DIPTERA. 


ropean forms. But there is reason in the objection to the 
use of a term derived from a generic name which is clearly 
a synonym. The name Cordyluridse, applied by Loew, 
is the oldest name otherwise, and must take precedence 
over Scatophagidse, which some authors have used. 
Many of the new genera erected by Becker have been 


Fig. 134. Cordyluridse. Scatophaga, male; 2, Acicephala polita, 
head; 3, Pselaphephila similis, head; 4, Orthoch<zta(l}gilvipes, head; 
5, Spathiophora, sp. head; 6, Parallelomma varipcs; 7, Hydromyza 
conflnens, head. 

recognized in North America within recent years, and 
doubtless others will be, since the family has received 
comparatively little study with us. For further study of 
the group, the reader is advised to procure his paper. I 
give only such genera in the following table as have been 
authoritatively recognized from North America, the 


CORDYLURIM;. 


329 


characters drawn chiefly from Becker's table. Many of 
the flies/ especially those of Scatophaga, are frequently 
found about excrement; some feed upon other insects 
which they capture. Many species of Cordylura and their 
allies are collected in meado\vlands and moist places. 
The larvae of some live in the stems of plants and some, 
it is said, have been bred from the larvae of Noctua. 

TABLE OF GENERA. 

1. Prothoracic and stigmatic bristles absent; thorax with five dorso- 

central bristles, or, if fewer, the palpi broad; at least four scu- 
tellar bristles present; wings usually long. .... 2 

Prothoracic and stigmatic bristles present usually; when absent 
the thorax usually nearly bristleless; one to three sternopleural 
bristles present; one to five dorsocentrals, the scutellum with 
from one to four. . . .* . . . . 3 

2. Moderately large to small species; males more thickly haired than 

the females; face but little excavated in profile; third antennal 
joint rounded, with a bare or plumose arista; palpi long and 
slender; five dorsocentrals present (1, and fig. 133). 

Scatophaga. 
Head broad j'palpi more or less dilated. ..... 9 

3. Front femora on the inner side with a double row of bristles. 13 
Front femora at the most with a single row of bristles. . 4 

4. Palpi small, slender. ........ 5 

Palpi long, flattened, leaf-like; eyes oval; antennae long, the dis- 
tal end angular; abdomen not noticeably short (3) . 

Pselaphephila. 

5. Palpi with a long, terminal bristle; one sternopleural bristle; arista 

plumose or strongly pubescent; costa of wings hairy or pectin- 
ated; third vein straight or gently curved. ... 6 
Palpi not with long terminal bristle one to three sternopleural 
bristles present. ......... 8 

6. Arista plumose; femora and tibiae with strong bristles; five dorso- 

pleural bristles; usually shining black species. ... 7 

Antennal arista slender, scarcely thickened at its base, short or 

long haired; femora and tibiae long and slender, and but little 

bristly; from one to five dorsocentrals; yellow and black species. 

Parallelomma . 


330 


NORTH AMERICAN DIPTERA. 


7. Head noticeably longer than high; face much retreating (2). 

Acicephala. 

Head scarcely longer than high; face gently retreating in profile. 

Cordylura. 

8. One sternopleural bristle; eyes but little higher than broad; anten- 

nae as long as the face; oral margin with but one, anteriorly di- 
rected principal bristle on each side; arista distinctly haired; 
five dorsocentrals; moderate sized, shining yellow flies. 

Meg-ophthalma. 

Two sternopleural bristles; antennae as long as the face, third joint 
rounded, strongly pubescent; hind tibiae with two pairs of bris- 
tles on outer side; shining black, small species. 

Hexamitocera. 

Three sternopleural bristles; five dorsocentrals ; arista distinctly 
hairy ; four scutellar bristles ; hind tibiae with three pairs of 
bristles; moderate sized, thickly hairy, gray flies. 

Orthochseta. 

9. Eyes and head round; five dorsocentral bristles. 10 
Eyes and head oval, higher than long; a single dorsocentral bris- 
tle; cheeks broad; proboscis thick and swollen; oral border with 
one short bristle on each side; antennae short, distally rounded; 
abdomen flat; hypopygium only a little prominent; rather large; 
bare, ashy gray flies (7). .... Hydromyza. 

10. Front tibiae on the inner side with a short, rectangular spine in 
addition to the terminal bristles. . . Acanthocnema. 
Front tibiae without such bristle; male hypopygium with long 
tufts of hairs; third antennal joint somewhat elongated; with a 
sharp, upper distal angle; oral border with many thickl) 7 stand- 
ing bristles. Pogonota. 

Front tibiae without such bristles; male hypopygium without long 
tufts. ........... ii 

n. Third antennal joint rounded anteriorly; eyes somewhat obliquely 

oval; cheeks small; face very short; oral border with a single 

bristle on each side; proboscis thickened; legs but little bristly; 

femora somewhat thickened. . . . Microprosopa. 

