Samuel Wendell Williston.

Manual of the families and genera of North American Diptera online

. (page 1 of 18)
Online LibrarySamuel Wendell WillistonManual of the families and genera of North American Diptera → online text (page 1 of 18)
Font size
QR-code for this ebook


• ■ I , i ; I ; i ( I a ! i ; I ; 1 1 1 n 1 1 ;



III r I • I ■ r ; , ij



ft;;;;



iifi h

1 1 M I 1 (
. i 1 1 1 \ r



M f . '


':':




1 ' 1 1


' ' ( ' j ; ■ 1 ' ■ ' ' J ; ^ ' 1 1 ' M ' ! ' 1


1 ' 1


.V ' " 1 'i ' , " ' /' i ' 1 - ' !


1 1 1 ; 1 1 1 1 1 ' J ' 1 ■

:;ilM.n'illl.'-!'i


;: ;^'''Vi:^ -


■'■!,,


,


I ' 1 1 ' •■ ■ 1 '■■ 1


hi' '


I 1 t ■ 1 !'■


I ilri'l


1 ' 1

1 1 1 1

ill!

; ;i


P;;;'' : ■,



; M. : I ' 1 n n ' 11 I

I.I Miir, il.M|in;

M nwi;HU''ii
-Ml, pfiiii i/ii:



I , , ■ / 1 I i / i / 1 M I I




'■■■- ::S;;i;iill:liiiiiiilifi.|



M MIlrllH

;l|!M|l.l|i I
.MlilMKU ■



.1 .i(ii! !i:iMi




..,:,:„.


lltlll'i


,;i;iliin


Miin 1


I W 1 1 H 1


mni'i

(1 Mil



ii 1 1 )
'Mil
M 1 W

: . ,M 1 1 i 1

W I! Ill

llwlli
w j 1 n i


1 M 1



ilil/HlMlll I
HIM I I, H Ii M '

1 1 1 W u M I ! ■ i I ; t



r I 1 •■ I' i I ; • |.M I



I



1 H ■ ll


1 1 ■ ' n 1


'://B'X'


■ II 1 1 1 / 'M '


Mill


1 MM Ii


;l M J 1 1 1 1 1 M


.1 1 1 M 1 M 1 M

1 II M 1 Ml 1 1
Ml M 1 M ;i i



U ill ; 1 M 1 M 1
11 II 1 M ; Mill


i;j


1 Mill 1 M'fll


1 1 1



II I J '



i 1 1 , ! 1 1 11 M M M M Ml If M ' M I M M ' :
MMMI ilhMMniH(l|lni;\jM'.!l
I |Mm1 MMI M|l Mm I MMUh 'MM (M I
Ml ill Mil M MM M/ I MMIUl..

I M. li I Mir I MM I, M MMM M



Ml, M M M MIlMM Mill' I viMr
MM.M III' 11 Mil llli'M lilMh
iI'mmIiImmIiII mum I\H!11'
M'l '(MMM\|ll';'lll'l'i 11/
,'|,MIMI,|ll(.ll> llMlMtU'l

MM'iliiaiiiiilnliiMiir



ill i' Mill I'
M'll 'MM Ii
Ml I'M I! I I'
,1, I'Mill



M IMMII, IP Ml I M, Ml I M
I M I ) I 1 1 M M. M 1 1 I I I . M I • M
IMMMIM i'll'll HM'M/ i|
I II I M M / 1 MM I H M M M I M I M M
MM MM/ Ml I'- iMMMi IMIi'l
M Mil. I'M I M nil ll Mil ' (I MM
I I I M I 1 1 I I 1 M I MM I M I 1 I n M I 1 1
I'lMIIlM . .'IMI IM.lM.MIlM
iM ' M IIM I 1 M '. M 1 Mil I I M I l.i'



