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The Families and Genera
of
North American Diptera
By C. H. CURRAN, D. Sc,
American JMuscum of Natural History,
New York, N. Y.
C. H. CURRAN
1934
Copyright, 1934, by C. H. Cup.itAN.
Printed in the United States of America by
The Ballou Press,
New York, N. Y.
1934.
CONTENTS
PAGE
Frontispiece. Portrait of Dr. S. W. Williston.
Preface 7
Acknowledgements 9
Collection and Care of Diptera 10
Flies and Disease 12
Flies and Crops 13
Beneficial Flies 14
Anent the Insect War 14
Morphology of Diptera 15
Classification of Diptera 16
How to Use the Keys 20
Table of Families 21
Characteristics of Families and Keys to Genera 28 to 479
Glossary of Terms Used in Dipterology 480
Literature 494
Index 496
Errata
p. 22. add the following:, line:
Wings rounded at the ai)ex, almost always with crossveins 31.
p. 76. Tsoecacta Garrett = AUuaudoviyia, and not Dnsyhclea.
p. 82. third line, for Amopheles read Anopheles and for Algj/pti read cegypfi.
p. 274. for '*29" in middle of page read 24.
pp. 286, 288, 290, 292, 294 and 295. for Trypaneida read TrupaneidsE.
p. 405. second line, for Saerophaga read Sarcophaga.
Preface
Twenty-five years ago Williston's ^lanual of North American Diptera (third edition), was offered to the public and in the interim it has held the esteem of students of Dipterology in every quarter of the globe. Williston's first synopses of families and genera appeared in 1884 and following years in the Bulletin of the Brooklyn Entomo- logical Society and in 1S88 the first edition of the ''Manual" appeared. This "pamphlet", as it was modestly termed by its author, contained 88 pages, excluding as it did, the Nematocera and Muscoidea. The second edition appeared in 1896, and included the Nematocera but omitted the Tachinidaj and Dexiida^. The third edition contained all the families, fifty-eight in number.
The present attempt at a classification of the genera of North American Diptera is the result of many years of study but it is incon- ceivable that this work should be uninfluenced by such a masterpiece as that of Williston. That a new synopsis is urgently needed Ijecomes obvious when one considers the enormous number of new genera de- scribed since the appearance of Williston's Manual, the realignment of genera, the application of newly discovered characters and the increased importance of the study of flies in relation to human welfare.
Knowing, as I do, the excellent quality of Dr. Williston's work it is with temerity that I offer this contribution to a critical public. Even though great pains have been taken in its preparation and every effort has been made to make the keys as complete and simple as possible I fear that some few errors have crept in. That is inevitable. Where they occur I do not know, nor do I offer excuses for them other than to admit an utter ignorance in regard to the characters of thousands upon thousands of Diptera, even though I have had available for study the excellent collections of the Smithsonian Institution, Canadian National Collection and the American Museum of Natural History and the gen- erous assistance of various specialists. If mention is not made of those who have contributed to this work, either wittingly or unwittingly (through their synoptic revisions), it is only because the body of the paper has increased to such proportions that a complete acknowledg- ment must be omitted.
A few innovations will be found. Where reasonably complete spe- cific keys occur these are referred to in footnotes and the same is true in' the case of family revisions. The synonymy has increased so greatly that some indication of it must be given, especially where old familiar names have been changed; this is indicated in the index and while it is far from complete it is hoped that some help may be derived from such an arrangement.
e NORTH AMERICAN DIPTERA
It is my hope that those who may discover errors or omissions may be kind enough to call them to my attention, indicating the manner in which the corrections may be made. Owing to the numerous footnotes it has not been possible to indicate the genera which have been included from description only. Such genera naturally weaken a key as it is impossible to use characters which may be available for a more suitable arrangement. Any specimens representing genera improperly placed, or not common, would be most greatly valued by the author.
Finally I wish to express my unbounded admiration for the late Samuel Wendell Williston. To him I owe, as do very many others, an everlasting gratitude for his kindly encouragement, while he lived, and real inspiration from his printed works. I know of no Dipterologist who has so clearly set forth the facts or who has been so great an inspiration to others. And as a slight token of my appreciation I re- spectfully dedicate this book to his memory.
C. H. CURRAN,
American Museum of Natural History, New York City, 1933.
Introduction
Acknowledgments
It is impossible to express fully my appreciation of the generous cooperation of all those who have assisted in the preparation of this Avork. It is most fitting that I should mention first the generosity of Mrs. S. W. Williston for not only permitting me to use the illustrations from Williston 's "Manual of North American Diptera", but for her offer to furnish the cuts themselves. Needless to say this offer was ac- cepted and many of the illustrations are reproduced from cuts used in the ]\Ianual. Unfortunately, due to a rearrangement of many genera and their transfer to different families, it has not been possible to use all of the cuts. Further, in this connection, I owe much to ]\Irs. George Shor, a daughter of Dr. and Mrs. Williston, for her assistance in this matter, and for her sympathy in the work. It might not be out of place to mention here that, according to Mrs. Shor, her father, upon the com- pletion of the manuscript of the third edition of his Manual, dropped it upon his desk and remarked: "Well, that's finished. When it is re- vised again, it will be by someone else. ' '
Every request for the loan of specimens and for the review of keys met with a wholehearted response and as a result the value of this book has been greatly enhanced. Dr. C. P. Alexander is deserving of especial thanks for the preparation of the manuscript dealing with the Tipuloidea and the preparation of the illustrations for that superfamily. Drs. Jos. Bequaert, C. T. Brues, 0. A. Johannscn, Roljert IMatheson, F. ]\I. Root and ]\Ir. IMarston Bates liave assisted very materially in clieck- ing over keys and suggesting changes. Dr. E. P. Felt suggested the use of illustrations from his papers published in the Bulletins of the New York State Museum on the Ceeidomyid» (Itonidida^) and Dr. C. C. Adams very generouslj^ furnished the cuts. Drs. J. M. Aldrich, F. H. Benjamin and Mr. Marston Bates, and others have loaned specimens not found in the American I\Iuseum collection and Dr. ]\Iatheson has given permission to use illustrations from his "Handbook of the Mosquitoes". I wish also to express my a])preciation to all those Dipterologists of the past and present whose works have been so freely drawn upon.
The preparation of a work of this kind entails a large amount of stenographic and routine work and for the careful typing of the manu- script I am indebted to ]\Iiss Ethel Olsen. j\Ir. Adolph Klein has con- tributed the excellent colored plate of several typical forms, while my wife has assisted with the illustrations and in many other ways.
10 NORTH AMERICAN DIPTERA
For the encouragement he has given during the preparation of the manuscript I shall always feel a deep sense of gratitude to Dr. Frank E. Lutz. The American Museum of Natural History is deserving of particular mention, since the work has been done in this institution without any limitations as to time devoted to it.
If the book should be found useful and helpful, full credit should be given to the ]\Iuseum as well as to all those who have so generously given of their time and knowledge.
Collection and Care of Diptera
So much has been written about the ease with which collections of insects may be cared for that I feel a word of warning to be not amiss. It is true the Lepidoptera and Odonata may be "papered", Hymenop- tera, Hemiptera and CoIeoiJtera may be packed between layers of cotton and Coleoptera may be collected in alcohol but most of the other Orders require more care. With the exception of Coleoptera and the small insects normally collected in alcohol and intended for study in this liquid, or for slide preparation, all insects are much better pinned while fresh. Packing Diptera between layers of cotton may result in recog- nizable si^ecimens and a small percentage of really good specimens may be secured but the majority can never be made to look attractive.
With small flies pinning should take place within four or five hours of the time of capture and all specimens should be mounted within eight hours. In cold or damp weather a greater time may be allowed to elapse and the time should be shortened in hot, dry weather.
Mounting Diptera should not be a slip-shod process and care should be taken to have the flies an even height on the pins. An excellent prac- tice is to have the mesonotum about one-third the distance from the top of the pin. This i)ermits of careful handling of the specimen and re- duces danger of damage to a minimum. Many Entomologists pin Diptera less than a fourth the distance from the head of the pin with the result that the specimens are quickly damaged and ultimately cease to have value. Double mounts should never be used for Diptera. If a specim'ni is too small to be pinned through the thorax it should be fastened to the side of the i)in by first circling it (the pin) with a narrow ring of white shellac and touching it to the side of the insect. In this way the specimen may be handled in the usual manner and all parts may be readily seen. If possible, the wings should be arranged so that they extend over the back of the insect in an upright position. Pins of suit-
COLLECTION AND CARE OF DIPTERA 11
able size should be used and it will be found that good, steel No. 00 pins may be used for quite small insects for pinning through the thorax. Some collectors seem to have a craze for double mounts, not realizing that the value of their collection is greatly lessened due to the increased risk during shipping and many of them place the accessory mount much loo Iiigh on the ])in. Another practice, that of placing specimens (nicely spread, it is true) on a circular or oval mount of cardboard by use of minute pins, is to be condemned as the characters available on the under side of the specimen are concealed.
LaheUing is an important detail and insufficiently labelled specimens are of little more value than none at all. The fact that a proud collector knows exactly when and where he captured a certain prize is of no value to the student who must needs study the specimen in the absence of the collector. Every si)ecimen should be labelled with the locality, date and name of the collector. Labels should be small and neat and should be I)laced on the pin along the long axis of the insect, the locality on the right hand side. Labels should never be placed crosswise as they are liable to damage adjacent specimens when the insect is being removed for examination. One guide to labelling all insects is to remember that the label should afford protection to the specimen and not be so large that the collection looks like a collection of locality labels rather than one of insects. The labels should be printed, either by machine or by hand and the month should always be in Roman numerals.
In various places in the following pages will be found instructions for the care of those flies which require special attention. No doubt there are many people who will neglect to read the instructions here but to tliose who do I offer a few pertinent hints. Never place Diptera in vials or bottles with other insects. Never cram a vial full of flies. Shake them loose occasionally so that the wings will not become folded. Never place small flies in a vial with large ones and be careful not to place more than a few specimens of flies which rub easily in a vial. Always K'eep mating pairs together ; a good plan is to have a vial for this purpose and to put only different species in it.
Collecting outfits need not be elaborate. I usually carry six to eight test tubes and a bottle about an inch across and four inches long. If the collecting is to be general a bottle Iavo inches across may be carried. Such an outfit will suffice for a half day of very good collecting and if the trip be an all-day one the catch may be transferred to a box and stored in a cool place. Enijity match boxes are convenient receptacles for the transference of fragile specimens and pairs.
The making of the bottle is a simple affair. Oct .some fine sawdust, place in the vial or bottle a small amount of sodium or potassium cyanide
12 NORTH AMERICAN DIPTERA
and add about half an inch of sawdust; wedge this in with a ball of cotton, place in the sun for half an hour and the bottle is ready for use. The cyanide should be broken into small lumps but need not be particu- larly fine. It must be remembered that c\janide is a deadly -poison and extreme care is necessary in handling it. Do not use it unless you arc properly instructed, and if you do, be sure to destroy by burning or burying all paper, pieces of wood, etc., which the cyanide might have touched and wash thoroughly in running tap water hammers, etc. used in crushing the material, as well as your hands. Never handle cyanide if there is an open sore upon the hands. A little extra care may be worth a lot. It might not be amiss to note here that the most efficient antidote for cyanide poison is the intra-venous injection of methelyne blue, one of the best known aniline dyes.
Flies and Disease
As agents in the spread of diseases of mammals the Diptera un- doubtedly rank first in importance among the insects. The chief carriers of diseases are, of course, the biting flies belonging to the families Psy- chodidae, Simuliida, Culicidae, Tabanidai, Glossinidae, Ceratopogonidge and Muscidae. Species of Flehotomus carry papataci fever, verruga or Oroya fever, kala-azar and oriental sore. Other names are applied to these diseases. The mosquitoes carry blackwater fever, yellow fever, dengue, filariasis and malaria. Onchocerciasis is carried by species of Eusi'imdium. A form of filariasis is believed to be carried by a species of Culicoides and species of Chrysops are known to transmit the disease. Tularemia, anthrax and trypanosomiasis are other diseases transmitted by Tabanids. The stable-fly, Stomoxys calcitrans, is known to carry a number of species of trypanosomes and may also be responsible for the spread of poliomyelitis (infantile paralysis), although no definite proof has been obtained. Sleeping sickness is carried by the Tse-tse flies.
In addition to carrying diseases the biting flies themselves cause a great deal of irritation by their bites, especially in the vicinity of water. Life is often made miserable in northern regions by tlie hordes of mosquitoes and black fiJes while the sportsman is plagued by almost all the biting forms while in the woods and bathers come in for much undesired attention from no-see-unis, mosquitoes and Tabanids, par- ticularly the so-called "green-heads", along the coastal regions.
The house fly carries on its body the germs causing typlioid fever, dysentery, cholera, anthrax and conjunctivitis, while a few other flies carry other diseases. Considerable has been written about myiasis caused by the larvae of flies living in the human body. If we except the
FLIES AND DISEASE 13
bot-flies, I think tliat \vc may regard the occiirrence of fly larvtu in the body of man as entirely accidental and dismiss the matter as being a subject of academic interest rather than one calling for serious con- sideration. Tliere are, of course, the bot-flies, belonging to three dis- tinct families and they are serious pests. In the tropics one si)ccieR commonly attacks man, but the greatest damage is done to domestic animals. Hides are frequently so greatly riddled with "warble" holes as to be almost valueless.
The bird and bat parasites, as well as the so-called bee-louse {BrauJa caeca), are probably not serious pests although the sheep tick, belonging to the Hippoboscidaj, is often sufficiently numerous to cause serious damage and some species of Hippohosca bite humans in addition to their attacks on horses, camels, etc.
In many places the so-called blow-flies cause serious loss to sheep owners by "blowing" the wool.
I have given just a very brief summary of some of the injury caused by flies to animal life, as it affects human welfare, and a very great deal that is of interest has been omitted. One frequently re- ceives inquiries as to the diseases carried by flies, and these few para- graphs may serve to answer the questions. In the following pages, under the families mentioned, additional information is given, particu- larly concerning diseases carried by flies in North America. If the student desires further information on this important subject he should secure a copy of one of the better books on IMedical Entomology.
Flies and Crops
It is impossible to enumerate all the flies attacking field, horti- cultural and garden crops, but mention might be made of the various root maggots, the leaf miners, gall makers, fruit flies, grass stem flies and the Hessian fly. The amount of damage done by the groups of insects mentioned must be enormous but it must be remembered that there can be no actual measure of crop damage from a financial ])oint of view. A large crop invariably means lower prices and a small crop higher prices. It is only when individuals or limited communities suffer serious loss in the volume of their produce that there is any real loss, and then it is of a local nature and not national for the producers of the crop affected. It so happens in such cases that one man's loss proves to be another man's gain. While flies undoubtedly do a great deal of damage to our crops and flowers, they are of less importance in this respect than some of the other orders of insects and the Dipt, are, in actual fact, much more beneficial than injurious.
14 NORTH AMERICAN DIPTERA
Beneficial Flies
No group of insects, except, perhaps, the Hymenoptera, are so important to mankind as are the flies. In these two groups are man's best friends among the insects. It woukl be useless to argue about the relative merits of the two orders because we know so little about them that no one is in a position to make any authoritative statement. It is sufficient to say that flies play an extremely important part in the pollination of flowers, but they undoubtedly occupy second position to the bees. It is in the field of predaceous and parasitic members thai these two groups render the greatest service to mankind. If the world should suddenly find itself without flies and bees it would quickly revert to a sphere lacking animal and plant life, so important are these insects in maintaining the "balance of nature".
I believe that the majority of flies, in relation to the number of known species, are either predaceous or parasitic on other insects. Such large families as the Asilida, Empidee and Dolichopida are all pre- daceous in the adult and probably in the larval stage, while the Bomby- liidi^, Nemestrinidse, Conopidaj and Tachinid^e are insect parasites. Other families or groups can be added to the list and we might also include forms which are predaceous in the larval stage. More about the habits of flies will be found in the following pages.