Third antennal joint with a sharp anterior angle. . . 12 

12. Acrostical bristles in more than two rows: thorax and legs thickly 

haired; bristles of oral border numerous; femora strong, with 
fine hair and weak bristles; cheeks broad (5). Spathiophora. 
Acrostical bristles in two rows; mesonotiim and legs sparsely and 
not long haired; antennae small, with sharp tip; cheeks not 
broad; oral border with bristles on each side; small, short, 
gray-dusted flies (C/i cztosa, Opsioinyia}. . Tricopalpus. 

13. Under side of head with about ten bristles. . Plethochseta. 
Under side of head with about four bristles. . Pycnoglossa. 


LIII. FAMILY ANTHOMYID^E. 


Fig. 135. Spilogaster, species; enlarged. 

Small to moderately large flies, often resembling the 
common house-fly, usualty non-metallic in color. Anten- 
nal arista plumose, pubescent or bare; eyes hairy or bare; 
males often holoptic, sometimes broadly dichoptic, the 
females always dichoptic; abdomen composed of four or 
five segments; the male genitalia often with subanal ap- 
pendages: first posterior cell of wings broadly open; bris- 
tles of bod}- often weak; squamae usually of considera- 
ble size. 

331 


332 


NORTH AMERICAN DIPTERA. 


The above definition will, in most cases, distinguish 
the members of this large family of inconspicuously col- 
ored flies. Its limits, however, are not sharp; with the 
true muscids it is connected by Muscina and allied forms; 
with the Cordyluridse by Fuccllia, etc. When one has 
become tolerably well acquainted with the allied fa mi- 


Fig. 136, Anthomyidae. i, Hyetodesia (Phaonia) luconim, head, 
from front; 2, Schoenomyza chrysostoma, head, from in front; 3, Cce- 
nosia cinerea, head; 4, Lasiops spiniger, wing; 5, Lasiops spiniger; 
head; 6, PhyUogaster cordyluroides, head; 7, Pfomalomyia (Fannia] 
scalaris head; 8, Homaloinyia scalaris, wing; 9, Ophyra aenescens, 
head; 10, Spilogaster, species, head; u, Spilogaster, wing; 12, Lenco- 
melina, species, wing; 13, Leucomelina, antenna; 14, Lispa uliginosa, 
head; 15, Lispa, species, head from in front; 16, Limophora exul, head. 


ANTHOMYID^S. 


333 


lies, he will seldom be much in doubt as to the proper 
location of his specimens here. The contiguity of the 
male eyes, together with the open first posterior cell and 
large squamae, is always decisive. Not a few of the spe- 
cies are common about houses, outbuildings, etc., and 
some of them are among the worst enemies to garden 
vegetables that the agriculturist has to contend against. 

In the larval stage, the great majority of the species 
are vegetable feeders, either in living or decaying mate- 
rial. The larvae of species of Spilogaster, Hydrot&a, Hy- 
lemyia and Ccenosia have been found in dung or manure; 
those of Hydrot&a, Ophyra, An thorny ia, Homalomyia, etc., 
in decaying vegetable material; those of Hylemyia, An- 
thomyia, Homalomyia, etc., in the nests of various hymen- 
optera ; those of Mydcsa in Spermophila and Mimus. 
Larvae of various species of Phorbia are very destructive 
to growing radishes, onions, cabbage, etc., feeding upon 
the roots. The larvae are either slender and cylindrical, 
or flat and oval, with four rows of thread-like processes 
on the segments. Both types are amphipneustic, and 
are always provided with two chitinous mouth-hooklets. 
The puparium is oval in the smooth cylindrical forms, 
flattened in the others. 

Squama and antisquama, or tegula and antitegula, 
are the terms proposed by Osten Sacken to indicate 
respectively the lower and upper scales. 

TABLE OF GENERA. 

REVISED BY PROF. C. F. ADAMS. 

1. Front narrow in the male, not more than one-fifth of the width of 

the head; often holoptic or subholoptic. .... 2 

Front in both sexes wide, including at least one-fourth of the width 

of the head in the male. ....... 27 

2. Squama larger than the antisquama. . 3 
Squama and antisquama of nearly equal size, neither large. . 17 


NORTH AMERICAN DIPTERA. 

3. Proboscis projecting, horny, the labella slender and pointed, turn- 

ed backward, hook-like; arista pubescent; eyes bare; moderate 

sized, blackish species. .... Drymeia. 

Proboscis not horny and hook-like. ..... 4 

4. Abdomen of male ovate or conical; second segment not longer than 

the third, the first segment usually imperceptible. . . 5 

Abdomen of male elongate, the second segment longer than the 
third; first segment usually distinctly visible. ... 12 

5. Eyes pilose (1) (Phaonia] Hyetodesia. 

Eyes bare. .......... 6 

6. Arista plumose. ......... 7 

Arista bare or pubescent. ....... 8 

7. Abdomen ovate, not spotted. ..... Mydaea. 

Abdomen subconical, usually spotted (1O, 11, fig. 135.)- 

Spilogaster. 