W'MM.I /(Ml I'
1 M i M M I M I . I M
iM.IMMI/liM M



M I i I . MMMM./IMMMM
MM, .' I' 'IIIMillllP'"
M ; M I M I'l i 1 M M I I I

iMMlUMMIlH P '"

MiiMi I iMlilIlM!: '

I I M M i M I I I M I M I ' ■

: i . M 1 1 i I . M r M r. 1 I • ■



, lilll


1, MiMiin,, i''"i "' "';


Mill il


i;i!ni;(H;/(;(;i.iui;"i

1 1 1 i 1 1 ) w 1 1 i . 1 ( M 1 1 1 ' 1 ; ' ,
iii(MiMM;i '';'!;:,,]


I ■ ' ' 1 ' '


IMl'IM M. ,1 '; MM 1, M



',| I I'M MMM II I



MMiMlnil "' I '
,WMlM.linlM
,MP/IMI'|IM1
Mill Mill IIP'' I



rb



c^9 3^<?4.5'5'




t



^



V'





/


.... wihii




Z MAft -Hj


'is'




go FEB 1402




fEB 5






'IDfJ


^9 ..




IS.F£B^2


1

L ■!




MAY 14 1952














Digitized by the Internet Archive

in 2010 with funding from

Boston Public Library



http://www.archive.org/details/manualoffamilies1896will



MANUAL



OF THE



FAMILIES AISTD GEI^EEA



OF



I^ORTH American Diptera



SECOND EDITION



REWRITTEN AND ENLARGED



BY



SAMUEL W. WILLISTON

PROFKSSOR OF PALEONTOLOGY AND ANATOMY
UNIVERSITY OF KANSAS



' K y c , " , , »



I •. :, t " i, ij t »



NEW HAVEN
JAMES T. HATHAWAY

297 CROWN ST. NEAR YALE COLLEGF

18 9 6






Kntered according to Act of Congress, in the year 1896,

By JAMES T. HATHAWAY,
In the office of the Librarian of Congress, at Washington.



c c c ' (
C c « ' t I



C ' t C 4

1 tc«-'c' '



PREFACE



Eight years ago the author of the present work published
a small volume in which he attempted to tabulate the families
and more important genera of the diptera of the United
States. From the use that has been made of that work by
entomological students, he has been encouraged to believe
that the labor of its preparation was not in vain. The extra-
ordinary activity in the investigation of our dipterological
fauna within the past few years has, however, largely destroy-
ed its usefulness, and it is hoped that this new edition, or
rather this new work, will prove as serviceable as has been
the former one. In the present work there has been an at-
tempt to include all the genera now known from north of
South America. While the Central and West Indian faunas
are preeminently of the South American type, there are doubt-
less many forms occurring in the southern states that are at
present known only from more southern regions.

In the preparation of the work the author has been aided
by the examination, so far as he was able, of extensive col-
lections from the West Indies and Central America submitted
to him for study by Dr. D. Sharp of Cambridge, England,
and Messrs. Godman and Salvin of London, together with the
extensive collections of the University of Kansas and those
from South America in the author's private cabinet, alto-
gether forming probably the largest collection of American



IV PREFACE.

Diptera ever brought together. For the descriptions of the
early stages reliance has necessarily been placed chiefly upon
the writings of Brauer. As will be seen, assistance has
been derived from the works of Schiner, Osten Sacken,
Loew, Wulp, Town send and others, although but very few
of the North American genera, aside from those of the Tach-
inidse and Dexiidse, are unknown to the writer.

The author owes his sincerest thanks to Prof. J. M. Aldrich
for the family characters and table of the Dolichopodidse ; to
Prof. V. L. Kellogg for the paragraphs on the internal anat-
omy of Diptera; to Prof. J. B. Smith for kind favors ; and to
Prof. W. A. Snow for the table of the Ortalid<3e.

Lawrence, Kans., June 10, 1896.



CORRIGENDA.
Page viii, line 9, for 'writer' read student.