Flies are also beneficial as scavengers and examples of their effec- tiveness may be found everywhere. They dispose of carcasses, decaying vegetation and waste animal products and in this way do much to keep the air pure and wholesome.
Anent the Insect War
I am aware that there has been some sensational propaganda about "the war against insects" and I cannot forego a few remarks. Insects are our best friends and we owe a great deal to them. They are also our worst enemies but this fact should not be proclaimed from the housetops without at the same time crying much louder of the benefits they give us — flowers, fruits, vegetable, clothes, food, pure air, beauty. The stressing of the danger of the "insect menace" may do entomology a great deal of harm and I think it has already done some. It has taught people to dislike all insects and the fact that the "menace" has not developed perceptably has resulted in some loss of faith in entomologists.
The Diptera contain some of our worst enemies. The public should be made aware of this and steps taken to eliminate the pests in so far as possible. Every effort must be made to keep people suft'ering from
ANENT THE INSECT WAR 15
insect-carried diseases out of the country, if such diseases do not occur here and if there are any known carriers of the disease among our insect population. Yellow fever is an excellent example. We have the yellow fever mosquito and if persons suffering from this disease should enter any part of the country where the mosquito occurs the disease might well become established. Every effort should be made to reduce the numbers of the house-fly, stable-fly, and other pests. On the other hand the introduction of parasites, particularly of imported pests, should be encouraged and people should learn to differentiate at least the more beneficial of their insect friends.
Morphology of Diptera
It is not my intention to go into detail concerning the structure or morphology of flies since I have appended a glossary of terms used in this and other works. However, a few remarks on the subject may not l)e amiss. In Williston's manual a simple system of nomenclature is used and I follow the same system. During recent years attempts have been made to homologize the parts of the various orders of insects and as a result many long and unfamiliar terms have been proposed. To my mind the homologies of the parts are much less important to the systematist than a simple, easily followed and long used termin- ology. Nevertheless it is important to know the origin of the various parts, especially so to a zoologist, if he deigns to study that group wliieli comprises three-fourths of the animal kingdom. In each order of in- sects a simple terminology has long been in use and such terms should he employed because the average student can understand them without difficulty. After all, some one has said that "Nature is an open book, and you have but to study nature to understand." Perhaps those are not the exact words, but they will do.
The determination of genera is based upon structure and it is therefore necessary to be acquainted with these parts. The average student will find no difficulty on this score if he will follow the simple expedient of using the keys and consulting the glossary. In this way the terms used will soon be mastered and the student will find little difficulty in tracing out specimens.
The student who desires to delve into the anatomy of Dipter;' should obtain a bibliography of the works on this subject, particularly those by Crampton and Snodgrass. ]Many references will be found in Imms' "Recent Advances in Entomology" and "Biological Abstracts"
It will be found that autliorities differ as to the origin and homol- ogy of different organs. A comparison of the Oomstock-Needham sys- tem as used by Dr. Alexander in this work and that of Comstock will
16 NORTH AMERICAN DIPTERA
show certain differences while others disaoree in the terminology as applied to the veins in other families of Diptera as well as in other orders of Insects. It must be pointed out that the Comstoek-Needham terminology of wing venation is very widely used, probably by more students of Diptera than any other system, and if American students desire to study exotic flies they must familiarize themselves with this system as well as the system used by many Europeans. Explanations of these systems will be found in the glossary.
Classification of Diptera
The classification of any .grou]) of animals is a complex problem having its basis in the morphology, histology, embryology and general biology of the phylum, and without a knowledge of these "ologies" no satisfactory classification can be obtained. In addition we must also turn our attention to paleontology, although it must be confessed that very little is known concerning the Diptera of the past ages. In the present work we deal almost entirely with morphology of the adult flies, not from any desire to ignore the other phases of study, nor from any lack of interest in them, but because our space is so limited and each field is so vast that a lifetime of study would leave any field almost untouched. The truth is that we know practically nothing about the biology of flies although we may say, in a general way, that we are acquainted with their mass biology and that we can usually place a species biologically by associating it with some related form.
The taxonomist, however, is forced to deal with adult structures, to classify thf creatures by characters he may select and to leave to some one else the pleasure of working out the biology of the insects studied. If you are at heart a taxonomist and are informed that you know nothing of ])iology unless you study life histories, do not be dis couraged. Instead, feel rather strongly inclined to turn a deaf ear to your adviser, taking solace in the fact that even though you may spend all your available time at the systematic study of the adult insects, and gleaning what you may from the writings of others on biology and life history studies, you will never be able to fully master the field you have chosen. There are so many flies that no one can ever truly profess to know them all and their very numbers preclude a thorough survey of the orcTer tending to a complete classification.
It is well, and necessary, to warn against too great specialization, and at the same time it is realized that many students with limited time are unable to study more than one or two families. The great trouble with the intensive specialist is that he loses his sense of proportion and relatively minor details are liable to assume the greatest importance in
CLASSIFICATION OF DIPTERA 17
his mind. In order to overcome this intra-specialization the student should enlarge his outlook by collecting in other families and also in other orders, even though no time be available for a study of his com- plete catch. The collector who studies a single family may produce a monumental work providing he is painstaking and accurate while the general worker is less liable to accomplish lasting results.
I hope I may be excused if I wander a little aside from a technical discussion of classification to discuss lighter but equally important mat- ters. The real object of this work is not the classification of the Diptera but the presentation of keys to enable the student to place his specimen in the proper genus — or, in short, the generic identification of flies. Nevertheless, we must glance below the generic classification and find out something about species, and it is about the description of species of which I wish to say a few words hei'c.
There is nothing more ])leasing than a good description and nothing more aggravating than a ]ioor one. All of us, in our ignorance, may offer poor descriptions at times but we should always strive to make them clear and concise. We should try to step beyond ourselves and look at the description from the viewpoint of another student. If two animals are different, in our estimation, we should clearly express the differences, laying special stress upon tlie outstanding characters. A description should not be too long, nor sliould it be brief and stilted. I can do no better than recommend that every Dipterist read the descriptions contained in Williston's ''Synopsis of North American Syrphidti?" and pattern descriptions after those. The elimination of words and the excessive use of abbreviations is scarcely to be con- doned, even on the ground that it is "scientific". If "science" is to ])e measured liy a stilted language and a lack of consideration for others, it deserves little consideration from humanity as a whole and we should divorce "science" and study insects just for the fun of the thing.
Today tlie student need not worry a great deal about some one ''stealing his thunder". ]\Iost eminent entomologists are only too glad to ])e of assistance to the young student and to leave to him the descrip- tion of new species. This does not mean that the specialist is willing to name large collections and return all the material. If he were he would be so swamped witli work that he would have no time for his other duties. ^lost specialists name material on the understanding that they may retain what they wish, and as a rule they desire very little. The beginner sliould 1)e only too glad to assist the specialist by filling in gaps in his collection, because every species added makes his work that much easier in future. It must also be remembered that many special- ists are employed by institutions having large collections of unworked
18 NORTH AMERICAN DIPTERA
material and that every collection named means less time for institu- tional work and, to make a blunt statement, it is only fair to expect the institution to look for some return from the labor of its employees. However, I do not know of anyone who is not happy to verify a student's findings and to give opinions and suggestions concerning the distinctness of specimens, and, of course, in such cases they are re- turned if desired.
I cannot condemn too strongly the professor who permits a student to work on a systematic or biological paper and to allow or even urge that the results be published unless the material has been examined by a specialist, or the species of which the biology is being studied has been identified by one in authority. Each year many students are given such problems and the results are frequently very unsatisfactory. Too much care can not be exercised in the preparation of scientific descrip- tions of either genera or species and it should be realized that a good collection must be available before any work can be faithfully under- taken.
The preparation of keys is a very imi)ortant matter and their in- corporation in a contribution adds greatly to its value. Some authors attempt, in their keys, to portray what they term a ''natural classifica- tion ' ', but it should be borne in mind that this is impossible. We know too little about the insects with which we are dealing to produce any such result. In preparing keys we arbitrarily accept one or more characters for the separation of groups and, if the key is to be useful, the characters used for each se])aration must be clean-cut. In any large group it will be found to be very difficult to find clean-cut char- acters in every case, some forms apparently going into either group although the character used may serve for the vast majority. In cases of this kind the doubtful forms should be run through both categories. In the so-called "natural" grouping it is very frequently necessary to employ characters which are not conspicuous and such keys are liable to prove very difficult to use. Characters expressing a degree of varia- tion sliould be avoided wherever possible, i. e. front produced vs. frcMit less produced. These characters may be obvious to the maker of a key but are certainly not recognizable to other students whose collections may be limited. It is usually easy to use a key if you know most of the forms but often difficult or impossible otherwise.
All keys should be dichotomous and the use of more than two alternatives should always be avoided. In a short key one may use the "a" and "aa" system but it is not to be recommended in any case. Keys so constructed are more time consuming than such as are used in the present work. In the present case an attempt has been made to
CLASSIFICATION OF DIPTKRA 19
produce simple keys, amply illustrated. It must be remembered, how- ever, that the illustrations will not serve for all si)eeies in a genus but represent, as a rule, typical forms.
No use has been made, in general, of subfamilies or subgenera. The use of such almost always calls for many exceptions and also un- necessarily encumbers the literature. A sub-family is supposedly a distinct entity within a family, a group separable upon certain char- acters, but that such classification is unnecessary is evidenced by the exceptions. As an example — the Tachinidse have been divided into many sub-families, or even families, upon such characters as the absence of abdominal bristles, shape of head, etc., etc., but there is not a single character, nor for that matter group of characters, upon w^hich any of these groupings may be retained. Many of the characters in this family are excellent up to a certain point, but every character falls down, not once, but in many instances throughout the family. It is entirely im- possible to separate the Tachinida? and Dcxiidff, just as it is to separate the Muscidffi, Anthomyida? and Scatophagida?.
Subgenera are superfluous. They are proposed as a rule because the author hopes that some day some character may be found upon which a distinct genus may be based. It is well to remember that in nature there is no such thing as a subgenus, genus or family. Their use is a human creation made possible because links connecting the groups have either entirely disappeared or have not been discovered by man. Genera are therefore artificial and the answer to the question of ''what is a genus?" is that it is something limited in some way by some one. This may sound facetious but it is not meant to be so. The trutli is that certain arbitrary characters have been set up, all the species falling within the limits set forth constituting a genus (or a species or family). It is presumed, but by no means certain that connecting links do not exist.
Many people describe sub-species, varieties, races, forms, etc., espe- cially in the Lepidoptera, but, fortunately, the fad has not become ex- tensive in Dipterology and it is to be hoped that it may never do so. In actual fact there is no difference in a sub-species, race or variety. A variety is something which differs from the typical or first described form in some definite way. Thoy are explained as potential species, ignoring the fact that no two specimens are exactly alike and that if two extremes of similar type should mate a new race would be formed. In each batch of eggs there are produced forms possessing characters some- what different from the par(-nts. But the species does not change be- cause the average is maintained by the resultant mating. It is only when forms become more or less isolated that a definite trend occurs and
20 NORTH AMERICAN DIPTERA
so-called races (supposedly geographie forms) are developed. In such cases connecting or transition forms usually occur and it is almost always true that the races, say northern and southern, are connected in the intervening region by a perfect transition of the characters of the two races. Races are interesting but it is not necessary to give them names. Moreover, "variety" was used in the same sense long before people thought of "races" for biological classification and 1 think we may extend the law of priority and use it in this sense, thus eliminating "race" and "sub-species".
The naming of aberrations, transition forms and sucli things should be beyond the pale in true science and such a practice must eventually result in ridicule of the science as a whole. It is, of course, verj^ neces- sary to call attention to tliese forms but to name them is utterly needless. Knowledge of them is essential in tracing out the relation- ship and development of species, and of great interest, too, but we should not lose our perspective and attach exaggerated importance to names.
How to Use the Keys
The use of keys is not a difficult matter l)ut there may be some who have not had experience with them. Some keys may not be altogether simple and may not run as smoothly as others. To find the genus to which your specimen belongs turn to the table of families (on the following page) and read over couplet 1. Two alternatives are given: the insect must go in either section. If it has large wings you go to couplet 2 and you repeat the process until it is found that your s])eci- men comes to a section where it agrees with the diagnosis ending in a family name. You have now found the "family", but to be sure read over the other alternative so that the characters in both may be checked. Now turn to the family indicated and continue in the same way until tlie genus is reached.
It sliould be remembered that keys are merely guides and the fact that a species traces out to a certain ])lace in a key is no guarantee that it actually belongs there. If one is familiar with the genera of a family he may be reasonably certain either that tlie insect belongs where it traces or that it is quite different; in either case he should check with descriptions of genera not included in the key or with the genus in- cluded, either by means of determined specimens or with the generic description. If a specimen does not seem to agree with the genus to which it traces check back and try one of the other alternatives since there may have been an error in interpretation of the characters used or the specimen may be one that is somewhat aberrant.
Sphecomyia rituitn Wied. (Syrphidae)
Aloipha cingulata Schlner. (Stratiomyidae)
Dejeania reiatrix O. S. (Tachinid;e)
Hijperalnnia hela ICriclis (Bombyliidae)
Mijdns clnrnlus Fabr. (Mydaidae)
Tabanitx rinctiis: Drury. (Tabanid.-e)
Richardia teJesropica Gerst. (Otitida>)
M ichogasler niger Schm. (Otitidae)
Diden fuscipes Macq. (Syrphidre)
21 TABLE OF FAMILIES
1. Wing-s absent or greatly reduced 91
Wings present, rarely reduced 2
2. Antennae composed of six or more freely articulated segments 3
Antenna composed of not more than five freely articulated segments,
the third segment sometimes complex, usually bearing a style or arista 22
3. Mesonotum with an entire V-shaped suture 4
Mesonotal suture transverse, not V-shaped 7
4. Ocelli absent 5
Ocelli present (p. 31) TRICHOCERID^.
5. Only one anal vein reaches the wing margin 6
Two anal veins reach the wing margin (p. 33) TIPULID^
6. Second and third veins each with two branches (radius 5-branched)
(TipulidEe plate II, fig. 11) (p. 29) TANYDERID^
Second and third veins with only three branches reaching the wing margin (radius 4-branched) (Tipulidae plate II, fig. 12) (p. 30).
PTYCHOPTERID.^
7. Wings without a network of folds or creases 8
Wings with a network of fine folds or creases (p. 61) BLEPHARICERID^
8. Ocelli present 9
Ocelli absent 14
9. Costa continuing around the wing, although weakened behind.
(p. 101) CECIDOMYID^ Costa ending at or near the wing-tip 10
10. Discal cell present 21
Discal cell absent 11
11. Tibiae with apical spurs 12
Tibiae without apical spurs, though produced spur-like.
(p. 131) SCATOPSID^
12. Eyes more or less connected by a projection above the base of the
antennse (p. 118) SCIARID^:
Eyes separated 13
13. Antennae placed below the compound eyes, usually close to the oral
margin " "(p. 128) BIBIONIDiE
Antennae situated at most slightly below the middle of the compound eyes (p. 120) .MYCETOPHILIDiE
14. Costa continued around the margin of the wings, though weaker behind
the apex 17
Costa ending at or near the apex of the wing 15
15. Wings very broad, the posterior veins weak and poorly developed.
(p. 63) SIMULIID^ Wings narrow and long, the posterior veins stronger 16
22 NORTH AMERICAN DIPTERA
16. Wings lying flat over the back when at rest; metanotum short and
without a longitudinal groove; femora sometimes swollen.
(p. 74) CERATOPOGONID^ Wings lying roof-like over the back when at rest; metanotum long and with a median longitudinal groove; legs long and slender.