8. Front femora of the male with tubercles or emarginations below, 

or otherwise peculiarly constructed; front tibiae often with 
emarginations; hind femora often arcuate; middle and hind 
tibiae sometimes with tufts of hairs; black or blue-black flies, 

often pollinose Hydrotaea. 

Front femora simple in both sexes. ..... 9 

9. Abdomen shining black or metallic black (9). . Ophyra. 
Abdomen not shining black or metallic, and with markings. 10 

10. Vibrissae at some distance above oral margin. Brachyophyra. 
Vibrissae inserted at oral margin. . . . . . .11 

11. Fourth vein nearly or quite straight (16).* . Limnophora. 
Fourth vein distinctly curved forward (12, 13). Leucomelina. 

12. Eyes pilose. ....... Trichophthicus. 

Eyes bare. .......... 13 

13. Anal cell short; axillary vein roundly curved toward it (7, 8). 

Homalomyia. 
Anal vein long, often reaching the wing margin. . . 14 

14. Arista plumose (28, 29). .... Hydrophoria. 
Arista bare or pubescent. ....... 15 

15. Oral margin and under side of head thickly clothed with bristly 

hairs Pogonomyia. 

Not thickly covered. . . . . . . . .16 

* Compare Hammomyia. 


ANTHOMYID^. 


335 


Fig. 137. Anthomyidae. 17, Pentacricea aldrichi, abdomen; 18, 19, 
Rremomyia humeral is, abdomen and head; 20, Dexiopsis lacteipen- 
nis, head from in front; 21,22, Hammomyia unilineatas, wing and 
head; 23, Caricea insignis, leg; 24, Phorbia brassicce, abdomen; 25, 
Tetrachccta unica, head; 26, Hoplogaster nigritarsis, wing; 27, Pogo- 
inyia bicolor, head; 28; 29, Hydrophoria dirisa, wing, head; 30, Cho- 
ristoina pokornyi, wing; 31, Anthomyia radicum, head; 32, Hylemyia 
setivcntris, head. 


16. Proboscis slender, nearly as long as the thorax. Dolichoglossa. 
Proboscis not unusually long (31). . . . Anthomyia. 

17. Eyes pilose (4,5). ....... Lasiops. 

Eyes bare. ...... 18 

18. Arista plumose. ......... 19 

Arista bare or pubescent. ....... 20 

19. Front prominent, without white spots above antennae; male with- 

out subanal appendages; female without decussating bristles in 
front of ocelli; body (except in vittipes} marked with shining 
black stripes or spots. .... Eustalomyia. 

Front not prominent; males usually with subanal appendages; fe- 
male usually with cruciate bristles in front of ocelli; body with- 
out shining black stripes or spots (32) . . . Hylemyia. 

20. Abdomen of male subcylindrical. ... 21 
Abdomen long, depressed. ....... 25 

21. An additional macrochaeta above the first posthumeral (18, 19). 

Eremomyia. 

Without such macrochastas, or with a bristly hair instead. . 22 


336 


NORTH AMERICAN DIPTERA. 


22. Sides of face and cheeks wide; front of female narrower than 

either eye; wings without costal spine (21, 22) Hammomyia. 

Either the sides of the face or the cheeks narrow; front of female 

often wider than eye; wings usually with costal spine. 23 

23. Legs wholly or partly rufous or yellow (27). . Pegomyia. 
Legs wholly black. . . 24 

24. The anal vein attains the wing margin. . . Chortophila. 
The anal vein does not reach the wing margin. . . Azelia. 

25. The eyes occupy the upper two-thirds of the sides of the head. 26 
The eyes do not occupy the upper two-thirds of the sides of the 

head (24). .... . Phorbia. 

26. The anal vein reaches the wing margin. . Prosalpia. 
The anal vein does not reach the wing margin. . Ccelomyia. 

27. Anterior cross-vein situated before the end of the first vein. 28 
Anterior cross-vein under or beyond the end of the first vein. 30 

28. Wings without costal spine. .... 29 
Wings with costal spine (SO ) . . Choristoma. 

29. Squamae small, equal Euryomma. 

Squamae large, the under longer than the upper. Charadrella. 

30. Palpi unusually broad at tip (14, 15). . . . Lispa. 
Palpi not unusually enlarged at tip. ... 31 

31. Squamae equal (2).* , Schcenomyza. 
Squamae unequal, the lower projecting beyond the upper. 32 

32. Head narrow, antennae not elongate; tibiae with very long bris- 

tles (23). Caricea. 