X, line 10, for 'hemispherical' read spherical.
xix, line 5 from bottom, for 'Cyclorrhapha' read Orthorrhapha.
18, line 2 from bottom, insert not before 'forked' and delete from
the following line.

31, line 4 from bottom, for 'anal cell closed' read discal cell open.

32, line 2, for 'Thambeta Williston' read Diotrepha Osten Sacken.
35, line 14, for '5' read 3.

40, line 13 from bottom, insert flattened before 'cylindrical', and,
three lines below, read 'tibiae with or without spurs.'

43, last line, for 'Subula Omyia, noni. nov.' read Xylomyia Rondani.

58. line 13, for 'Orthoneuromyia Williston' readPsiLOcuRus Loew.

88, line 17 from bottom, for '64' read 67 ; line 6 from bottom for '67'
read 65.

96, line 15 from bottom, for 'Eumyidae' read Holometopa ; line 11

from bottom, for 'Schizophora' read Eumyidae.
140, line 3, for 'witli' read without.



TABLE OF COE'TEIsTTS.



INTRODUCTION,










VII


Head,








X


Mouth-parts,










XIII


Thorax,










XVII


Legs, . -










XIX


Abdomen, '










XX


Chaetotaxy,










XX


Wings,










xxm


Internal Anatomy, ....










XXVI


Collection and Preservation of Diptera,










XXVIII


Classification, .....










XXXI


BIBLIOGRAPHY, . . .










. XXXIII


TABLE OF FAMILIES,










1


Cecidomyid^,










7


Mycetophilid^, ....










13


LlPONEURID^, BlEPHAROCERID^,




.-






19


CULICID^,










20


Chironomid^, . . . • .










22


Orphnephilid.e, . . .










26


PSYCHODID^,










26


DlXID^,










28


TlPULID^, . .










29


BlBIONID^, . . • . .










37


SlMULIID^,










38


Rhyphid^, .....










40


Leptid^,










41


Stratiomyid^, . . . .










44


Acanthomerid^, ....










49


TABANIDiE,










49


ASILID^,










52


Apiocerid^,










60


Nemistrinid^, ....










60


Mydaid.e,










62


BOMBYLIID^,










63



VI



TABLE OF CONTENTS.



There viD.i;,

SCENOPINID.^,
ACROCERID^,
LONCHOPTERID.E,
EmPIDIDxE, .

dolichopodid^,
Syrphid^, .

CONOPID^, .
PlPUNCULID^,

Platypezid^,
Phorid^,

MUSCIDEA, .
Borborid^,
Agromyzid^,
Geomyzid^,
oscinid/e,
Drosophilid^,
Ephydrid^,

DlOPSID^, .

Sepsid^,

MlCROPEZID^,
PSILID^,

Ortalid^, .
Trypetid^e,

SAPROMl'ZIDiE,

Rhopalomerid^
Helomyzid^,
Heteroneurid^,
Sciomyzid^,

PhY'CODROMID^,

SCATOMYZID^,

AnTHOMYID/E,

Oestrid^, .
Sarcophagid^,

MuSCIDiE,

Tachinid^,
Dexiid^,

HlPPOBOSCID^,

Nycterybiid^,
APPENDIX,
INDEX,



68
69
70
72
72
76
82
91
98
94
95

96
101
102
104
105
107
108
HI
111
113
114
114
119
123
124
125
126
127
128
128
133
136
138
140
144
144
151
152

153

155



ikteoductio:n^.



The order of two-winged insects, known as flies or Diptera,
includes nearly forty thousand known species from different
regions of the world. Since many of the species are very small
or minute, and inconspicuous, and as the order has received
only a small share of the attention of collectors and students,
there certainly remain very many more to be yet made known.
From North America not far from four thousand species have
been studied, and we probably have as many more awaiting
discovery. Our knowledge of the dipterological fauna has
progressed with increased rapidity during the past ten or
twenty years, but vast fields for profitable study yet remain
open for the serious investigator. In North America the
results to be obtained are almost inexhaustible. Nearly every
family yet awaits the conscientious monographer. The des-
cription of new species is the much less interesting of the
work to be done, and perhaps the less profitable. At the
present time the rapidly increasing number of short papers
descriptive of new forms is rendering the determination of
species more and more difficult.