(p. 69) CHIRONOMID^
17. Wings short and broad, folded roof-like over the body when at rest,
usually pointed (p. 78) PSYCHODID^
Wings long, or if broad, the apex very broadly rounded, always lying flat over the back when at rest IS
18. Venation very much reduced, several of the veins lacking.
(p. 101) CECIDOMYID.^ Venation not reduced, the veins strong 19
19. Basal cells long, extending to or beyond the middle of the wing 20
Basal cells, especially the second, short, not extending nearly to the
middle of the wings (p. 67) THAUMALEID^
20. Apical veins strongly arched (p. 80) DIXID^
Veins straight or nearly so (p. 83) CULICID^
21. Fourth posterior cell widely open (p. 59) ANISOPODID^
Fourth posterior cell closed (p. 133) RACHICERIDifc]
22. Empodium developed pulvilliform, the three pads nearly equal 23
Empodium hair-like or absent 29
23. Third antennal segment compound, composed of annuli 24
Third antennal segment simple, usually beai'ing an elongated style or
arista 27
24. Squamae large and conspicuous (p. 148) TABANIDiS^
Squamae small or vestigial 25
25. At least the middle tibiae with spurs (p. 146) CCENOMYID^
Tibial spurs absent 26
26. Posterior branch of the third vein ending before the wing-tip.
(p. 134) STRATIOMYID^ Posterior branch of the third vein ending well behind the wing-tip.
(p. 155) PANTOPHTHALMID^
27. Squamae very large; head very small, placed low down, composed almost
entirely of the eves, the face and front very narrow or obliterated.
(p. 203) CYRTIDZE Squamae small; head larger, the face or front broad 28
28. Middle tibiae with spurs; venation not complex. . . (p. 157) RHAGIONID^ Tibiae without spurs; venation intricate, many veins ending before the
wing-tip (p- 201) NEMESTRINID^
29. Wings rounded apically, with strong veins antei'iorly and very weak,
oblique ones; coxae not widely separated by the sternum.
(p. 234) PHORID^ Wings with normal venation or pointed at the apex, or the coxae broadly separated by the sternum 30
30. Wings pointed at the apex, without crossveins.
... 0 t f^ (P- 2^2) LONCHOPTERID^
TABLE OF FAISIILIES 23
31. Two or more submarginal cells, the third vein furcate 32
Only one submarginal cell, the third vein simple 38
32. Front hollowed between the eyes, strongly concave from anterior view.. 33 Front scarcely or not at all concave from anterior view 34
33. At most one ocellus; at most two veins reach the wing margin behind
the apex (p. 163) MYDAID^
Three ocelli; at least four veins reach the wing margin, or extend to- ward it, behind the apex (p. 167) ASILID^
34. Costa continuing around the wing; fourth vein ending beyond the wing-
tip 35
Costa not continued beyond the apex of the wing; fourth vein ending before the wing-tip (p. 161) SCENOPINID^
35. Five posterior cells 36
At most four posterior cells 37
36. Fourth vein ending before the apex of the wing. .(p. 189) APIOCERIDiE Fourth vein ending behind the apex of the wing. . . (p. 185) THEREVID^
37. Anal cell open or closed near the wing margin, the anal vein reaching
the margin (p. 191) BOMBYLIID^
Anal cell closed far from the wing margin, the anal vein never extend- ing to the margin, sometimes absent (p. 205) EMPIDi35
38. Anal cell elongate, tapering and acute apically, closed near the border
of the wing; basal cells usually elongate 39
Anal cell short, transverse, oblique, or convex apically, if somewhat pointed the apex partly transverse, partly di"awn ovit into a triangular point posteriorly 40
39. Anal cell closed very close to the wing margin; a spurious vein running
obliquely between the third and fourth longitudinal veins.
(p. 247) SYRPHIDJE Anal cell usually shorter; no spurious vein 40
40. Head extremelv large, hemispherical, the front and face very narrow;
arista dorsal' (p. 245) PIPUNCULID^
Head not unusually large; face or front usually wide 41
41. Frontal lunule entirely absent, the parafacials not differentiated by a
suture 42
Frontal lunule present; parafacials differentiated by a suture which ex- tends above the antennae and is indistinct only in some Conopidse. . . .44
42. Anterior crossvein situated at or before the basal fourth of the wing;
second basal and discal cells always united... (p. 215) DOLICHOPID/E Anterior crossvein situated far beyond the basal fourth of the wing or the second basal cell complete 43
43. Anal cell pointed posteriorly; proboscis never rigid and adapted for
piercing ' (p. 242) PLATYPEZID^
Anal cell not pointed posteriorly; proboscis usually rigid; never a single row of acrostical hairs (p. 205) ExMPID^
44. Cox£e close together at the base, the legs attached ventrally 45
Coxas widely separated at the base, the legs attached toward the sides
of the thorax; usually leathery or coriaceous flies; ectoparasites (Pupipara) 91
24 NORTH AMERICAN DIPTERA
45. Second antennal segment with a longitudinal seam along the upper
outer edge extending almost the whole length; posterior calli defi- nitely formed by a depression extending from behind the base of the wings to above the base of the scutellum (Calypteratse; Muscoidea) . .85 Second antennal segment rarely with a well developed dorsal seam, the posterior calli not differentiated (except in Gasterophilus) ; squamae small (Acalypteratse) 46
46. Mouth parts vestigial, sunken in a very small oral pit.
(p. 400) GASTEROPHILID^ Mouth parts well developed, the oral opening large 47
47. Posterior spiracle with several hairs on the border in addition to the
pubescence, (visible only with high magnification) 50
Posterior spiracle with pubescence only 48
48. Subcosta complete, free from the first vein and ending in the costa
( cf . Trypaneidae ) 64
Subcosta incomplete, or not ending in the costa or the apex curved forward beyond the bend 49
49. Subcosta curved forward at nearly a right angle and weakened beyond
the bend, the costa fractured at the apex of the subcosta; wings
almost always pictured (p. 285) TRUPANEID^
Subcosta not angularly curved and weakened 51
50. Head broad, flattened above; scutellum and thorax flattened, the former
elongate; large flies (p. 299) ROPALOMERIDJE
Head rather spherical; scutellum usually convex, not elongate; small, cylindrical flies (p. 313) SEPSID^
51. First segment of the posterior tarsi shortened and incrassate.
(p. 360) BORBORID^ First segment of the posterior tarsi normal, usually longer than the second 52
52. Anal cell absent 53
Anal cell present 55
53. Postocellar bristles divergent (345) EPHYDRID^
Postocellars convergent or absent 54
54. Ocellar triangle large; fifth vein with a distinct curvature near the
middle of the discal cell (p. 339) CHLOROPID^
Ocellar triangle small; fifth vein straight or without a sharp curvature.
(p. 325) DROSOPHILID^
55. Costa broken at the humeral crossvein 56
Costa not broken at the humeral crossvein 58
56. Postocellars divergent, if absent the arista absent.
(p. 332) AGROMYZID^ Postocellars convergent, parallel or absent, arista present 57
57. A pair of convergent frontal bristles anteriorlv; interfrontals often
present (p. 334) PHYLLOMYZIDJE
Anterior frontals not convergent (p. 325) DROSOPHILID^
58. Postocellar bristles convergent (p. 329) OPOMYZID^
Postocellar bristles divergent or absent 59
tablp: of families 25
59. Ocellar triangle large and shining, reaching the anterior edge of the
front (p. 356) CANACEID^
Ocellar triangle short 60
60. Second vein joining the costa just beyond the apex of the first.
(p. 328) ASTEIID.^ Second vein joining the costa far beyond the apex of the first 61
61. Custa fractured or weakened at the apex of the auxiliary vein 62
Costa not at all weakened (p. 323) PERISCELLID^
62. Oral vibrissse present (p. 332) AGR0MYZID7E
Oral vibrissge absent 63
63. Sternopleural bristle present (p. 329) OPOMYZID^
Sternopleural bristle absent (p. 374) PSILID^
64. Oral vibrissse present 65
Oral vibrissse absent 71
65. Mesonotum and scutellum convex, if rather flattened the abdomen and
legs not bristly 68
Mesonotum and scutellum flattened; legs and abdomen conspicuously bristly (p. 376) CCELOPID^
66. Postvertical bristles divergent 68
Postvertical bristles convergent 67
67. Orbital plates bearing the frontal bristles short and obliciue.
(p. 378) HELOMYZID^ Orbital plates long, extending to the anterior margin of the front or almost so ^ (p. 371) CHYROMYID.^
68. Second basal and discal cells separated 69
Second basal and discal cells confluent (p. 325) DROSOPHILID^
69. Anterior half of the front with strong bristles, two to four pairs present
on the front; third antennal segment short and rather orbicular, the
arista subapical T (p. 362) CLUSIID^
At most two pairs of rather weak frontal bristles situated on the pos- terior half; arista sub -basal 70
70. Eyes round; occiput convex and prominent (p. 310) PIOPHILIDi33
Eyes, vertical, elongate; occiput concave; antennae long.
(p. 298) LONCH^ID^
71. Legs long and slender, stilt-like; apical cell narrowed 72
Legs shorter and more robust, if rather long the apical cell not strongly
narrowed 75
72. Propleura haired 73
Propleura bare in the middle 74
73. Pteropleura haired on whole surface (p. 301) TANYPEZID^
Pteropleura bare on anterior half; second basal cell confluent witli the
discal (p. 306) MICROPEZID^
74. Arista apical (p. 308) NERIID^
Arista dorsal (p. 303) CALOBATID^
75. Apical cell closed or almost so in the wing margin; abdomen cylindrical,
the genitalia usually large (p. 265) CONOPID^
Apical cell not strongly narrowed or the abdomen short and broad 76
26 XOKTH AMERICAN DIPTERA
76. Some or all of the tibiae with preapical dorsal bristle 77
Tibiffi without preapical bristle 80
77. Postocellar bristles parallel, divergent or absent 78
Postocellar bristles convergent (p. 315) LAUXANIID.5:
78. Clypeus never prominent; femora with bristles 79
Clypeus very prominent; femora without bristles, (p. 382) DRYOMYZID^
79. Ovipositor flat and wide; front long and moderately narrow; head short,
hemispherical, the antennae never porrect; shining blackish flies.
(p. 298) LONCH^ID^ Ovipositor not prominent; front wide; head more or less orbicular or the front produced; antennae usually porrect; very rarely shining black (p. 367) TETANOCERID^
80. Antennae situated on the eye-stalks or at their base. (p. 358) DIOPSIDiSJ Antennae situated on the front, though widely separated, regardless of
the presence of eye-stalks 81
81. Ocelli absent (p. 268) PYRGOTID^
Ocelli present 82
82. Postocellar bristles convergent or absent 83
Postocellar bristles divergent or parallel 84
83. Posterior femora swollen and spinose beneath; abdomen clavate; small,
slender flies (p. 373) MEGAMERINID^
Posterior femora not swollen and spinose; abdomen short and rather broad, never clavate (p. 365) CHAM^MYID^
84. Presutural dorsocentrals absent or the subcostal and first veins end
far apart (p. 271) OTITID^
Presutural dorsocentrals present or the thorax bearing very long, fine pile (p. 296) PALLOPTERID^
85. Metascutellum developed, appearing as a strong convexity below the
scutellum; hypopleura with strong bristles (p. 415) TACHINIDiS]
Metascutellum weak or absent, or if developed there is only hair on the hypopleura 86
86. Oral opening and mouth parts very small; hypopleura with abundant
long hair 87
Oral opening normal; hypopleura with a row of bristles or only short, sparse hair 88
87. Scutellum extending far beyond the base of the metanotum; metascu-
tellum never developed.." (p. 411) CUTEREBRID^
Scutellum very short; metascutellum usually strongly developed; palpi usually large (p. 413) CESTRID^
88. Hypopleura with a row of bristles 89
Hypopleura with fine, short hair or bare 90
89. Apical cell strongly narrowed apically (p. 402) METOPIID^
Apical cell not at all narrowed apically (p. 384) MUSCIDjaC
90. Oral vibrissae absent; mesonotum without bristles except above the
wings (p. 374) PSILID^
Oral vibrissae present; mesonotum with bristles (p. 384) MUSCIDi9i]
27 PUPIPARA AND FLIES WITHOUT OR WITH ABORTED WINGS
91. CoxEe widely separated by the sternum; usually parasitic on warm
blooded animals 92
Coxae approximate basally; not parasitic on warm blooded animals (ex- cept Streblidae) 95
92. Mesonotum short, resembling the abdominal segments; antennae in-
serted in lateral grooves (p. 472) BRAULID^
Mesonotum and abdomen differentiated 93
93. Head small and narrow, folding back into a groove on the mesonotum;
prosteraum produced (p. 476) NYCTERIBIID^
Head not folding back in a special groove; prosternum not produced. . . .94
94. Palpi broader than long; wings uniformly veined., (p. 477) STREBLID/E Palpi elongate, forming a sheath for the proboscis; wing veins crowded
anteriorly, weak or absent posteriorly (p. 473) HIPPOBOSCID^
95. Antennae and mouth parts present 96
Antennje and mouth parts absent (p. 477) STREBLID^C
96. Antennae consisting of six or more freely articulated segments 97
Antennae consisting of at most three freely articulated segments 103
97. Mesonotum without a complete, V-shaped suture 98
Mesonotum with a complete V-shaped suture (p. 33) TIPULID^
98. Eyes meeting over the antennae 99
Eyes widely separated above the antenna 101
99. Abdomen enormouslv swollen, the apical four segments slender; termite
guests " (p. 101) CECIDOMYID^
Abdomen normal 100
100. Scutellum and halteres present (p. 131) SCATOPSID^
Scutellum and halteres absent (p. 118) SCIARID^.
101. Termite guests; ocelli absent; wings with several veins.
(p. 78) PSYCHODID/E Not termite guests 102
102. Halteres present (p. 69) CHIRONOMID^
Halteres absent (p. 120) MYCETOPHILID^
103. Antennae apparently consisting of one more or less globular segment;
posterior femora robust and laterally compressed. . (p. 234) PHORIDiSI Antennae with two or three quite evident segments; posterior femora not laterally compressed 104
104. Frontal lunule present 105
Frontal lunule absent (p. 205) EMPID^
105. First segment of the posterior tarsi short and swollen.
(p. 360) BORBORID^ First segment of the posterior tarsi longer than the second segment and not swollen 106
106. Arista with long, sparse rays (p. 325) DROSOPHILID^
Arista pubescent or bare; third antennal segment orbicular; wings
mutilated by the fly (p. 378) HELOMYZID^
28 NORTH AMERICAN DIPTERA
Superfamily Tipuloidea
These are the "Crane Flies" and include the families Tanyderidae, Ptychopteridaj, Trichoeerid«, Tipulidie and Anisopodidie. The first four mentioned families are characterized bv the presence of a V-shaped suture on the mesonotum, and have, until recent years constituted the family Tipulidte. In the Ptychopteridai this suture is more or less obsolete posteriorly where it extends into the prescutellar depression but its form is always very well marked. The inclusion of the Anisopo- didas with the Crane-Flies may be questioned by some students of the Order. I think the question is a debatable one : at any rate, the family seems to form more or less of a connecting link between the Tipulids and Mycetophilids.
The manuscript for the Tipuloidea has been prepared by Dr. C. P. Alexander and this fact assures the student of thorough and accurate keys together with the latest views on generic limits and classification. The study of this group might almost be said to be a ''world apart" in the study of Diptera and I cannot fully express my gratitude to Dr. Alexander for the service he has rendered in preparing this jJ^irt of the work.
29
Family Tanyderidae — The Primitive Crane Flies
Generalized flies of medium size, usually with a handsomely banded wing-pattern. iMouthparts often i)roduced. Antennge with from 15 to 25 segments; flagellar segments simple, cylindrical. Eyes with erect setJB between ommatidia; ocelli lacking. Latero-cervical sclerites some- times greatly elongated, short in the local species. Wings with five branches of Radius reaching the margin (*Fig. 11); most genera with one or two supernumerary crossveins in the outer radial or medial fields, these never exceeding two in any one genus, usually with a single such element. Male hypopygium with a single dististyle, usually simple, weakly bifid in the two regional genera. Aedeagus trifid.