Not having all the above characters. ... 33 

33. Four post sutural macrochaetae (25). . . . Tetrachseta. 
With less than four post siitural macrochaeta. ... 34 

34. Five abdominal segments visible (17). . . Pentacricia. 
Only four abdominal segments visible. 35 

35. Abdomen cylindrical, incrassate posteriorly; hypopygium prom- 

inent (6) . (Compare Hoplogaster 26). Phyllogaster. 

Abdomen not cylindrical or incrassate behind. ... 36 

36. Head much broader than high (2O). . . . Dexiopsis. 
Head not markedly broader than high. . . 37 

37. Frontal triangle large, with straight sides, the apex blunt, reach- 

ing the base of the antennae Limnospila. 

Triangle with concave sides, the apex sharp, seldom reaching the 
base of the antennae (3) Coenosia. 

* Fucellia. The members of this genus, which has been referred to 
various families of acalyptrates, are iound often in abundance along 
sea-shores, about decomposing material which has been thrown up by 
the waves. They are of moderate size, blackish gray in color, and 
will be easily recognized in the males by the hind femora having a 
bunch of bristles near their base, inserted on a short emargination; 
the face has numerous vibrissal bristles; the arista is bare, etc. w. 


LIV. FAMILY 


Fig. 138. Htnnatobia serrata, male; enlarged. 

Rather small to moderately large, never elongate, thin- 
ly hairy or bare flies. Antennal arista plumose to the 
tip; sometimes above only, and rarely bare, in which 
cases the absence of bristles on the abdomen, except at 
the tip, together with the narrowed first posterior cell, 
characters distinctive of the group, will distinguish the 
flies belonging here from their allies. Eyes of the male 
approximated or contiguous; front of female broad. 
Eyes bare or hairy. Abdomen composed of four visible 
segments. Genitalia not prominent. 

Like the Sarcophagidae, the species and individuals of 
this family are common everywhere. The common house- 
fly, the type of the group, has a cosmopolitan distribu- 

337 


,^8 NORTH AMERICAN DIPTKRA. 

v_ J O 

tion wherever man exists. Other species, which are 
scarcely less common and widely distributed, are the 
common blue-bottle and blow-flies, members of the gen- 
era Lucilia and Calliphora. As widely known are the 
stable -fly or cattle -fly, Stomoxys, and the horn -fly, 
H&matobia. 

The larvae of the house-fly live, for the most part, in 
dung or manure, but will thrive in almost any kind of 
filth; I have reared them from the decaying material in 
the bottoms of spittoons filled with tobacco. The female 
lays about one hundred and twenty-five eggs, which 
hatch in one or two days, according to the weather. The 
larvae attain their full development in from four to seven 
days, and then, crawling into some secluded place, trans- 
form into pupae, from which they emerge in about six 
days as mature insects, those of the autumn broods re- 
maining over winter as puparia. In partially secluded 
spots the mature fly will sometimes survive the winter. 
The cluster-fly, Pollenia rudis, is yet more remarkable in 
this last respect. Often in early spring, or even during 
mild days of the winter they may be observed crawling 
about over the snow in numbers. They are stupid and 
slow and have received the name of cluster-flies from 
their habit of congregating in clusters about dwellings. 
They resemble a blow-fly somewhat; but will be distin- 
guished by the presence of short, depressed, sparse light- 
colored hairs on the thorax. The larvae of species of 
Calliphoia, especially of C. vomitoria, are better known, 
perhaps, than those of any other insect. They are the 
common blow-fly maggots of fresh and decaying meats 
and vegetables. The cooking of corned beef or turnips 
or cabbages during warm weather is sure to attract num- 
bers of these insects, which are quite noticeable for their 
loud humming and headlong flight. In the arid regions 
of northern Wyoming the writer has seen them in extra- 


MUSCID/E. 


339 


ordinary numbers, many miles from the nearest human 
habitation. Hither their eggs or the newly hatched larvae 
are deposited upon meats, and only a day or two is suffi- 
cient to transform the material into a creeping mass of 
disgusting maggots. The larvae of species of this genus 
sometimes have habits similar to those of the screw- 
worm flies. The blue-bottle and green-bottle flies have 
habits identical with those of Calliphora, but the}' are not 
so common. The screw-worm fly ( Chrysomyia macellaria), 
an insect common over nearly all of North and South 
America, is bright shining green or golden green in 
color, but will be distinguished from the blue-bottles by 
the presence of blackish stripes on the thorax. It depos- 
its eggs, which hatch almost immediately, in decompos- 
ing matter, as do other members of the family, but it will 
also lay them in the ulcers of cattle, or wounds, or at 
the orifice of the human nose, especially when attracted 
thereto by a fetid breath. The larvae in these cases 
quickly penetrate within the nasal and frontal sinuses, 
sometimes to the number of a hundred or more, quickly 
producing fever, extended ulceration and in frequent 
cases, death. These cases of Myiasis, as the affection is 
called, are not very frequent in North America, but have 
been not seldom recorded from South America. Sarco- 
pliila Wohlfahrti , a European species, has similar habits. 
The group Stomoxyinae includes about thirty known 
species, all blood-sucking in habit, among which are the 
notorious stable-flies, horn-flies and tsetse flies. The 
horn-fly (ffcsmatobia serrata*} is a comparatively recent 

* Speiser, and, following him, Bezzi would call this genus Siphona, 
a name hitherto applied to a genus of proboscideous Tachinidae, claim- 
ing that the type was H. serrata (irritans} ; but I quite agree with 
Austen that the case is by no means proven, and, even if it were, I do 
not think it calls for such a revolutionary change in these long estab- 
lished names. 