To the student beginning the study of this interesting group
of insects, some words of advice or caution may be of service.
The present work can make no pretensions to completeness
in the characterization of genera, and he should never depend
upon mere tables in the absence of other information. Doubt
of the right generic location of a specimen may often be surest
dissipated by attempting to refer it to some species. Until the
student has acquired a sort of intuitive acquaintance with the
different families the work may be somewhat tedious, but by



VIII INTRODUCTION.

perseverance he can not fail to overcome whatever obstacles
families and genera may present. He will be very much
aided at the beginning by having a tolerably large collection
at his command by which to make comparisons. Difficulties
will often disappear with positive evidence before him, where
negative characters are puzzling. With each genus in a
family positively determined the difficulties and uncertainties
of others will gradually disappear.

To determine his species the student will need access to a
large number of papers, lists of which to the present time will
be found in the catalogue of Osten Sacken, and on page
XXXIII of the present work. There are a few masters of dip-
terology, and the student will never err in consulting their
writings, no matter upon what subjects they may be. Of
these I would especially mention Meigen, Wiedemann, Win-
nertz, Loew, Schiner, Osten Sacken, Wulp and Brauer. Other
writers whose works are indispensable, but who are not to be
trusted as guides, are Desvoidy, Macquart, Walker, Rondani,
Bigot, etc. Of the contemporary writers whose works will
be found useful, and in most cases valuable, may be mentioned
Austen, Eaton, Meade and Verrall of England ; Bergenstamm,
Kowarz, Mik and Strobl of Austria ; Becker, Girschner, Boeder
and Buebsamen of Germany ; Dziedzicki and Schnabl of Po-
land ; Bezzi and Giglio-Tos of Italy ; Bergroth of Finland ;
Skuse of Australia ; the Lynchs of South America ; Aldrich,
Banks, Coquillett, Johnson, Scudder, Snow, Townsend and
Wheeler of this country. Probably the most useful single
v/ork that the student will find after Osten Sacken's Catalogue
(Smithsonian Ins. lcS78) is Schiner's Fauna Austriaca, and
the most useful foreign periodical the Wiener Entomologische
Zeitung, of which the accomplished Mik is one of the editors.
The Zoological Record will be almost indispensable in ascer-
taining what has been done during the past thirty-six years.
For the beginner I would especially recommend Comstock's
Manual for use in conjunction with this work.



INTRODUCTION. IX

Diptera may always be recognized by the presence of but
One pair of wings ; the second pair of other insects is really
represented by a small organ on eacli side back of the trne
wings, consisting of a short, slender stem with a knob-like ter-
mination, called the halteres or poisers. Their function is
not known ; that they have some function seems certain, as
they are always in vibration during flight. Not all flies are
winged; in some degraded forms, both among the lowest and
highest groups of the order, they may be entirely wanting, as
also the halteres. Sometimes the males will have wings and
the females be wingless. But the number of wingless forms
is very small.

In the adult state the habits of flies are very various. Some,
but not a very large proportion, are predaceous upon other
insects, sucking their juices. Some are very annoying to man
and other warm-blooded animals, sucking their blood ; of these
may be mentioned the mosquitoes, black-flies, horse-flies, sta-
ble and horn flies, the tsetze fly, etc., as well as all the pupipara,
which are parasitic upon birds and mammals. By far the
largest number of diptera, however, feed upon vegetable sub-
stances, either fresh or decaying, the pollen and honey of
flowers, etc. Some feed upon ordure and decaying material
of whatever nature it may be.