The immature stages occur in sandy soil at margins of major streams, the larva being aquatic or nearly so.
There are 23 recent species of Tanyderida, distributed in 10 genera, chiefly Australasian in distribution. Two genera with three species occur in North America.
KEY TO GENERA
1. A supernumerary crossvein in cell M3 of the wing- (*Fig. 11).
Protoplasa Osten Sacken Wings without supernumerary crossveins Protanyderus Handlirsch
The most important recent literature is as follows: Alexander, C. P.
1919. The crane-fhes of New York. Part I. Distribution and taxonomy
of the adult flies. Cornell Univ. Agr. Expt. Sta., Mem. 25:
p. 883, 1 fig. 1927. Diptera. Fam. Tanyderidae. Genera Insectorum, Fasc. 189. 1930. Observations on the Dipterous family Tanyderidae. Proc. Linn.
Soc. New South Wales, Iv, pp. 221-230,' 2 pis., 1 fig. (larva
and pupa). Crampton, G. C.
1925. A phylogenetic study of the thoracic sclerites of the non-Tipuloid
Nematocerous Diptera. Ann. Ent. Soc. America, xviii, pp. 49-74, 5 pis.
1926. The external anatomy of the primitive Tanyderid Dipteran
Macrochile spectrum Lcew, preserved in Baltic Amber. Bull.
Brooklyn Ent. Soc, xxi, pp. 1-14, 2 pis. 1930a. Some anatomical details of the pupa of the archaic Tanyderid
Dipteron Protoplasa fitchii O. S. Proc. Ent. Soc. Washington,
xxxii, pp. 83-98, 3 pis. 1930b. A comparison of the more important structural details of the
larva of the archaic Tanyderid Dipteron Protoplasa fitchii, with
other Holometabola, from the standpoint of phylogeny. Bull.
Brooklyn Ent. Soc, xxv, pp. 239-258, 4 pis. Williams, Inez
1933. The external morphology of the primitive Tanyderid Dipteron
Protoplasa fitchii O. S., with notes on the other Tanyderidae.
Journ. N. Y. Ent. Soc, xli, pp. 1-36, 7 pis. (anatomy of adult;
comparative wing- figures of all genera of Tanyderidse).
* Plate II. Tipuloidea.
30 NORTH AaiERICAN DIPTERA
Family Ptychopteridae— The False Crane Flies
Antenna elongate, with 16 (Ptychopterinie) to 20 segments (Bit- tacomorphinse) ; flagellar segments cylindrical. Suture between prae- sciitum and scutum obsolete — posteriorly. Wings with R, preserved as a distinct element, lying far distad, subequal in length to Ri+s; three branches of Radius reach margin; two or three branches of i\Iedia; a single Anal vein (*Fig. 12).
The immature stages occur in saturated organic earth, the larvae with an elongate caudal breathing-tube, the pupie with a single greatly elongated pronotal breathing-horn.
There are two subfamilies, with 3 genera, PtycJioptera with 24 spe- cies, BittacomorpheUa with 3 species, Bittacomorplia with 2 species. In the New World, the family is found only in the Nearctic region, all genera being found on the eastern and western coasts but rare or lacking in the plains region.
KEY TO GENERA
1. Antennse 16-seffmented; wing:s with cell M,, present • (*Fiff. 12);
(Ptychopterinae) Ptychoptera Meig:en
Antennse 20-segmented; wings with cell Mi lacking; (Bittacomorphinae) . . 2
2. Wings with macrotrichia in distal ends of radial and medial cells; basi-
tarsi of legs not dilated BittacomorpheUa Alexander
Wings without macrotrichia in cells; basitarsi of legs conspicuously dilated Bittacomorpha Westwood
The latest literature on the family:
Alexander, C. P.
1919. The crane-flies of New York. Part I. Distribution and taxonomy
of the adult flies. Cornell Univ. Agr. Expt. Sta., Mem. 25, pp. 884-886, figs. 2-4.
1920. The same, Part II. Biology and Phylogeny. Ibid., Mem. 38, pp.
772-787, pis. 14-18, incl. (larva and pupa). 1927. Diptera. Fam. Ptychopteridae. Genera Insectorum, Fasc. 188, pp. 1-12, 1 pi.
Plate II, Tipuloidea.
31
Family Trichoceridae — The Winter Crane Flies
Small or medium-sized flies of slender build, the antennas elongate, setaceous. Three ocelli. Wings with m-cu lying far distad; two com- plete Anal veins, 2nd A very short, incurved to anal angle, slightly longer and more extended in Diazosyna. Male hypopygium with a single dististyle, this cylindrical or with a variously developed lobe on basal portion of mesal face. Ovipositor with cerci upcurved, the convexity being on the ventral surface.
The so-called "winter crane flies" are most numerous in Spring and Fall, though sometimes abundant during mild days of Winter. They are usually found in large to small swarms in the open, but may be found in cellars, mines and similar places. The immature stages occur in decaying vegetable matter.
There are 4 valid genera with about 45 described species. Tri- chocera is essentially a genus of the northern Hemisphere; Diazosma is represented only by 2 species, with a wide distribution in the Holarctic region. ParacJndura has several species in New Zealand and Chile, with a few others in eastern Asia; a single species (trichoptera O.S.) is found on our Pacific coast.
KEY TO GENERA
1. Wings with vein 2nd A subsinuate, not short and curved abruptly into
the anal angle; north temperate Diazosma Bergroth
Wings with vein 2nd A short, curved abruptly into the anal angle 2
2. Tibial spurs present; tarsi with basitarsus longer than segments 2 and
3 taken together; (* fig. 13); north temperate to arctic.
Trichocera Meigen Tibial spurs lacking; basitarsus very .short, only two or three times as long as wide, shorter than the third tarsal segment; western.
Paracladura Brunetti The most important recent literature:
Alexander, C. P.
1919. The crane-flies of New York. Part I. Distribution and taxonomy
of the adult files. Cornell Univ. Agr. Expt. Sta., Mem. 25, pp. 887-888, figs. 165, 166.
1920. The same. Part II. Biology and Phylogeny. Ibid. Mem. 38,
pp. 789-791, pi. 19 (larva and pupa). 1926. The Trichoceridae of Australia (Diptera). Proc. Linnean Soc. New South Wales, 51, pp. 299-304, 11 figs, (key to genera).
• Plate II, Tipuloidea.
32 NORTH AMERICAN DIPTERA
Edwards, F. W.
1928. Diptera. Fam. Protorhyphidae, Anisopodidas, Pachyneuridse, Tri- choceridas. Genera Insectorum, Fasc. 190, pp. 1-41, 2 pis.
Rhynehart, J. G.
1925. The larva and pupa of Trichocera regelationis L. Proc. Belfast Nat. Hist, and Phil. Soc, sess. 1922-1923, pp. 3-14, pis. 1-3.
33
Family Tipulidse — The Crane Flies
Tipula trivittata — adult, larva, pupa.
The present family, commonly called "'crane flies", includes slen- der-bodied flies, having long to very long, imnsually brittle legs that break readily between the trochanter and femur. From allied families of Nematocera, they are readily told by the lack of ocelli, two Anal veins, and the presence of the so-called V-shaped suture between the mesonotal pra?scutum and scutum. In many species there is a closed discal (1st M^) cell. In size, the various species show a range almost as great as that found in the entire order, from tiny flics witli a wing-
34 . NORTH AMERICAN DIPTERA
length of about 2 millimeters (as DasymoJophilus) to gigantic forms with a wing-length in excess of 45 millimeters {Ctenarroscelis).
Rostrum sometimes greatly elongated, in some {Elephantomyia: Toxorhina) produced by a great lengthening of the front, the reduced mouthparts being at the extreme tip; in others {Limonia: Geranomyia) the similarly greatly lengthened mouthparts consist chiefly of the labial palpi. In most Tipulidae the rostrum is short to very short. In many TipulinaB it is further tipped by a small nose-like point, the nasus. Max- illary palpi ranging in number of segments from 1 (some Limonia and Hexatoma: Conosia) to the normal number of 4. Antennae ranging in number of segments from 6 {Hexatoma) to 39 {Gynoplistia: Cero- zodia) ; sometimes very greatly lengthened in males, being one or more times the length of the entire body {Megistocera: Macromastix; Hexa- toma: Eriocera; Eliahdomastix) ; sometimes with branched flagellar segments (many Tipulina^; some Cylindrotominae; a few Limoniinge, as Limonia: Rhipidia and Gynoplistia) ; pedicel shorter than scape (except in some Eriopterine Claduraria) ; sometimes the basal flagellar segments united into a fusion-segment (Claduraria, Toxorhinaria). Eyes with ommatidia variable in size and coarseness; sometimes lioloptic (Li- monia), usually broadly dichoptic. Pediciini with short erect set^e between ommatidia.
Pronotum sometimes lengthened (some Limonia, Toxorhina) . Prae- seutum sometimes produced cephalad over pronotum {Conosia, T rente - pohlia) . Paired doul)le dots, tlie tuherculate pits, often present, one on either side of midline on ee])halic half of pr^escutum. PseudosiituraJ foveae often present as shiny depressions on humeral portion of prip- scutum. Postnotal pleurotergite sometimes produced into a tubercle (some Tipulinje). Halteres long to very long. Legs with trochanters short, rarely lengthened {Atarha, Rliahdomastix) ; tibiae with or without terminal spurs; claws simple or variously toothed {Limonia, Tipula). Wings of various shapes, sometimes long and narrow, the anal angle correspondingly reduced (some Limonia), sometimes with the region squarely developed {Antocha) . In cases, a pale longitudinal fold in cell Cu of wings (DicranoptycJia) . The details of venation are not discussed here, having been thoroughly considered by the present writer in recent papers that are cited in the morphological bibliography at end of paper and which may be consulted for details. The chief premise of the interpretation of the radial field is that the so-called radial cross- vein, r, of the Comstock-Needham system, has never been developed in the Diptera, the vein that has been so interpreted in the few families where it is found being the transverse free portion of R.,- The anterior branch of the radial field is labelled P^o' except in tlie su])tri])e Limoni-
PWMILY TIPULID.K THE CRANE FLIES 35
aria, where the free tip of vein Scg has migrated along vein R^ to occupy the extreme tip of the vein. A series of diagrams (Figs. 3 to 10) indi- cates this tendency, which involves many hundreds of species in the vast genus Limonia. The medial and cubital fields are interpreted ac- cording to the Tillyard modification of the Comstock-Needham system.
Male hypopygium usually simple, the basistyles (coxites) bearing the dististyles (styles) at or near apex. Aedeagus and its subtending gonapophyses furnishing characters of paramount importance for spe- cific determination. A dorsal lobe of the basistyle, the interbasc, some- times present. Ovipositor with the tergal valves (cerci) lengthened, heavily sclerotized, usually gently to strongly upcurved, exceeding the short, straight sternal valves (hypovalva?) ; in a few cases (as some TipulinjE; Cylindrotomina?; Styringomyia and others), the valves of the ovipositor are short and fleshy.
Tipulidae are great lovers of moist conditions, being chiefly re- stricted by humidity. Species have been taken within 600 miles of the North Pole, while others occur at altitudes of over 17,000 feet in Thibet. The majority of the species occupy the intermediate zone, the familj^ being very numerous in species in all temperate parts of the World and similarly numerous in the subtropical and temperate portions of the mountainous regions of the Tropics. Lowland tropical species are fewer in luiniber and are apt to have a very wide distribution. The lesser oceanic islands are practically devoid of the larger crane flies (TipulinaO while having numbers of species of the small fragile Li- moniina^ (as Limonia, s.l.; Stf/rinffomj/ia; Gononii/ia: Lipophleps; Tren- tepohlia). ITnder rigorous conditions, as the arctic, wind-swept coasts, high mountains and the like, species with reduced wings are frequently found, being most numerous in the female sex. The greatest reduction of wings is found in Chionea, wliich is virtually apterous in both sexes.
The Tipulidtr of the World now include more than 6000 species, arranged in 2S3 genera and subgenera (Tipulinse, 76, Cylindrotominte, 9; Limoniina', 198, the latter further distributed in the following tribes: Lechriini, 4; Limoniini, 37; Pediciini, 12; Hexatomini, 70, and Eriop- terini, 75). Representatives of all tliree sulifamilics and of all tribes witli tlie exception of the Tjcchriini occur in tlie area under considera- tion.
Keys availalile for tlie idi'utification of tlie adult flies are very few in number. The writer's preliminary study on the "Crane flies of New York", is now seriously out-of-date due to the great additions made in intervening years. The forthcoming volume on Diptera in the "In.sects of Connecticut'' series will largely supercede the earlier work. Both of these reports are restricted to the area embraced in northeastern
36 NORTH AMERICAN DIPTERA
North America. No ke,ys are available for most of the groups in other regions of the continent, with the exception of the papers listed in the bibliography on certain groups of Tipulidae, which are lessened in value due to the great additions that liave been made in later years.
KEYS TO SUBFAMILIES AND TRIBES, GENERA, ETC.
1. Terminal .segment of maxillary palpus elongate, whiplash-like; nasus
usually distinct; antennae usually with 13 segments; wings with Sci usually atrophied; vein Cu, constricted at m-cu, the latter usually at or close to fork of M3+4 (1, 17 to 20); body-size usually large.
(Tipulinas) ". " 2
Terminal seg-ment of maxillary palpus short; no distinct nasus; an- tennae usually with 14 or 16 segments; wings with Sci present, its extreme tip atrophied in some Cylindrotomin^; vein Cui straight, not constricted at m-cu, the latter placed far before the fork of M3+4, usually at or close to fork of M (21 to 44); body-size usually small or medium 19
2. Legs unusually long and filiform; wings with vein Ri+j atrophied and
with Sci ending in Sc close to origin of Rs (Dolichopeza, 19), when Ri+! is preserved (Brachyprenina, 18; Tanypremna; Megis- tocera, 17), vein Sc is very long, Sci reaching C as a distinct element some distance beyond fork of Rs and with cell 2nd A usually
very narrow (Dolichopezaria) 3
Legs of normal stoutness for the family; wings with vein Ri+j pre- served (20); when atrophied (a few species of Tipula) with Sc of moderate length, Sc, atrophied before fork of Rs and Scj ending at or near midlength of Rs (exception, some species of Longurio); cell 2nd A of noiTnal width 8
3. Wings with origin of vein Mi basad of that of M,+2; R2+3 angularly
bent at near midlength (17); tropical, subtropical.
Megistocera Wiedemann Wings with origin of vein Mt distad of that of Mi+;, usually far be- yond; R2+3 straight or nearly so, not angulated 4
4. Wings with R,+2 pale, perpendicular to R2+3; Rs strongly arcuated at
origin (18) Brachypremna Osten Sacken
Wings with R1+2, when present, oblique; Rs straight or gently arcuated throughout length, sometimes very short and transverse 5
5. Rs of moderate length, subequal to m-cu; Sc long, Sc, preserved,
ending beyond fork of Rs; R,+2 pale but preserved; tropical.
Tanypremna Osten Sacken Rs short, transverse, simulating a crossvein, about equal in length to one-half m-cu; Sc unusually short, Sc, atrophied, Sc2 entering Sc before to just beyond origin of Rs; R,+2 atrophied. (Dolichopeza) (I
6. Wings with cell 1st M2 open by atrophy of basal section of Ms, the
outer medial field thus appearing pectinately branched (19);
temperate Dolichopeza: Dolichopeza Curtis
Wings with cell 1st M2 closed 7
7. Cells beyond cord with abundant macrotrichia; tropical.
Dolichopeza: Megistomastix Alexander Cells beyond cord glabrous; temperate. . . .Dolichopeza: Oropeza Needham
FAMILY TIPULID.E — THE CRANE FLIES 37
8. Antennal flag-ellum of male branched, of female branched or serrate;
legs relatively short and stout. (Ctenophoraria) 9
Antennal flagellum simple (serrate in Prionocera, readily told by lack of antennal verticils); legs usually more slender. (Tipularia) 11
9. Antenna of both sexes with two short branches at extreme base of
flagellar segments two to seven inclusive; tropical.