NORTH AMERICAN DIPTERA. 

introduction from Europe, the first known American 
specimens having been noticed in eastern Pennsylvania 
in the spring of 1887; it has now extended over nearly 
all of North America. An allied species is indigenous to 
North America, living among the moose of the northern 
woods. The tsetse flies* are perhaps the most famous of 
the group. The diseases produced by the microparasites 
(trypanosomes) transferred into their victims by their 
elongated piercing proboscis are so dire in their results 
that the regions certain species inhabit are rendered al- 
most uninhabitable by the domestic animals. The dis- 
eases also afflict certain wild animals, though with less 
fatal results. The microparasites are, themselves, ap- 
parently not regenerated in the flies, as is the case with 
the mosquitoes, but are transferred by them shortly after 
biting diseased animals to healthy ones. The fatal 
'sleeping sickness' (trypanosomiasis) in man is occasion- 
ed in the same way by the bites of Glossina palpalis. The 
larvae of Glossina are born when well developed and ready, 
or about to be ready, to become pupae, resembling those 
of the Hippoboscidae in this respect. 

The limits of the Muscidae, both from the Sarcopha- 
gidae and the Anthomyidae, are quite elusive and uncer- 
tain; indeed they seem almost impossible of definition 
save by the aid of artificial and trivial characters. 
Girschner, and some other authors following him, would 
unite the Calliphorinae, that is those with hypopleural 
bristles, with the Sarcophagidae or Tachinidae. The log- 
ical sequence would be to unite the Muscinae with the 
Anthomyidae, abandoning the family. His views, how- 
ever, have not been generally adopted. One genus with 
bare arista has been generally united with the family, so 
that the ultimate distinction from the Tachinidae would 

* An amateur dipterist has recently proposed in all seriousness to 
separate the tsetse flies into an independent family, the Glossinidse ! 


MUSCID^. 


341 


seem to be the lack of hirsuteness of the abdomen. On 
the other hand, there seems to be no real distinction from 
the Anthomyidae, unless the almost evanescent curvature 
of the fourth vein be considered as such. 


Fig. 139. Muscidae. i, Chrysomyia; 2, 3, Pollenia; 4, Mesembri- 
nella; 5, Graphomyia; 6, Myiospila; 7, 8, Morellia; 9, Muscina; 10, 
Clinopera. 


NORTH AMERICAN DIPTKRA. 

The larvae of Muscina have been found in decaying 
vegetables, dung, fungi and the larvae of various lepi- 
doptera, a remarkable diversity of habits. The larvae of 
Graphomyia and Mesembrina have been found in horse 
and cow dung. 

TABLE OF GENERA. 

1. Proboscis long, slender, directed forward; arista pectinate, or 

sometimes with a few hairs below also. .... 2 

Proboscis not elongate, the labella fleshy and not adapted for 

piercing. . .... 3 

2. Palpi nearly as long as the proboscis (Lyperosia; fig. 146). 

Hsematobia. 
Palpi much shorter than the proboscis. . . . Stomoxys. 

3. Arista bare; distal section of the fourth vein broadly curved at its 

end Synthesiomyia. 

Arista pectinate. ...... Hemichlora. 

Arista plumose. ......... 4 

4. Hypopleurse with a vertical row of bristles. .... 5 
Hypopleurse not with a row or tuft of bristles. ... 14 

5. Eyes pubescent Tyreomma. 

Eyes bare. .......... 6 

6. Vibrissal angle at a considerable distance above the oral margin; 

angle of fourth vein rounded or rectangular. ... 7 
Vibrissal angle near oral margin. ...... 8 

7. Thorax and abdomen with depressed hairs or tomentum among 

the bristles, especially noticeable in the intraalar region; dark- 
colored, slow moving 'cluster flies' (2, 3) . Pollenia. 
Thorax and abdomen not with such hairs; mesonotum distinctly 
striped; bright metallic flies (1). . . Chrysomyia. 

8. Bend of fourth vein angular, or with the angle slightly rounded. 9 
Distal section of fourth vein with a broad curve ; cheeks bare ; 

rather large flies, reddish or yellowish, with the distal portion 
of the abdomen metallic (4). . . . Mesembrinella. 