In the larval stages, the habits are yet more diverse. Brief
references to the larval habits will be found in the following
pages. Suffice here to say tliat the larger part are vegetable
feeders, but not a few live upon decomposing animal matter,
or in the living bodies of other insects, snails, reptiles, birds,
mammals, etc. While some members of the order may be
very annoying or prejudicial to man's economy, the order,
upon the whole, is a beneficial one, whether in the larval or
mature stages, whether as parasites upon other, and injurious
organism, or as scavengers.

In the following pages I endeavor to give such definitions
and descriptions of the mature insect as will enable the stu-



X INTRODUCTION.

dent to understand and appreciate, not only the present work,
but all other systematic works upon diptera. I have not
thought it desirable to consider at length many interest-
ing subjects connected with them, such as the internal anato-
my, embryology, etc., as being rather apart from the object of
the work, — an introduction or, aid to the study of systematic
dipterology.

HEAD.

The head in diptera is extremely variable in shape, reach-
ing its most remarkable development in the Diopsidse and
Nycteribiidse. It is frequently more or less hemispherical, but
more often the posterior surface or occiput, is flattened or
even concave, giving a more hemispherical form. Often it is
flattened and widened transversely as wide or wider than the
thorax. In the Nycteribiidse it may be folded back into a
groove on the dorsum of the thorax, but with those exceptions,
it is always attached to the thorax by a freely movable neck.
Next to the wings, the head offers the most important char-
acters for classification.

Eyes. The large compound eyes are present in all diptera
save some Pupipara. In the great majority of males they are
contiguous on the upper side of the head for a greater or less
distance; in such cases the insects are called holoptic. In
many males, however, (all the Acalyptratse and several fami-
lies of the Orthorrhapha, as well as in numerous genera of
other families) and in all females with but few exceptions
(some Acroceridse, Blepharoceridse, Bombyliidse and Platype-
zidse, etc.) the eyes are separated more or less broadly by the
front ; such insects are called diclioptic. Earely the eyes may
be contiguous below the antennae or both above and below
them, as in the Acroceridse. In not a few flies, especially
those of the aerial eremochsetous 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 di-
vided. In these flies especially, the eyes in life are often



INTRODUCTION. XI

brilliantly and beautifully colored with green and purple
markings. Sometimes the enlargement of the facets is on the
anterior portion and common to both sexes, as in the Asilidse.
The larger number of flies have the eyes bare, or pubescent
only when seen under high magnification. Very often, how^-
ever, the whole or part of the eyes is covered with erect pile
or hair, which always finds its greatest development in the
male sex. The pilosity may be sparse or dense, short or long.

Ocelli. On the upper part of the head, between the com-
pound eyes there are three simple, small eyes, present in most
diptera, and called the ocelli. They 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 whose apex is in front ; sometimes they are
located in a nearly straight line transversely, or, the middle
one may be absent, and the other two situated one on each
side close to the compound eyes.

AntennoB. No other organs furnish so many or so important
characters in the classification of the diptera as do the anten-
nae or feelers, as the}^ have been sometimes called. The num-
ber, shape, and arrangement of the joints offer, not only
specific and generic characters, but in some cases family char-
acters as well. Only in exceptional cases is the number less
than three, and there may be as many as thirty-six, it is said.
Through all the Cyclorrhapha the number three is constant,
with the exception of the Phoridse, and the Pupipara. In the
Nematocerous Orthorrhapha the number is usually from eight
to sixteen, the first two of which form the scape, and which
are always more or less differentiated from the remainder,
which constitutes the flagellum. Osten Sacken has proposed
to call those flies which have the antennae long and frequently
bearing whorls of hairs, especially in the males, the true
Nematocera, in distinction from the anomalous Nematocera,
in which the antennae are shorter, destitute of whorls of hairs
and with the joints pressed close together. Upon the antennal



XII INTRODUCTION.