Ozodicera: Dihexaclonus Enderlein Antennae of male with three or four branches on each of flagellar segments two to nine, of female merely serrate; north temperate. . 10
10. Antennas of male with three pectinations on flagellar segments two
to nine, each segment with a single branch on apical half, in addition to the usual basal pair; ovipositor greatly elongated,
sabre-like Tanyptera Latreille
Antennae of male with two pairs of pectinations on flagellar segments two to nine, one pair being subbasal, the other subapical; ovipos- itor short and of normal Tipuline structure Ctenophora Meigen
11. Wings with vein R3 bent strongly caudad before end, thence angu-
larly deflected cephalad, cell R3 thus being much constricted at
near midlength; western and tropical Holorusia Loew
Wings with vein R3 straight or only gently arcuated throughout its length, not constricting the cell (20) 12
12. Flagellar segments without verticils, the lower face of individual
segments produced to give the organ a serrate appearance; terminal flagellar segment abruptly more slender, north temperate to arctic.
Prionocera Loew Flagellar segments verticillate, simple or nearly so 13
13. Abdomen in both sexes greatly elongated, somewhat resembling that
of a dragon-fly; verticils of outer flagellar segments very long and conspicuous; valves (cerci) of ovipositor with smooth margins;
eastern. (Longurio) 14
Abdomen not so elongated (except in female of Tipula longiventris Lw., which has the cerci of ovipositor serrate on margins); anten- nal verticils of moderate length only 15
14. Wings with cell M, sessile Longurio: .^schnasoma Johnson
Wings with cell M, petiolate Longurio: Longurio Loew
15. Wings with Rs short and oblique in position, shorter than m-cu; cell
M, sessile or very short-petiolate; vein Mi arising opposite or basad of origin of M,+:.; body-coloration highly polished, often black and
yellow Nephrotoma Meigen
Wings with Rs elongate, exceeding m-cu; cell M, petiolate; vein M, arising distad of origin of M,«; body-coloration usually opaque, pruinose or pollinose (20). (Tipula) 16
16. Wings with cell M, lacking; arctic Tipula: Nesotipula Alexander
Wings with cell Mi present 17
17. Size very small (wing not exceeding 9 mm.); vein Rn2 entirely
atrophied; tropical Tipula: Microtipula Alexander
Size larger (wing over 10 mm.; in species with R,.^ atrophied, wing over 12 mm.) ; R,+:. usually preserved 18
38
NORTH AMERICAN DIPTERA
Sc2*R, Sc,
Cu, M^
r-ra
i?3 10
Tipuloidea, Plate I.
FAMILY TIPULID.E — THE CRANE FLIES 39
EXPLANATION OF PLATE
1. Tanyptera fumipennis, venation.
2. Dicranota (Plectromyia) modesta, venation.
3-10. A series of diagrams to illustrate the modification of the outer subcostal and radial fields of the wing-, as found in the Tipulinse, Cylindroto- minje, Lechriini and Limoniini.
3. The type found in the Orimargaria: Scs preserved, R1+2 complete, at-
taining the wing-margin.
4. A further development of 3. . Sc'. has moved distad, shortening Ri; Ri^o
still entire.
5. Condition as in 4 but with tip of Ri+2 atrophied. Found in several Ori-
margaria, Limoniaria.
6. An accentuation of 5. The atrophy of R,+: is still greater, R, more
shortened and more or less in transverse alignment with the fi'ee tip of Sc;. Condition found in numerous Limoniaria.
7. A still further modification of 5. The atrophy of R1+2 is now complete
and Ri is in direct transverse alignment with R^, both in turn being in transverse alignment with the free tip of Sc;. This is the com- monest type in the Limoniaria, being found in most members of the following subgenera of Limonia, — Dicranomyia, Geranomyia and Rhipidia, as well as in some Limonia, s.s.
8. A type that reverts back to condition 5, with a long spur of R1+2 persist-
ing, with the free tip of Sc2 migrated distad along this spur to lie beyond the level of R2. A condition found in several subgenera of Limonia, as Peripheroptera, Limonia and Libnotes.
9. A further modification of 8, where Sc2 has migrated to the extreme tip
of the spur of Ri+i but still forms a rectangular bend. Limonia: Libnotes.
10. The culmination of the series, where the free tip of Sca has migrated to the extreme tip of the spur of Rn2 and then bends to the costal margin at a gently oblique angle. This condition is common in many Limonia of the subgenera Limonia and Discobola.
EXPLANATION OF SYMBOLS Comstock-Needham system, as modified by Alexander and Tillyard
C = Costa; Cu = Cubitus; 1st M2 = cell 1st M^; M = Media; m-cu = me- dial-cubital crossvein; R = Radius; r-m = radial-medial crossvein; Rs^ Radial sector; s =: supernumerary crossvein; Sc = Subcosta; A = Anal veins.
40
NORTH AMERICAN DIPTERA
C Sc, R
Co, Ml
1st A Cii
^5 16
Cii, IW,
Cu, IH4
laiX
1st A M, ^'
2nd A
1st A
2adA-
Cu, N,
Tipuloidea. Plate 11. — 11. Protoplasa fitchii, venation: 12. Ptychoptera rufocincta, venation; 13. Trichocera colei, venation; 14. Anisopus alteinatus, venation; 15. Axymyia furcata, venation ; 16. Mycteboia divergens, venation ; IT. Megistocera longipennis. venation ; 18. Brachypremna dispellens, venation ; 19. Dolichopeza (Dolichopeza) ameiicana, venation ; 20. Tipula (Tipula) dorsomacula, venation.
FAMILY TIPULID-E THE CRANTE FIJES 41
18. Wings with macrotrichia in apical cells. ..Tipula: Trichotipula Alexander Wing-s with cells glabrous Tipula: Tipula Linnaeus
19. Wings with tip of Ri+; atrophied, giving the appearance of a long
fusion back from margin of veins R, and anterior branch of Rs;
free tip of Sc.. preserved (21, 22, 23) (Cylindrotomin^) 20
Wings sometimes with tip of R,.; atrophied (some Limoniini) but not giving the appearance of a long fusion backward from margin of veins R, and anterior branch of Rs; free tip of Sc2 preserved in many species of tribe Limoniini, lacking in other tribes in this fauna (24 to 44) (Limoniinie) 24
CYLINDROTOMIN^: GENERA
20. Head and intervals of mesonotal praescutum with numerous deep
punctures; a deep median groove on prtescutum. . . . Triogma Schiner Head and intervals of mesonotal praescutum smooth; no median praescutal groove 21
21. Three branches of Radius reach the margin, Ri« being presei'ved as
a distinct element Phaiacrocera Schiner
Two branches of Radius reach the margin, Ri^:: being entirely atrophied, giving the appearance of a long backward fusion of veins R, and anterior branch of Rs (21-23) 22
22. Four branches of Media reach the margin (21) . .Cylindrotoma Macquart Three branches of Media reach the margin 23
23. Wings with crossvein r-m present; outer end of cell 1st Mj almost
always closed by a single transverse vein, cell M, being present, sessile to short-petiolate; cells 2nd M- and Ma confluent by atrophy 01' partial atrophy of distal section of vein M^; antennae nearly simple, the lower face of individual segments not produced (22,
23 ) Phalacrocera Schiner
Wings with crossvein r-m usually shortened to quite obliterated by the approximation or fusion of veins R4+.-, and Mi+;.; outer end of cell 1st Ms closed by two transverse veins, these being M and the basal section of Ms; cell M, lacking, cells 2nd M^. and M3 distinct; antennae strongly nodulose, especially in male, the individual flagel- lar segments nearly cordate Liogma Osten Sacken
TRIBES OF LLMONIIN^
24. Eyes hairy; wings with vein Sci very long, Sc? lying basad of origin
of Rs (2, 30). (Pediciini) ". . . 41
Eyes glabrous; wings with Sci short or of moderate length, when long (some Eriopterini), Sc2 lying distad of origin of Rs; where Sc2 lies basad of origin of Rs (some Limoniini, Eriopterini), the entire vein Sc is shortened 25
25. Wings with free tip of Sca often present; veins Rj and R-, fused to
margin, only two branches of Rs being present; antennae usually with 14 (Limoniaria) or 16 segments; (4-10, 24-29) (Limoniini).. 27 Wings with free tip of Sc- atrophied; veins R4 and Rr, separate, the former usually transferred to the upper branch, R2+3, to form a distinct element R;+s.4; usually with three branches of Rs present (except in Atarba, Elephantomyia, Styringomyia, Teucholabis, Go- nomyia and Toxorhina, where Rj is captured by R^^s, as above); antenna; usually with 16 segments; (31-44) 26
42
NORTH AMERICAN DIPTERA
2nd A
2adA
1st A ^"'
2nd k 1st A
2adA
Co, M,
2nd A
2nd A
1st A
2nd A
1st A Cu,,
1st A Cn,
1st A Cu,
Tipuloidea, Plate 111.-21. C.Undrot„„.a tarsal!, ^^ation: 22^ Pha^ro^ venation'; 2P,. Phalacocera ""'d-^*-^-; -^^Xepla) Kw^ 2-- D-ranoptycha
(Hclius) flavipes, venation ; 26. ^"'"'''^^^J" °™ (Limonia) hnmatura, vena .on
Sf^'-^^aiTHcSo^'Sotr'^atrf'^-Sexatcna (He.ato.na) .e.acera. venat.on . 32: Hexatoina (Eriocera) longicornis, venation.
FAMILY TIPULID.E THE CRANE FLIES 43
26. Tibial spurs present. (Hexatomini) '. . . 51
Tibial spurs lacking. (Eriopterini) 78
LIMONIINI: SUBTRIBES, GENERA, SUBGENERA
27. Wings with vein R2 lacking (25) 28
Wings with vein Ra present (24, 26, 29) 29
28. Rostrum short and inconspicuous; Rs long and straight, running close
to R, and in alignment with Rlvs) r-m distinct. (Ellipteraria).
Elliptera Schiner Rosti'um of moderate length, about equal in length to remainder of head; Rs short, gently arcuated, not in alignment with R-..-3; r-m often shortened or obliterated by approximation of adjoining veins (25). (Heliaria) Helius St. Fargeau
29. Wings with m-cu more than three, (and usually much more), times
its own length before the fork of M (26). (Orimargar"a, Orimarga) 30 Wings with m-cu close to or beyond the fork of M, if before, the distance not or scarcely exceeding the length of the vein itself (24, 27, 29 ) '. 31
30. Wings with three branches of Media reaching margin, cell M3 being
present; m-cu beneath Rs Orimarga: Orimarga Osten Sacken
Wings with two branches of Media reaching margin, cell M3 lacking; m-cu far before origin of Rs (26). .Orimarga: Diotrepha Osten Sacken
31. Wings with vein R2 lying far distad, beyond level of outer end of
cell 1st M::; m-cu beyond fork of M (27) (Dicranoptycharia).
Dicranoptycha Osten Sacken Wings with vein R2 in almost transverse alignment with r-m and basal half of cell 1st M^; m-cu at or slig-htly before fork of M (24, 28, 29) 32
32. Wings with Rs long and straight (24, 28); antennae IG-segmented. . . 33
Wings with Rs shorter and more arcuated (21); antennae 14- segmented. (Limoniaria, Limonia) 34
33. Anal angle of wing very prominent, almost square; Rs long, diverg-
ing at an acute angle from R,, ending approximately between the branches of Rs or in alignment with R4.5 (28) (Antocharia).
Antocha Osten Sacken Anal angle of wing normally rounded; Rs long, lying very close to Ri and nearly parallel to it, its end in alignment with R2+3; basal section of R-.^., short and arcuated, diverging from the end of Rs at nearly a right angle (24) (Ellipteraria) Elliptera Schiner
34. Wings with M and both sections of M3 lacking, cell Ms thus entirely
obliterated Limonia : Alexandriaria Garrett
Wings with at least the distal section of M3 preserved and usually with both sections, together with m, cell M3 thus usually present (29) 35
35. Supernumerary crossveins present in certain cells of wing 36
No supernumerary crossveins in cells of wing (excepting a weak
element sometimes evident in cell Sc) (29) 37
44
NORTH AMERICAN DIPTERA
TiiMjloidea, Plate IV. — 33. Elephantomyia westwoodi, venation ; 34. Atarba (Atarba) picticornis, venation ; 35. Polymera (Pol.vmera) rogcrsiana, venation : 36. Prolimnophila areolata, venation ; 37. Toxorhina (Toxoihina) niuliebris, venation ; 38. Teucholabis (Tcuchoiabis) complexa, venation; 39. Trentepohlia (Paiamongoma) bromeliadicola, venation; 40. Gonoinyia (Gonomyia) subcinerea, venation: 41. Molophilus nitidus, venation; 42. Helobia hybrida, venation; 43. Gnophomyia tristissima, venation; 44. Erioptera (Erioptera) sep- tointrionis, venation.
FAMILY TIPULID.E THE CRANE FLIES 45
36. Wing's with Sc short, Sci ending opposite or before origin of Rs;
a supernumerary crossvein in cell R3. .Limonia: Neolimnobia Alexander Wings with Sc long-, ending about opposite fork of Rs; a super- numerary crossvein in cell 1st A, connecting the Anal veins.
Limonia: Discobola Osten Sacken
37. Mouthparts, and especially the labial palpi, lengthened, the rostrum
much longer than remainder of head, and usually about as long as
the combined head and thorax Limonia: Geranomyia Haliday
Mouthparts, with the labial palpi, not notably lengthened, shorter than remainder of head 38
38. Antenuje of male more or less branched (bipectinate, unipectinate or
subpectinate), of female simply serrate, sometimes very weakly so.
Limonia: Rhipidia Meigen Antennge simple in both sexes 39
39. Wings of male with the prearcular region greatly developed, of
female less markedly so; wing-apex very obtuse; Sc: ending ap- proximately opposite origin of Rs; tropical.
Limonia: Peripheroptera Schiner Wings of both sexes with prearcular cells small and inconspicuous; wing-tip not so obtusely rounded (except in some Limonia, s.s., where Sc is elongate, ending beyond midlength of Rs) 40
40. Wings with Sc short, Sc, ending opposite or before origin of Rs.
Limonia: Dicranomyia Stephens Wings with Sc long, Sc, ending beyond midlength of Rs (29).