6. Dorsocentral bristles present. ...... 10 

Dorsocentral bristles absent. . . . Chloroprocta. 

10. Arista .usually plumose for not more than two-thirds its length; 

hypopygium prominent. ..... Cynomyia. 

Arista plumose to tip; hypopygium not prominent. . . u 

11. Mesonotum not flattened behind the transverse suture. . 12 
Mesonotum flattened behind the transverse suture. . . 13 


MUSCID^. 


343 


12. Posterior dorsocentral and acrostical bristles well-developed and 

constant; cheeks hairy; third longitudinal vein spinulose at base 

only. . Calliphora. 

Posterior dorsocentral and acrostical bristles constant and well- 
developed; cheeks bare; first section of the third vein for a part 
or all its length spinulose. ..... Lucilia. 

13. Posterior dorsocentral and acrostical bristles inconstant and une- 

qually developed; cheeks hairy; first section of third vein in 
large part spinulose. ...... Phormia. 

Posterior dorsocentral well, the acrostical bristles unequally de- 
veloped, cheeks hairy; first section of third vein in large part 
spinulose. ... . Protocalliphora. 

14. Middle tibiae with a prominent bristle on its inner, flexor surface 

beyond the middle. .... .... 15 

Middle tibiae withoiit such bristle. ..... 17 

15. Termination of first longitudinal vein nearly opposite the middle 

of the penultimate section of the fourth vein; distal section of 

the latter forming a broad curve. . Mesembrina. 

Termination of first vein nearly opposite the anterior cross-vein. 16 

16. Sternopleurae with one bristle in front and two behind; angle of 

fourth vein rounded. .... Pseudopyrellia. 
Sternopleunue with one bristle in front and three behind; last sec- 
tion of fourth vein forming a broad, gentle curve. Pyrellia. 

17. The last section of the fourth vein has a rounded angle; sterno- 

pleurae with one bristle in frontand two behind; never metallic 
species. ......... Musca. 

Last section of fourth vein broadly curved near its middle, or with 
an anterior flection at its tip. ...... 18 

18. Byes pubescent. ......... 19 

Eyes bare. .......... 20 

19. Antennae separated at their base by a distinct carina; sternopleu- 

rae with two bristles behind, none in front; body gray or partly 
rufous with a well-defined black pattern (5). Graphomyia. 
Antennae not separated at base by carina; sternopleurae with two 
bristles in front and two behind; body not metallic colored. 

Myiospila. 

20. Last section of fourth vein with a broad curvature near its middle. 

the cell opening rather narrowly; grayish or metallic spotted 

species (1,8) Morellia. 

Last section of fourth vein curved forward, often slightly, beyond 
its middle or at the tip, the cell broadly open. . . 21 

21. First longitudinal vein ends beyond the middle of the wing; one 

or more well-developed pairs of anterior acrostical bristles (9) . 

Muscina. 

The first vein ends before the middle of the wing; no anterior 
acrostical bristles (1O). . ... Clinopera. 

Soniotnyia, Cyrtoneurina and Hyadesi myia are not included in the 
table, because of insufficient data. 


LV. FAMILY 


Fig. 140. Cuterebra buccata, enlarged; after Washbnrn. 

Flies of moderate to large size, thick-set, usually more 
or less pilose. Head large, trie lower part more or less 
swollen. Antennae short, three-jointed, decumbent, and 
more or less sunken in the facial groove or grooves; 
arista bare or plumose. Mouth opening small, the 
mouth-parts sometimes rudimentary, never large. Front 
broad in both sexes, in the male broader in front. Eyes 
comparatively small, bare. Ocelli present. Thorax ro- 
bust, with a distinct transverse suture. Abdomen short, 
conical or but little elongated; genitalia of the male hid- 
den, the ovipositor sometimes elongated. Squamae usu- 
ally large; sometimes small. Venation of the wings 
muscid-like, in most cases the first posterior cell narrow- 
ed or closed; anal cell small, sometimes indistinct; discal 
cell sometimes absent. 

This family, though of small size comparatively, is of 
the greatest fnterest by reason of the habits of the larvae, 
all of which that are known being parasitic upon mam- 
mals. The adult flies often have vestigial mouth-parts, 