character alone, however, the group can not be satisfactorily
separated from the anomalous Brachycera, in which the anten-
nse are more usually three-jointed, with the third joint divided
into segments. Nor can the latter be clearly separated from
the true Brachycera, in which the third joint is not annulated.
Sometimes the third joint appears to resemble that joint in
the true Brachycera, but will be found upon close inspection
to be composed of a number of closely united segments or
annuli, and it is in these cases that the term complex is applied.
This character will be easily understood by examining the
third antennal joint of a common horse-fly. Either the com-
plex or the simple third joint may terminate in a bristle,
usually called an arista, or in a style, that is a more slender
portion, which is, however, not bristle-like. It is very evident
that both the style and the arista represent only the more or
less attenuated distal joints of the flagellum, because in all
cases a close examination will show them to be composed of
from two to five segments. The arista or style is frequently
entirely wanting in the Orthorrhapha, but only rarely is it
atrophied among the Cyclorrhapha. The style is alwaj^s ter-
minal, because it is less differentiated from the flagellum, but
the arista may be either terminal or dorsal, and it may be
inserted close to the base of the third joint. It is also evi-
dent here that the change of position is more apparent than
real, because it is in reality due to the greater development
of the under side of the third joint. In some cases the third
joint has developed into most singular structures, as for ex-
ample in Neochauna and Blastocera among the Stratiomyidse,
or Talarocera, Schizotachina, Dichocera and Diglossocera,
among the Tachinidse-.

Frequently the arista has short hairs growing from its up-
per and lower sides, in which cases it is called pubescent ; when
the hairs are longer and more feather-like, the arista is said
to be plumose ; or, if the hairs are fewer and stronger, pecti-
nated. The plumosity or pectination is always stronger on
the upper side of the arista.



INTRODUCTION. XIII

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 margin
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 when placed on a triangle indicated by grooves or de-
pressions is 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.

Ptilinum. In the Cyclorrhapha an inflatable organ capable
of being thrust out through the frontal suture just above the
root of the antennae, and which is used by the imago in spring-
ing 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.

E'pistoma or Peristoma. The oral margin and an indefinite
space immediately contiguous thereto.

Ant ennal fovea. A groove or grooves in the middle of the
face, as though for the lodgment of the antennae, bounded on
the sides by t\\Q facial ridges.

Cheeks. 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 be-
low the margin of the mouth in front as a more or less visor-
shaped piece.

MOUTH-PARTS.

The mouth-parts of diptera are wholly suctorial. They
differ not a little in the different flies, as might be supposed



XIV INTRODUCTION.

from the diverse habits. In some they are adapted for pierc-
ing animal or vegetable substances and are, in consequence,
firmer and more slender ; in others, and by far the greater
number, they are adapted only for sucking up juices or
such substances as may be dissolved by the aid of the saliva.
Grains of pollen have been observed in the digestive organs
of the Syrphidse and other flower flies, but, as a rule, fluids
only serve as food. Many have the proboscis wholly retrac-
tile 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. Einally a few
species have the mouth-parts rudimentary and take no nour-
ishment in the adult state.

As regards the different parts of which the mouth-organs
are composed, there is a strong contention on the part of Prof.
John B. Smith that the homologies previously and generally
accepted by entomologists are not the correct ones. I have
followed his arguments as carefully and as fully as I am able,
but I will not pretend to assert any authoritative opinion in
the matter, as that would presuppose a thorough acquaintance
with the mouth-structure in other insects than the diptera,
which I do not possess.

The more commonly accepted homologies are as follows :
labium, maxillae, maxillary palpi, mandibles, hypopharynx,
and labrum or labrum-epipharynx. The labial palpi are
thought to be wholly wanting, 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 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 maxillae and mandibles are sometimes absent, the mandi-



INTRODUCTION. XV

bles 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 com-


1 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Online LibrarySamuel Wendell WillistonManual of the families and genera of North American Diptera → online text (page 1 of 18)