Limonia: Limonia Meigen
PEDICIINI: SUBTRIBES, GENERA, SUBGENERA
41. Wings with numerous macrotrichia on membrane (Ularia) . .Ula Haliday Wings glabrous 42
42. Rostrum produced into a beak that is subequal in length to remainder
of head; western Ornithodes Coquilletl
Rostrum only inconspicuously developed 43
43. Antennae with usually 16 segments; size large, wing usually over
10 mm. (P'edicia) 44
Antennse with usually 13 or 15 segments; size small, wing usually under 8 mm 45
44. Size very large (wing, 20 mm. or more); wings with a dark pattern
that is arranged as a triangle, including broad costal and cubital seams that are connected across the very oblique cord; maxillary
palpus with terminal segment elongate Pedicia: Pedicia Latreille
Size smaller (wing, under 18 mm.); wings without a dark pattern arranged as a triangle, as above described; cord of wing trans- verse or nearly so (30); maxillary palpus with terminal segment short Pedicia: Tricyphona Zetterstedt
45. Wings with four supernumerary crossveins, located in cells R,, R3, R4
and M; western Polyangaeus Doane
Wings with at most a single supernumerary crossvein, this in cell Ri, basad of vein R2 (Dicranota) 46
46. A supernumerary crossvein in cell R, about opposite end of vein Sd. 47 No supernumerary crossveins in cells of wing- 49
46 NORTH AMERICAN DIPTERA
47. Cell 1st M2 closed; eastern Dicranota: Eudicranota subg. n.
Cell 1st M2 open by atrophy of m 48
48. Cell M, lacking Dicranota: Paradicranota subg. n.
Cell Ml present Dicranota: Dicranota Zetterstedt
49. Cell 1st M2 closed; eastern Dicranota: Amalopina Brunetti
Cell 1st M; open by atrophy of m 50
50. Cell Ml lacking (2) Dicranota: Plectromyia Osten Sacken
Cell Ml present Dicranota: Rhaphidoiabis Osten Sacken
HEXATOMINI: SUBTRIBES, GENERA, SUBGENERA
51. Antennas with not more than 12 segments (Hexatomaria, Hexatoma). 52 Antennae with more than 14 segments 54
52. Cell 1st M2 open; two branches of M reach the wing-margin (31);
eastern Hexatoma: Hexatoma Latreille
Cell 1st M2 closed; three or four branches of M reach the wing- margin (32) 53
53. Feet snowy- white; eastern and tropical. .Hexatoma: Penthoptera Schiner Feet not white (32) Hexatoma: Eriocera Macquart
54. Wings with only two branches of Rs present; vein R2 lacking 55
Wings with three branches of Rs present; vein R2 presei*ved (except
in Phyllolabis) 5G
55. Rostrum elongate, exceeding one-half the length of the entire body
(33) ; (Elephantomyaria) Elephantomyia Osten Sacken
Rostrum short and inconspicuous, not exceeding the remainder of head (34); eastern and tropical (Atarbaria).
Atarba: Atarba Osten Sacken
56. Apical cells of wing with macrotrichia 57
Cells of wing without macrotrichia (excepting in stigmal area) 61
57. A supernumerary crossvein in cell M; eastern (Limnophilaria).
Limnophila: Trichephelia Alexander No supernumerary crossvein in cell M 58
58. Cell R3 of wings sessile, subsessile or short-petiolate; Rr+s+i lacking
or much shorter than m-cu. (Limnophilaria) 59
Cell Rs of wings long-petiolate, R2+3+4 being as long as or longer than m-cu 60
59. Wings with macrotrichia abundant, involving the cells basad of cord.
Ulomorpha Osten Sacken Wings with sparse macrotrichia in cells beyond cord only.
Limnophila: Lasiomastix Osten Sacken
60. Small species (wing, 0", less than 5 mm.); cell Mi usually present; an-
tennae short in both sexes (Adelphomyaria) . . . . Adelphomyia Bergroth Larger flies (wing, c^", over 6 mm.); cell Mi lacking; antennae of male very long; tropical (Limnophilaria) Shannonomyia Alexander
61. A supernumerary crossvein in cell C (Epiphragmaria).
Epiphragma Osten Sacken No supernumerary crossvein in cell C (35) 62
FAMILY TIPULID.E — THE CRANE FLIES 47
62. Wing-s with vein R- lacking; m-cu at outer end of cell 1st M^; western.
Phyllolabis Osten Sacken Wings with vein R.. present; m-cu at or before two-thirds the leng-th of cell 1st M;, when the latter is present (35, 36) 63
63. Wings with cell 1st M2 open by atrophy of m (3.j); male with
elongate nodulose antennae; tropical and subtropical.
Polymera: Polymera Wiedemann Wings with cell 1st M- closed; antennae of male not nodulose 64
64. Wings with Sc very long, Sc, R1+2 and R3 all ending close together
at costal margin; tropical Psaronius Enderleiii
Wings with Sc short, widely separated from either Ri+; or R3 (36) . . . 65
65. Wings with m-cu at or close to fork of M; anterior arculus lacking.
(Dactylolabaria) Dactylolabis Osten Sacken
Wings with m-cu beyond the fork of M, at from one-third to about one-half the length of cell 1st M^; where close to fork of M (some Pseudolimnophila) the arculus complete 66
66. Wings with the anterior arculus lacking (36) (Pseudolimnophilaria,
in part) 67
Wings with the anterior arculus present 6S
67. Cell 1st M2 of wings very large, its inner end lying far proximad of
the other elements of the cord (36) Prolimnophila Alexander
Cell 1st M; of wings of normal size, its inner end straight and in ap- proximate alignment with the elements of the anterior cord.
Archilimnophila, g. n.
68. Wings with Sc relatively short, Sci ending before the level of the fork
of Rs; where slightly longer (Limnophila albipes Leonard) the pos- terior tarsi snowy-white. (Limnophilaria, in part) 69
Wings with Sc longei", Sc: ending opposite or beyond the fork of Rs; (compare some species of Pilaria, distinguished by having the an- tennal verticils of unusual length) 70
69. Antennae with long conspicuous verticils; tuberculate pits present,
small, placed at extreme cephalic end of prsescutum; Rs elongate,
exceeding vein R3; cell Mi present or lacking Pilaria Sintenis
Antennge with short verticils; tuberculate pits lacking; Rs short and strongly arcuated or angulated at origin; cell M, lacking.
Shannonomyia Alexander
70. Head strongly narrowed and prolonged behind; radial and medial
veins beyond cord long and sinuous; vein R3 extending generally parallel to vein R4, not diverging markedly at tips; vein 2nd A strongly curved to margin (Pseudolinmnophilaria, in part).
Pseudolimnophila Alexander Head broad, not conspicuously narrowed behind; radial and medial veins beyond cord more nearly straight; vein R3 diverging strongly from vein R4, cell R3 conspicuously widened at margin; vein 2nd A not curved strongly into margin (Limnophilaria, in part, Limno- phila).
71. Supernumerary crossveins in either cell R3 or cell M of wing 72
No supeimumerary crossveins in cells of wing 74
48 NORTPI AMERICAN DIPTERxV
72. A supernumerary crossvein in cell R3; eastern.
Limnophila: Dicranophragma Osten Sacken A supernumerary crossvein in cell M 73
73. Rs long-spurred at origin; antennge of male elongate.
Limnophila: Idioptera Macquart Rs slightly if at all spurred at origin; antennae short in both sexes.
Limnophila: Elaeophila Rondani
74. Cell R3 sessile; cell M, lacking Limnophila: Idiolimnophila, subg. n.
Cell R3 petiolate; cell Mi present 75
75. Very large species (wing over 16 mm.); wings with the branches of
M leaving the main stem at a strong angle, cell 1st M2 thus being
strongly hexagonal; eastern Limnophila: Eutonia Van der Wulp
Smaller species (wing under 14 mm.); wings with the branches of M not strongly divergent, especially M3+4, cell 1st Mj being more nearly rectangular in outline 76
76. Wings with vein R2+3+4 short, subequal to the basal deflection of Rs;
Rs elongate, exceeding four times R3+3+4; coloration polished black or gray, the latter group having the male hypopygium with a series of teeth on margin of outer dististyle, producing a comb-like ap- pearance Limnophila: Prionolabis Osten Sacken
Wings with R2+3+4 longer, usually exceeding the basal deflection of Rr,; Rs shorter, not exceeding three times R2+3+4; where the above characters are doubtful, the species have a closely iri-orate brown wing-pattern; body coloration never polished black; when gray, male hypopygium without a comb of spines on outer dististyle .... 77
77. Rs short, weakly to more strongly angulated at origin, more rarely
merely arcuated; R2+3+4 subequal to or shorter than m-cu; an- tennae short in both sexes Limnophila: Phylidorea Bigot
Rs longer, more gently arcuated; in species with shorter Rs, antennae of male elongate and usually with R2+3+4 long, considerably exceed- ing m-cu Limnophila: aberrant species
ERIOPTERINI: SUBTRIBES, GENERA, SUBGENERA
78. Nearly apterous, the wings reduced to microscopic structures that
are smaller than the halteres; northern. (Claduraria) .Chionea Dalman Fully-winged species 79
79. Wings with cell Mi present SO
Wings with cell Mi lacking (37-44) 84
80. Antennae with the basal two to four segments united into a fusion-
segment; wings with R2+3+4 much longer than the short basal section of R:,; veins Sc, and R1+2 widely separated at margin, the distance on Costa between them approximately three times r-m; legs plainly
colored; temperate. (Claduraria) 81
Antennae with all flagellar segments distinct; wings with basal sec- tion of R5 elongate, much exceeding R2+3+4; veins Sci and R1+2 closely approximated at margin, the distance on costa between them subequal to or shorter than r-m; legs conspicuously hairy, banded with black, rufous and white; tropical. (Lecteriaria).
Lecferia Osten Sacken
FAMILY TIPULID.E THE CRANE FLIES 49
81. Wings with R2+3t4 subequal to or longer than vein Ri, cell R3 thus
being subequal to its petiole; vein R; at or before the fork of Riit4.
Neolimnophila Alexander Wings with R-..+3+4 shorter than vein R3, cell R3 being much longer than its petiole; R; far beyond fork of R2+3t4 82
82. Wings with cell Mi very small, about one-third its petiole; fusion-
segment of antenna very long, about equal to the succeeding four
segments combined; western Pterochionea Alexander
Wings with cell M, subequal to or longer than its petiole; fusion- segment of antennae shorter, about as long as the succeeding two or three segments combined. (Cladura) 83
83. Wings with Rit- elongate, exceeding R2+3+4; R2+3 subequal to m-cu;
male hypopygium with two dististyles. .Cladura: Neocladura Alexander Wings with R,+; shorter than R2+3+4; R2+3 approximately twice m-cu; male hypopygium with a single powerful dististyle.
Cladura: Cladura Osten Sacken
84. Rostrum very long and slender, approximately one-half the entire
body or longer; setae of legs profoundly bifid (Toxorhinaria,
Toxorhina ) 85
Rostrum short, not exceeding remainder of head; setas of legs simple. 86
85. Wings with Rs having a single branch (37); eastern and tropical.
Toxorhina: Toxorhina Osten Sacken Wings with Rs having two branches; tropical.
Toxorhina: Ceratocheilus Wescht§
86. Two branches of Rs reach the wing-margin (38) 87
Three branches of Rs reach the wing-margin (39-44) 89
87. Wings with Ri ending before midlength; anterior branch of Rs
diverging strongly from posterior branch, arising at or close to r-m, straight and oblique; tropical. (Styringomyaria) . .Styringomyia Lcew Wings with Ri ending about opposite two-thirds their length; branches of Rs subparallel on basal half. (Gonomyaria) 88
88. Wings with R,. present, close to fork of Rs; Sc usually long, Sc,
ending beyond origin of Rs (38); some eastern, jjut chiefly
tropical Teucholabis: Teucholabis Osten Sacken
Wings with R- lacking; Sc short, Sc, ending opposite or before origin of Rs; chiefly tropical (Gonomyaria). . .Gonomyia: Lipophleps Bergroth
89. Wings with R,, fused with Mi+; to form the entire cephalic face of
cell 1st M2, r-m thus obliterated; only two branches of M reach the margin; vein 2nd A very short (39); tropical. (Trentepohliaria).
Trentepohlia: Paramongoma Brunetti Wings with R,-, entirely distinct from M1+2, being separated by the r-m crossvein (the veins fused only in a few species of Paratro- pesa, where the alternative characters hold); three branches of M reach the mai'gin; vein 2nd A of normal length (40-11) 90
90. Wings with cell R3 short, vein R3 shorter than the petiole of cell R3
(40) 91
Wings with cell R3 deep, vein Rj longer than the petiole of cell R3 (42-44); shortest in Progonomyia and Empedomorpha 99
50 NORTH AMERICAN DIPTERA
91. Wings with vein R: present 92
Wings with vein R- lacking 95
92. Rs at end of Rs, in alignment with the other elements of the cord;
r-ni obliterated by the long fusion of veins R4+5 and M,+2; tropical.
(Gonomyaria) Teucholabis: Paratropesa Schiner
R; its length or more beyond the fork of Rs, R2+3+4 subequal to or longer than R2; r-m distinct 93
93. Wings with Rs long and straight, exceeding the distal section of
M1+2; tuberculate pits on cephalic portion of prsescutum; trochanters elongate; arctic and subarctic. (Rhabdomastix).
Rhabdomastix: Sacandaga Alexander Wings with Rs shorter, less than the distal section of M,+2; tubercu- late pits removed from cephalic margin of prsescutum; ti'ochanters short. ( Erioptera ) 94
94. Wings with veins R3 and R4 strongly diverging, cell R3 having a
Gonomyia-like shape Erioptera: Gonempeda Alexander
Wings with veins Rs and Ri more generally parallel, cell R3 having the more normal Erioptera-shape, but shorter.
Erioptera: Empeda Osten Sacken
95. Wings with Sc long, Sci extending to near opposite or beyond mid-
length of Rs; m-cu at or beyond fork of M. (Eriopteraria, Rhab- domastix ) 96
Wings with Sc short, not extending to beyond midlength of Rs; if Sc is relatively long (Ptilostena), m-cu lies more than its own length before the fork of M. (Gonomyaria, Gonomyia) 97
96. Antennae of male longer than body; chiefly tropical
Rhabdomastix: Rhabdomastix Skuse Antennae of male scarcely attaining wing-ioot; chiefly temperate.
Rhabdomastix: Sacandaga Alexander
97. Wings with m-cu more than its own length before form of M.
Gonomyia: Ptilostena Bergroth Wings with m-cu at or very close to fork of M (40) 98
98. Wings with cell R3 very small, at margin subequal in extent to cell
R.>; antennal verticils long and conspicuous.
Gonomyia: Lipophleps Bergroth Wings with cell R3 larger, at margin considerably exceeding in extent cell R.; antennal verticils not conspicuously elongated.
Gonomyia: Gonomyia Meigen
99. Wings with distinct macrotrichia in outer cells 100
Wings with the outer cells glabrous 103
100. Wings with Rs shortened, its union with R2+3+4 forming an angle, so
cell Ri is nearly equilateral in outline; chiefly tropical. (Eriop- teraria) Cryptolabis Osten Sacken
Wings with Rs long, normal in position, cell Ri elongate 101
101. Size very small (wing, 3 mm. or less); Rs ending in cell R3, this cell
thus being sessile, without element R-+3+4; temperate. (Eriop- teraria) Dasymolophilus Goetghebuer
Size larger (wing over 4 mm.); Rs ending in cell R4, cell R3 being petiolate by the presence of a distinct element R;+3.4 102
FAMILY TIPULID.E THE CRANE FLEES 51
102. Wings with Sc? close to tip of Sc„ the two veins thus being subequal
in length or nearly so. (Gonomyaria) Gnophomyia Osten Sacken
"Wings with Sc2 far removed from tip of Sc, the latter vein long, sub- equal in length to Rs; temperate. (Eriopteraria) . . . .Ormosia Rondani
103. Wings with Rs ending in cell Rs, there being no element R2+3+4 (41)
(Eriopteraria) Molophilus Curtis
Wings with Rs ending in cell Rt, cell R3 being petiolate by a distinct element R=.3.4 (42-44) 104
104. Wings with a supernumerary crossvein in cell R3; vein 2nd A strongly
bisinuate (42). (Eriopteraria) Helobia St. Fargeau
Wings without a supernumerary crossvein in cell R3; vein 2nd A straight or simply sinuous (43, 44) 105
105. Wings with veins R3 and R4 divergent, unequal in length, R3 being
less than two-thirds R^, cell R3 at margin much more extensive than
cell R. IOC
Wings with veins R3 and R4 nearly equal in length, or with R3 ex- ceeding three-fourths of the length of R4, the veins extending gener- ally parallel to one another to the margin; cell Rj at margin wider than cell R3 107
106. Wings with veins R3 and R, very unequal in length, widely divergent
or sprawly, R3 being only about one-fourth R4 and ending in costa close to vein R1+2; cell R3 at margin some eight times as wide as
cell R-; tropical Neognophomyia Alexander
Wings with veins R3 and R4 less conspicuously unequal, R3 being about one-half R,; cell Rs at margin some three or four times as wide as cell R-; tropical and subtropical. (Gonomyia).