344 


345 

and devote the whole of their brief existence to the labors 
of procreation. Only about seventy-five species are 
known, and they are generally called bot-flies, though 
the name is frequently applied especially to the bot-fly 
of the horse. Parasitism occurs in three principal ways: 
in the stomach and digestive tubes', in tumors formed by 
the larvae under the skin, and in the pharyngeal and 
nasal cavities. With but few exceptions each species is 
confined to a single species of mammal, and each genus 
or each group of allied species is parasitic in the same 
way upon allied animals. Seven species of Gastrophilus 
are found in the stomach and intestines of the horse and 
ass. Thirteen species of Hypoderma are known to live 
under the skin of the horse, the ox, the buffalo, the sheep, 
the goat, four species of antelope, and the musk-deer. 
Two species of CEstromyia likewise infest the skin of La- 
gomys and Hvpod&us. CEdamagena tarandi is parasitic in 
great numbers in the skin of the reindeer in both Siberia 
and boreal America. Four or five species of CEstrus live 
in the nasal sinuses of sheep, antelope, and horse (Rhin- 
cestrus}. One species of Cephalomyta lives in the nasal 
cavities and throat of the camel and buffalo. Six or 
seven species of Cephenomyia have been found parasitic 
in the pharyngeal cavities of various Cervids, while va- 
rious species of Cuterebra, Bogeria and Rogenhofera have 
been bred from the skin or scrotum of rodents and 
opossums. Two species of Dermatobia have been obtain- 
ed from the skin of dogs, cattle, cats, deer, and probably 
apes and man. The eggs or young larvae are, it is be- 
lieved, in all cases taken into the mouth by the animals 
which they infest, going thence to the sinuses, pharynx 
or stomach; or, through the tissues of the body, to the 
skin. Perhaps those living within the scrotum may reach 
their abiding place by a more direct route. 

32 


346 


NORTH AMERICAN DIPTERA. 


Fig 141. CEstridae. I, Gastrophilus, wing; 2, Gastrophilus, anten- 
nae; 3, Cuterebya, antennas; 4, Cuterebra, front tarsus; 5, Cuterebra, 


wing, 


/ " * 

; 6, Dermatobia, wing; 7, Dennntobia, front tarsus. 


TABLES OF GENERA. 

IMAGINES. 

1. Month-parts very small, vestigial; arista bare. ... 2 
Proboscis genicnlate, inserted in a deep slit; female without extri- 
cate ovipositor; first posterior cell narrowed or closed; arista 
bare or plumose; facial grooves approximated below, enclosing 
a narrow median groove or depressed surface; squamae large. 6 

2. The fourth longitudinal vein runs straight toward the border of the 

wing, i. e. the apical cross-vein is obsolete, and the first poste- 
rior cell is not narrowed; squamae small; female ovipositor elon- 
gate; larvae in stomach and intestinal canal (1, 2). 

Gastrophilus. 

The fourth vein turns forward to form the apical cross- vein, closing 
or narrowing the first posterior cell. ..... 3 

3. Facial grooves approximated below, leaving a narrow median 

groove or depression. ........ 4 


Facial grooves remote, enclosing between them a broad, gently 
arcuate, shield-shaped surface ; squamae large; female with 
elongate ovipositor; larvae hypodermatic. ... 5 

4. First posterior cell closed and petiolate; body nearly bare. CEstrus 
First posterior cell narrowly open; body pilose. Cephenomyia. 

5. Palpi wanting Hypoderma. 

Palpi small, globular. ...... CEdamagena. 

6. Arista bare, short and stout; wings without stump at angle of 

fourth vein. ........ Bogeria. 

Arista pectinate above. ........ 7 

7. Tarsi broad and flattened, hirsute (3, 4, 5); alulae large. 

Cuterebra. 

Tarsi slender, not hirsute; third joint of antennae more elongate; 
front prominent anteriorly; alulae of moderate size (6, 7). 

Dermatobia. 


1. Last abdominal segment free, broadly attached. ... 2 
Last abdominal segment (twelfth) retractile within the preceding, 

small and distinctly constricted. ..... 7 

2. Larvie with two pairs of chitinized jaws; that is with two outer 

mouth-hooklets, and two inner, straight, triangular points 
( Horses) ........ Gastrophilus. 

Larvae with two or no mouth-hooklets. ..... 3 

3. Larvae on the median segments with dorsal, spindle-shaped tuber- 

cles; one pair of mouth-hooklets present. . . .4 

Larvae without such tubercles; one pair or no mouth-hooklets pres- 
ent. 5 

4. Antennae broadly separated; body oval, strongly convex above, flat 

below (Sheep) Oestrus. 

Antennae approximated or contiguous; body elongated, somewhat 
broader in front than behind (Deer) . . Cephenomyia. 

5. No mouth-hooklets. . ....... 6 

Two small mouth-hooklets present (Rodents). Oestromyia 

6. Bristly covering alike above and below (Reindeer) . Osdamagena. 
Bristles stronger below than above (Ox, etc.) Hypoderma. 

7. Larvae oval (Rodents, Marsupials) .... Cuterebra. 
Larvae club-shaped, more slender posteriorly (Artiodactyls, Carni- 

vora. Primates). Dermatobia 


LVI. FAMILY SARCOPHAGID^, 


Fig. 142. Sarcophaga saracenia, enlarged. After Washburn. 