Gonomyia: Progonomyia Alexander
107. Antennte of both sexes with the flagellar segments more or less kid-
ney-shaped to give a nodulose appearance to the organ; large species (wing, 15 mm. or more); tropical. (Sigmatomeraria).
Sigmatomera Osten Sacken Antennae of both sexes simple or nearly so, not nodulose; smaller (wing less than 12 mm., usually less than 10 mm.) 108
108. Cox« of middle and hind legs only slightly separated by the small
meral region; wings with Sci relatively short, not exceeding one- third the length of Rs 109
Coxae of middle and hind legs widely separated by a large "pot- bellied" meral region; wings with Sci very long, exceeding one-half the length of Rs. (Eriopteraria) 110
109. Wings with Rs in alignment with R2+3+4; Sc short, Sc, ending opposite
the fork of Rs and far before R-..; Sci and Sc2 subequal; male hypo- pygium with interbasal structures conspicuously developed as
blackened spines; temperate Lipsothrix Loew
Wings with Rs in approximate alignment with R.,; Sc long, Sc, ending opposite or shortly before R:, at or beyond midlength of R1.+S+4; Sc, much longer than Sc: (43); male hypopygium without evident interbases Gnophomyia Osten Sacken
110. Wings with R^ far before fork of R2+3+4, at or just beyond the fork of
Rs; male with a very large hairy stigmal region that more or less distorts the adjoining veins; western plains.. Empedomorpha Alexander Wings with R- beyond the fork of R2+3+4; stigma nonnal Ill
52 NORTH AMERICAN DIPTERA
111. Wings with vein Cui nearly straight, its distal section not swinging
cephalad toward wing-tip; cell 1st M; small, less than one-half the distal section of M1+2; terminal three segments of antennae smaller
than the remainder of flagellum Trimicra Osten Sacken
Wings with vein Cui having its distal section slightly deflected at apex toward wing-tip; cell 1st M.., when present, elongate, subequal to or longer than the distal section of M1+2; flagellar segments becoming progressively smaller to outer end (44) (Erioptera) 112
112. Wings with vein 2nd A arcuated so cell 1st A at midlength is as
broad as, or broader than it is at margin; cell 1st M: opening into cell 2nd M- by atrophy of m; (44); chiefly temperate.
Erioptera: Erioptera Meigei' Wings with anal veins divergent, cell 1st A being widest at margin; cell 1st M2 generally closed 113
113. Wings with cell 1st M. open 114
Wings with cell 1st M2 closed, the basal section of M3 greatly ex- ceeding m in length 115
114. Wings with cell 1st Mj opening into cell M3 by atrophy of basal sec-
tion of Ms; where closed, the elements closing outer end not greatly disproportionate in length, m being one-half or more of M3; chiefly
tropical Erioptera: Mesocyphiona Osten Sacken
Wings with cell 1st M2 opening into cell 2nd M2 by atrophy of m; northern and western Erioptera: Psiloconopa Zetterstedt
115. Wings with a spur from the basal section of vein M3, jutting basad
into cell 1st M2 Erioptera: Hoplolabis Osten Sacken
Wings with no such spur as described Erioptera: Ilisia Rondani
SUPPLEMENTARY KEY TO THE SUBAPTEROUS TIPULID^
1. Frontal prolongation of head with nasus (Tipulinse) Tipula Linnjeus
Frontal prolongation of head (or rostrum) without nasus 2
2. Eyes with numerous short erect setai between ommatidia (Pediciini).
Tricyphona Zetterstedt Eyes without setae 3
3. Tibial spurs present. (Hexatomini) Limnophila Macouart
Tibial spurs lacking. (Eriopteriui) Chionea Dalman
TYPE SPECIES OF THE NEW GENERA AND SUBGENERA PROPOSED
Dicranota: Eudicranota; type, Dicranota notabilis Alexander. Dicranota: Paradicranota; type, Dicranota rivularis Osten Sacken. Archilimnophila; type, Limnophila unica Osten Sacken. Limnophila: Idiolimnophila; type, Limnophila emmelina Alexander.
FAMILY TIPULID.E — THE CRANE FLIES 53
BIBLIOGRAPHY OF IMMATURE STAGES
Alexander, C. P.
1920. The crane-Hies of New York. Part II. Biology and Phylogeny.
Cornell Univ. Agric. Expt. Sta. Mem. 38; pp. 691-1133, 87 pis.
(bibliography to 1920). 1931. Deutsche Limnologische Sunda-Expedition. The Crane-flies.
Archiv fiir Hydrobiologie, Suppl. Bd. IX, Tropische Binnenge-
wasser, 2; pp. 135-191, 51 figs., 1 pi. (bibliography of biology,
1920-30).
Rogers, J. S.
1933. The ecological distribution of the crane flies of northern Florida. Ecological Men., 3, No. 1, pp. 1-74, figs. 1-25.
BIBLIOGRAPHY OF KEYS TO SPECIES OF NORTH AMERICAN
TIPULID^
The genera of which Keys are given follow the reference and the regions covered are indicated: Neo., Neotropical; Nea., Nearctic.
Alexander, C. P.
1912a. On the tropical American Rhipidise. Bull. Brooklyn Ent. Soc, VIII, pp. 6-17, 1 pi. (Limonia: Rhipidia, Neo.). 1912b. A revision of the genus Brachypremna Osten Sacken. Journ. New York Ent. Soc, XX, pp. 225-236, 1 pi. ( Brachypremna ) . 1912c. New species of Furcomyia. Canadian Ent., XLIV, pp. 333-334.
(Limonia: Dicranomyia, Neo., in part). 1913a. New Neotropical Antochini. Psyche, XX, pp. 40-54, 1 pi.
(Orimarga; Toxorhina, Neo.). 1913b. A synopsis of part of the Neotropical crane-flies of the subfamilv Limnobinse. Proc. United States Nat. Mus., XLIV, pp. 481-549, 4 pis. (Epiphragma; Polymera; Lecteria; Trentepohlia; Gonomyia; Gnophomyia; Cryptolabis; Molophilus; Erioptera; 3Iesocy- phona, Neo.). 1913c. The Neotropical Tipulidae in the Hungarian National Museum. I, II. Ent. News, XXIV, pp. 404-412, 439-449. (Limonia: Peripheroptera; Teucholabis: Paratriopesa). 1914a. New or little-known Neotropical Hexatomini. Psyche, XXI, pp. 33-45, 1 pi. (Hexatoma: Eriocera, Penthoptera, Neo.). 1914b. A revision of the American species of Tanypremna Osten Sacken and Megistocera Wiedemann. Jouin. New York Ent. Soc, XXII, pp. 205-218, 1 pi. (Tanypremna). 1914c. On a collection of crane-flies from British Guiana. Trans. Ameri- can Ent. Soc, XL, pp. 223-255, 2 pis. (Psaronius; Trentepohlia, part; Sigmatomera; Teucholabis: Teuch- olabis; Gonomyia: Lipophleps, part, Neo.). 1915. Two new crane-flies from Porto Rico. Insec. inscit. Menst., Ill, pp. 104-107. (Hexatoma: Eriocera, part).
54 NORTH AMERICAN DIPTERA
Alexander, C. P. (Continued)
1916a. New Limnophiline Crane-flies from the United States and Canada. Journ. New York Ent. See, XXIV, pp. 118-125, 1 pi. (Limnophila: Prionolabis, part: Nea.) 1916b. New species of Crane-flies from the West Indies. Ent. News, XXVII, pp. 343-347, 6 fig-s. (Hexatoma: Eriocera). 1916c. New or little-known crane-flies from the United States and Can- ada. Part 3. Proc. Acad. Nat. Sci, Philadelphia, 1916, pp. 486- 549, 7 pis. (Dicranota: Rhaphidolabis; Gonomyia, Nea.). 1917. New Nearctic crane-flies. Part 3. Canadian Ent., XLIX, pp. 199-211. (Erioptera: Empeda, Nea.). 1919a. Notes on the genus Dicranoptycha Osten Sacken. Ent. News, XXX, pp. 19-22. (Dicranoptycha). 1919b. Records and descriptions of Neotropical craneflies. Journ. New York Ent. Soc, XXVII, pp. 132-154, 1 pi. (Trentepohlia, part; Gnophomyia, s.L). 1919c. The crane-flies of New York. Part I. Distribution and taxonomy of the adult flies. Cornell Univ. Agr. Expt. Sta., Mem. 25; 765-993, 55 pis. (Tanyptera; Ctenophora; Nephrotoma; Tipula; Dolichopeza; Oro- peza; Phalacrocera; Cylindrotoma; Limonia: Dicranomyia, Rhi- pidia, Geranomyia, Limonia; Helius; Dicranoptycha; Pedicia: Pedicia, Tricyphona; Dicranota: Dicranota, Rhaphidolabis; Ula; Adelphomyia; Epiphragma; Limnophila, s.L; Eriocera; Chionea; Cladura; Gonomyia; Teucholabis; Rhabdomastix; Molophilus; Ormosia; Erioptera; Toxorhina). 1920a, Undescribed Tipulidae from western North America. Proc. Cali- fornia Acad. Sci., (4), X, pp. 35-46. (Ulomorpha). 1920b. New or little-known crane-flies from tropical America. Canad. Ent., LII, pp. 141-144. (Polymera, part, Neo.). 1926a. Studies on the crane-flies of Mexico. Part II. Ann. Ent. Soc. America, XIX, pp. 158-179, 2 pis. (Atarba; Nea., Neo.). 1926b. Undescribed species of crane-flies from Cuba ar.:l Jamaica. Journ. New York Ent. Soc, XXXIV, pp. 223-230. (Gonomyia, part, Neo.). 1927. Undescribed species of the genus Limnophila from eastern North America. Part II. Bull. Brooklyn Ent. Soc. XXII, pp. 56-64. (Limnophila: Elseophila)
1929. The crane-flies .of New York: Fourth Supplementary List. Bull.
Brooklyn Ent. Soc, XXIV, pp. 295-302. (Pedicia, Nea.)
1930. The genus Sigmatomera Osten Sacken, — with observations on the
biology by Raymond C. Shannon. Encycl. Entomol., Diptera, V, pp." 1-8, 8 figs. (Sigmatomera).
FAMILY TIPULID.E THE CRANE FLIES
55
Dietz, W. G.
1913. A synopsis of the described North American species of the Dip-
terous g-enus Tipula L. Ann. Ent. Soc. America, VI, pp. 461- 484. (Tipula, Nea.).
1914. The hebes group of the Dipterous genus Tipula Linnseus. Trans.
American Ent. Soc, XL, pp. 345-363, 2 pis. (Tipula, part; Nea.) 19L6. Synoptical table of the North American species of Ormosia Rondani (Rhypholophus Kolenati), with descriptions of new species. Trans. American Ent. Soc, XLVII, pp. 135-146, 1 pi. (Ormosia, Nea.).
1917. Key to the North American species of the tricolor group of
the Dipterous genus Tipula Linnaeus. Ent. News, XXVIII, pp. 145-151, 1 pi. (Tipula, part; Nea.).
1918. A revision of the North American species of the Tipulid genus
Pachyrhina Macquart, with descriptions of new species. Trans. American Ent. Soc, XLIV, pp. 105-140, 4 pis. (Nephrotoma, Nea.).
1919. The streptocera group of the Dipterous genus Tipula Linnaeus.
Ann. Ent. Soc. America, XII, pp. 85-94, 1 pi. (Tipula, part; Nea.). 1921a. The impudica group of the Dipterous genus Tipula Linnaeus. Ann. Ent. Soc America, XIV, pp. 1-15, 1 pi. (Tipula, part; Nea.). 1921b. Description of two new species of the angustipennis group of the Dipterous genus Tipula Linnaeus, with table of species. Ent. News, XXXII, pp. 299-302. (Tipula, part; Nea.).
Doane, R. W.
1908a. Notes on the Tipulid genus Dicranomyia. Ent. News, XIX, pp. 5-9. (Limonia: Dicranomyia, Nea.). 1908b. New North American Pachyrhina, with a table for determining the species. Ent. News, XIX, pp. 173-179. (Nephrotoma, Nea.). 1908c. New species of the Tipulid genus Rhypholophus, with a table for determining the North American species. Ent. News, XIX, pp. 200-202. (Ormosia, Nea.).
Garrett, C. B. D.
1922. New Tipulidae from British Columbia. Proc Ent. Soc. Wash- ington, XXIV, pp. 58-64, 13 figs. (Limonia: Alexandriaria, Nea.)
Hine, J. S.
1903. The genus Peditia, with one new species. Ohio Nat., Ill, pp. 416-417. (Pedieia, Nea.)
56 NORTH AMERICAN DIPTERA
Johnson, C. W.
1909. New and little known Tipulidse. Proc. Boston Soc. Nat. Hist., XXXIV, pp. 115-135, 2 pis. (Dolichopeza: Oropeza, Nea.)
Osten Sacken, C. R.
1869. Diptera of North America, Part 4. Smithson. Miscel. Coll. 219, pp. 1-345, 4 pis., 7 figs. (Limonia: Geranomyia, Dicranomyia, Rhipidia, Limonia; Pedicia: Tricyphona; Limnophila; Eriocera; Gonomyia; Ormosia; Erioptera). 1886. Biologia Centrali-Americana. Iiisecta, Diptera, I, pp. 1-216, 3 pis. (Nephrotoma; Hexatoma: Eriocera, Neo.)
GENERAL BIBLIOGRAPHY OF MORPHOLOGICAL TERMS OF ESPECIAL VALUE IN A STUDY OF THE TIPULID^.
Alexander, C. P.
1927. The interpretation of the radial field of the wing in the Nema-
tocerous Diptera, with special reference to the Tipulidae. Proc.
Linn. Soc. New South Wales, LII, pp. 42-72, 92 figs. 1929. A comparison of the systems of nomenclature that have been
applied to the radial field of the wing in the Diptera. IVth
Internat. Congress Ent., Trans., II, pp. 700-707, 3 pis.
Cole, F. R.
1927. A study of the terminal abdominal structures of the male Dip-
tera. Proc. California Acad. Sci., (4), XVI, pp. 397-499, 287 figs.
Crampton, G. C.
1923a. The genitalia of male Diptera and Mecoptera compared with
those of related insects, from the standpoint of phylogeny.
Trans. American Ent. Soc, XLVIII, pp. 207-225, 3 pis. 1923b. Preliminary note on the terminology applied to the parts of an
insect's leg. Canadian Ent., LV, pp. 126-132, 1 pi.
1925. Evidences of relationship indicated by the thoracic sclerites of
certain Eriopterine Tipuloid Diptera. Insec. Inscit, Menst., XIII, pp. 197-213, 2 pis.
1926. The external anatomy of the primitive Tanyderid Dipteran Macro-
chile spectrum Loew, preserved in Baltic Amber. Bull. Brook- lyn Ent. Soc, XXI, pp. 1-14, 2 pis.
1928. The eulabium, mentum, submentum and gular region of insects.
Journ. Ent. and Zool., XX, pp. 1-18, 3 pis. 1931. A phylogenetic study of the posterior metathoracic and basal ab- dominal structures of insects, with particular reference to the Holometabola. Journ. New York Ent. Soc, XXXIX, pp. 323- 357, 4 pis.
Snodgrass, R. E.
1903. The terminal abdominal segments of female Tipulidge. Journ.
New York Ent. Soc, XI, pp. 177-183, 2 pis.
1904. The hypopygium of the Tipulitlse. Trans. American Ent. Soc,
XXX, pp". 179-236, 11 pis.