Usually thick-set, moderately large to rather small 
flies. Front in both sexes broad, though usually some- 
what narrower in the male. Arista of the antennae plu- 
mose to the middle or a little beyond, the distal portion 
bare; this last character alone is the ultimate distinctive 
one of the group. Abdomen composed of four visible 
segments, with the macrochaetse usually confined to the 
distal portion, though sometimes occurring on the mar- 
gin of the second and following segments and very rarely 
on the disk; male hypogygium often prominent. First 
posterior cell of the wings always much narrowed or 
closed. 

348 


SARCOPHAGID^. 


349 


This family of flesh-flies, as they are often called, 
though comprising but comparatively few genera, has a 
great number of species and individuals. For the most 
part the species are tolerably uniform in coloration, and 
at first sight seem scarcely distinguishable, having a 
gray striped thorax and marmorate abdomen. The more 
metallic colored species of Cynomyia and Onesia are ex- 
ceptions. The flies are found everywhere, about decay- 
ing vegetation, especially fruit, excrement, decomposing 
carcasses, etc. 

The larvae are polyphagous in habit, feeding upon de- 
caying animal or vegetable matter, or living parasitically 
in the flesh of different animals, in the nasal cavities of 
man and other animals, in ulcers, etc. The larvae of 
Cynomyia live in great numbers in the decomposing car- 
casses of vertebrate animals. The larvae of Sarcophaga, 
which are often extruded by the parent fly alive, have 
been found under the skin of turtles, in the stomachs of 
frogs; and most of the cases of myiasis that have been 
reported, other than those due to the larvae of Chrysomyia 
and Calliphora, have been caused by the maggots of the 
species of this genus and those of Sarcophila. The larvae 
of several species have been found in snails, in beetles, 
grasshoppers, the pupae of moths, etc. 

The Sarcophaga larvae are rounded, thinner anteriorly 
and amphipneustic. The antennae are short, thick, cy- 
lindrical, divergent, wart-like tubercles, each with two 
ocellus-like chitinous rings at the tip. The mouth-hook- 
lets are distinct, strongly curved, and separated from 
each other. The abdominal segments are distinctly dif- 
ferentiated by transverse swellings, and are each pro- 
vided with a girdle of spines. The hind stigma-plate is 
situated in a deep cavity, which is formed by the last 
segment alone. The anal swelling is two-pointed. The 
puparium is oval. 


350 


NORTH AMERICAN DIPTKRA. 


Fig. 143. Peckia prtzceps, enlarged. 

TABLE OF GENERA. 

1. First posterior cell closed or much narrowed in the margin. 2 
First posterior cell open. ....... 5 

2. Second and third abdominal segments with discal and marginal 

macrochaetae. Paramintho. 

Second and third segments without discal macrochaetae. . 3 

3. First vein bristly. ....... Johnsonia. 

First vein bare. ......... 4 

4. Arista bare or pubescent. .... Hesperomyia. 
Arista distinctly plumose. .... Sarcophilod.es. 

5. Abdomen black or metallic, unicolorousand but slightly pruinose. 6 
Abdomen gray or partly ochraceous, with black reflecting spots. 8 

6. Hypopygium very prominent; legs more or less hairy. . 7 
Hypopygium concealed; legs not hairy; curvature of fourth vein 

with an obtiise angle and without stump. . . Onesia. 

7. Abdomen usually black; tibiae densely hairy. . . Peckia. 
Abdomen metallic; tibiae with short hairs (see Muscidae). 

Cynomyia. 


SARCOPHAGID^. 

8. All the tibiae with a comb-like row of long stout bristles externally. 

Theria. 
Without such bristles, or with irregularly placed ones. . 9 

9. Cheeks with long bristly hairs below 10 

Cheeks with short pile. ..... Erythrandra. 

10. Last section of fourth vein more oblique than the posterior cross- 

vein. . . . . . . . . . . .11 

Both veins in nearly the same straight line; two orbital bristles in 
the female; none in the male. . . . Sarcophaga. 

11. Two orbital bristles in each sex. . . . Sarcophagula. 
Two orbital bristles in the female, male? . . Helicobia. 

Sarcodexia and Sarothromyia are not included in the table for lack 
of sufficient data. 


LVII. FAMILY 

Rather small to large, chaetophorous flies, thinly or 
not at all pilose, usually more elongate than the Tachi- 
nidae. Eyes of the male contiguous, or more approx- 
imated than those of the female; pubescent or bare. 
Front with a row of bristles on each side descending to, 
but not below, the base of the antennae, save rarely. 
First joint of antennae short; second usually shorter than 
the third; third joint more or less elongate, sometimes 
short, decumbent. Arista bare, pubescent or pilose, with 
two or three visible joints. Face always with a well- 
marked median depression, with a more or less distinct 
median ridge or carina. Proboscis sometimes elongate, 
but usually short and with bread labella; palpi never 
with more than one joint, which is sometimes vestigial. 
Ocelli present. Abdomen composed of four or five visi- 
ble segments, with marginal, lateral, and usually discal 
bristles. Legs sometimes rather stout; usually elon