FAMILY TIPULID.E THE CRANE FLEES 57
SYSTEMATIC ARRANGEMENT OF GENERA AND SUBGENERA, WITH CITATIONS TO THE ABOVE BIBLIOGRAPHY OF KEYS
TipulinsB
Ctenophora (Alexander, 1919c)
Tanyptera (Alexander, 1919c)
Nephrotoma (Alexander, 1919c; Dietz, 1918; Doane, 1908b; Osten Sacken,
1886.) Tipula, s.l. (Alexander, 1919c; Dietz, 1913, 1914, 1917, 1919, 1921a,
1921b.) Brachypremna (Alexander, 1912b) Tanypremna (Alexander, 1914b) Dolichopeza: Oropeza (Alexander, 1919c; Johnson, 1909)
Cylindrotominae
Phalacrocera (Alexander, 1919c) Cylindrotoma (Alexander, 1919c)
Limoniinse Limoniini
Limonia: Limonia (Alexander, 1919c; Osten Sacken, 1869)
Dicranomvia (Alexander, 1912c, 1919c; Doane, 1908a;
Osten Sacken, 1869) Alexandriaria (Garrett, 1922) Peripheroptera (Alexander, 1913c)
Rhipidia (Alexander, 1912a, 1919c; Osten Sacken, 1869) Geranomyia (Alexander, 1919c; Osten Sacken, 1869) Orimarga: Orimaroa (Alexander, 1913a) Dicranoptycha (Alexander, 1919a, 1919c) Helius (Alexander, 1919c)
Pediciini
Pedicia: Pedicia (Alexander, 1919c, 1929; Hine, 1903)
Tricyphona (Alexander, 1919c; Osten Sacken, 1869) Dicranota: Dicranota (Alexander, 1919c)
Rhaphidolabis (Alexander, 1916c, 1919c)
Plectromyia (Alexander, 1919c) Ula (Alexander, 1919c)
Hexatomini
Adelphomyia (Alexander, 1919c)
Epiphrasma (Alexander, 1913b, 1919c)
Polymera (Alexander, 1913b, 1920b)
Dactylolabis (Alexander, 1919c; Osten Sacken, 1869)
Pseudolimnophila (Alexander, 1919c)
Limnophila, s.l. (Alexander, 1919c; Osten Sacken, 1869)
Prionolabis (Alexander, 1916a, 1919c; Osten Sacken, 1869)
Eutonia (Alexander, 1919c)
Lasiomastix (Alexander, 1919c; Osten Sacken, 1869)
Phylidorea (Alexander, 1919c)
Ela-ophila (Alexander, 1919c, 1927; Osten Sacken, 1869)
Idioptera (Alexander, 1919c)
Dicranophragma (Alexander, 1919c) Pilaria (Alexander, 1919c) Ulomorpha (Alexander, 1920a)
58 KORTH AMERICAN DIPTERA
Psaronius (Alexander, 1914c)
Hexatoma: Eriocera (Alexander, 1914a, 1915, 1916b, 1919c;
Osten Sacken, 1869, 1886) Penthoptera (Alexander, 1914a) Atarba: Atarba (Alexander, 1926a)
Eriopterini
Chionea (Alexander, 1919c)
Cladura, s.l. (Alexander, 1919c)
Lecteria (Alexander, 1913b)
Sigmatomera (Alexander, 1914c, 1930)
Trentepohlia: Paramongoma (Alexander, 1913b, 1914c, 1919b)
Teucholabis: Teucholabis (Alexander, 1914c, 1919c)
Paratropesa (Alexander, 1913c) Gonomyia, s.l. (Alexander, 1916c, 1919c; Osten Sacken, 1869)
Progonomyia (Alexander, 1916c)
Lipophleps (Alexander, 1914c, 1916c, 1919c)
Gonomyia (Alexander, 1913b, 1916c, 1919c, 1926b; Osten Sacken,
1869)
Ptilostena (Alexander, 1916c) Gnophomyia, s.l. (Alexander, 1913b, 1919b) Rhabdomastix: Sacandaga (Alexander, 1919c) Erioptera, s.l. (Alexander, 1919c; Osten Sacken, 1869)
Erioptera (Alexander, 1919c; Osten Sacken, 1869)
Mesocyphona (Alexander, 1913b, 1919c; Osten Sacken, 1869)
Ilisia (Alexander, 1919c)
Empeda (Alexander, 1917, 1919c) Cryptolabis (Alexander, 1913b) Ormosia (Alexander, 1919c; Dietz, 1916; Doane, 1908c; Osten Sacken,
1869) Molophilus (Alexander, 1913c, 1919c) Toxorhina: Toxorhina (Alexander, 1913a, 1919c)
59
Family Anisopodidse
Moderately small, elongate flies with long legs and three ocelli.
Head siibspherical or hemispherical, the eyes of the males holoptie or dichoptic, usually rounded. Proboscis moderately prominent, with small labella; palpi long, four segmented. Antennae usually about as long as the thorax, cylindrical, composed of twelve to sixteen segments. Thorax convex, without distinct transverse suture; scutellum semi- circular, short and broad, the metanotum well developed. Abdomen more or less cylindrical, flattened below, the genitalia small. Legs slender, without spines; anterior coxae and the basal segment of the tarsi elongated; tibiae with or without apical spurs; pulvilli absent, the empodia pad-like. Wings rather large, lying flat on the abdomen when at rest; auxiliary vein present; radius with 3 or 4 {Axymyia, Fig. 15*) branches; cell 1st M, closed or open (Figs. 14, 16*); a single anal vein reaches the margin.
The adults are frequently common, particularly those belonging to the genus Anisoptis which sometimes occur in small swarms near the edges of woods in the vicinity of swamps and also on the trunks of trees. The other genera occur in moist places, particularly upon foliage. The members of this family, insofar as known, breed in wet or moist decaying organic matter, as fermenting sap, rotten wood and similar situations.
There are about 80 described species, distributed in 6 genera and 3 subfamilies, all of the latter being found in the North American fauna.
Plate n, Tipuloidea.
Fig. 1, Anisopus species. Fig. 2. Olbiogaster species.
60 NORTH AMERICAN DIPTERA
KEY TO GENERA
1. Wings with cell 1st M2 present. (Anisopodinse) 2
Wings with cell 1st M; open by the atrophy of basal section of M3 3
2. Wing-membrane with macrotrichia (14*; also 1); posterior tibia with a
comb of spinous setae Anisopus Meigen
Wing-membrane without macrotrichia; posterior tibia without spinous comb; tropical (2) Olbiogaster Osten Sacken
3. Wings with vein R3 present as a nearly transverse element, connecting
with vein R1+2 at margin (15*); eastern (Axymyiinse) . .Axymyia McAtee Wings with vein R3 lost by atrophy, there being only two branches of Rs (16*) ; north temperate (Mycetobiinje) Myeetobia Meigen
The most important paper:
Edwards, F. W.
1928. Diptera. Fam. Protorhyphidse, Anisopodidse, Pachyneurida;, Tri- choceridse. Genera Insectoruni, Fasc. 190, pp. 1-41, 2 pis.
* Plate II, Tipuloidea.
61
Family Blephariceridse — The Net-Winged Midges
Affathon elesantula.
Moderate sized, elongate, nearly l:)are species with long legs and rather wide, delicate wings.
Eyes sometimes lioloptic in one or both sexes and usnally bisected below the middle by a narrow, nnfaeeted line below which the facets are smaller; three ocelli present. Antenna slender, composed of nine to fifteen segments and clothed witli pnbescence. Month i)arts more or less elongate, the femak^s with slender, flattened elongate serrate man- dibles. Mosontum with distinct, broadly interrupted transverse suture. Legs rather slender, the posterior pair longer than the others; tibia) with or without spurs; pulvilli and empodium absent or nearly so. Wings broad, bare, the anal angle projecting, almost always with a net- work of delicate lines due to the creasing of the folded wings in the pupal case.
The adults are not common in most col k'ct ions but are often found in large numbers near fast-flowing streams. I have found them chiefly on the foliage of evergreens or on the sides of cliffs or rocks.
62
NORTH AMERICAN DIPTERA
The larvffi live in swift water, clinging to the rocks or stream bed by a series of ventral suckers, pupation taking place in the stream. The immature stages are even more easily identified than the adults. The latest revision of the family is contained in Williston's Manual of North American Diptcra, 3rd edition.
KEY TO GENERA
1. An incomplete longitudinal vein between the fourth and fifth longi-
tudinals (1) 3
No incomplete vein between these veins (2) 2
2. Proboscis long; palpi but little developed (2, 5) Paltostoma Schiner
Proboscis not longer than the vertical diameter of the head; palpi well
developed, four-segmented Kelloggina Williston
3. Second basal cell closed apically 4
Second basal cell open apically (1) Blepharicera Macquart
4. Second longitudinal vein branched, the branch either simulating a cross-
vein near the base of the second vein, or elongate 5
Second vein not branched (3) Philorus Kellogg
5. Pleura pilose or haired (4) *Bibiocephala Osten Sacken
Pleura bare Agathon Roder
* Bibionus Curian is a synonym but the two species upon which the genera were based are distinct.
Blephariceridai. — 1 . Blepharicera ; cephala; 5, Paltostoma argyrocincta.
Paltostoma ;
Philorus; 4, Bibio-
63
Family Simuliidae — The Black Flies
Larva of Simulium venustum showing- the mouth fans (left) used for securing food. (After Metcalf and Sander- son).
Small, usually dark colored flies, rarely over 5 mm. in length, wiili short, thick legs.
Head rather hemispherical; face short, eyes round or reniform, holoptic in the males; ocelli absent. Proboscis rather short, with small, horny labella?, palpi incurved, four segmented, the basal segment short, tlie two following of etiual length, the fourth longer and more slender than the preceding. Thorax arched, without transverse suture; scutel- lum small. Abdomen rather cylindrical, tapering in the males, composed of seven or eight segments; genitalia concealed. Legs short and strong, the femora broad and flat; tibia? usually with terminal spurs; basal segment of the tarsi elongate, the apical segment small. Wings large and broad, Avith distinct allula", the anterior veins thickened, the others weak. Auxiliary vein ending in the costa near the middle of the wung, the second vein absent, the first and third approximate; anterior cross- vein very short; fourth vein curved, forked nearly opposite the anterior cross-vein, the branches terminating near the apex of the wnng.
The Black-Flies, Buffalo Gnats, Turkey (Inats, to use some of the common names for these pests, need no introduction to the hunter or fisherman. To most people they are extremely annoying and as they frequently occur in enormous numbers in the neighborhood of streams fishermen are only too well acquainted with them. As a rule their bites do not attract immediate attention but after a short time they cause painful swellings and, if in sufficient numbers, may result in the serious illness of the sufferer and even death. The adults attack all warm blooded animals and are known from all parts of the world, being par- ticularly abundant in the north temperate and subarctic zones.
64
NORTFI AMERICAN DIPTERA
In addition to the irritation caused by their bites some members of the family carry disease. In Africa OncJwcerciasis, a disease caused by a worm {Onchocerca volvulus Leuckart) of the family Filariida? is transmitted by EiisimuUum damnomm Theobald. In man the disease takes the form of small to rather large, subcutaneous swellings and may or may not be apparent without careful examination. From 40 to 50 per cent of the natives of Sierra Leone were said by Blacklock to be infected in 1926.*
* Ann. Trop. Med. & Parasit., xx. pp. 1-48. 203-218.
I I ^ I f
W W
b
J
(a) pupa of Simulium venustum in pupal cocoon and (b) pupa of S. bracteatum, with cocoon removed. (After Metcalf and Sanderson).
• FAMILY SIMULIID.E THE BLACK FLIES 65
In Central America three species of Swiulium have been shown to carry a disease disphiying various symptoms and sometimes resulting in blindness. Tlie causative agent is related to the form described above and was named Onchocerca cmcutinis by Brumpt. In some cases of infection there are no clinical symptoms but in others there are erysipelas-like swellings, the name coastal erysipelas being applied to the disease in such cases. Nodular swellings may occur on the head, shoulder blades, ribs iliac crests, etc. In the eye the microfilariae may cause conjunctivitis, Jicratitis and iritis, blindness sometimes resulting.
Both the fly and man are necessary for the development of the disease. After being ingested by the fly the microfilariae pass from the intestine to the muscles of the thorax where further development takes place. The infective stages occur in the proboscis of the fly and are transferred to man during feeding by the insect. Strong has discussed Onchocerciasis in Guatemala.*
The larvffi live in streams w-here they attach themselves to stones, l)lants, etc. and collect their food from the flowing water. Pupation takes place wdthin the larval cocoon, the adults emerging under water and, quickly reaching the surface, fly away. Under favorable condi- tions many thousands of larvce may be found together, being so numer- ous as to entirely conceal the surface to which they are attached.
The latest revision of the North American species is by Dyar and Shannon. t Unfortunately these authors apparently took greater pains to find fault with the work of others than to clarify their own con- clusions and only a study of their material and amplification of the descriptions will result in a clear understanding of the specific limits. In some cases the drawings were evidently made from freshly prepared slides and these show characters which gradually disappear, with the result that the same characters cannot be found in old slides and may not even be present in freshly prepared ones made from old specimens. Just what effect this will have on the validity of several of the forms recognized by the authors it is impossible to say. Malloch:}: has also revised the familv : the two contributions should l)e used together.
* 1931, Science. N. S.. Ixxiii, pp. 593-594.
t 1927, Dyar and Shannon, Proc. U. S. N. M., Ixix. Art. 10, pp. 1-54, 7 plates.
t 1914, Malloch, Bull. U. S. Dept. of Agric. Bur. Ent., Tech. Ser., No. 26.
66
NORTH AMERICAN DIPTERA
KEY TO GENERA
1. Third vein forked 3
Third vein simple 2
2. Petiole of the second and third veins setulose above . . . Eusimulium Roubaud Petiole of the second and third veins bare (1) Simulium Latreille
3. Fifth vein not forked (3) Parasimulium Malloch
Fifth vein forked (2) Prosimulium Roubaud
Simuliidse. — 1, Simulium; 2, Prosimulium; 3, Parasimulium
()7
Family Thaumaleidae
Thaumalea species.
Small, bare, obscurely reddish yellow or brownish flies of peculiar appearance.
Head small, round; eyes holoptic in both sexes; ocelli absent; proboscis short; palpi longer than the antenna?, composed of five seg- ments, the first short, the second thickest; antenna^ situated near the oral margin, comi)Osed of a scape, i)edicel and flagellum, the latter very comi)act and arista-like, but composed of ten distinct segments, the l)asal two rather large and globose. Thorax robust, strongly convex, without transverse suture, somewhat depressed before the rather large, ol)tusely triangular scutellum; metanotum arched. Abdomen narrower than the thorax, cylindrical, composed of seven segments; male genitalia large, the basal piece swollen, bladder-like; ovipositor with broad, rounded lamcllas. Legs simple, comparatively short; coxt^ short; tibiae without spurs; tarsi of moderate length, the anterior pair about as long as the tibicT, the penultimate segment short; empodia vestigial; claws small. Wings longer than the abdomen; auxiliary vein short, terminating in the costa; second longitudinal vein curved; the third and fourth veins simple; basal cell short; anal angle rounded.
There are about three dozen described species belonging to this family, most of them occurring in the Old World. The adults are found along the edges of streams, particularly those with mossy banks, and are not common in collections. They are small flies, under 6 mm. in length, and the wings bend sharply near the base in death, folding downward as in the Psychodidffi.
The larvffi, which resemble those of the Chironomidae, are found in small brooks and streams where the clear water flows very thinly over the rocks, so that the back of the larva is always exposed above the surface. They feed on detritus and diatomes. and move about in search
68 NORTH AMERICAN DIPTERA
of food. The pupje are found in the bottom of the stream between stones, etc.
The following key will separate the described genera, tw^o of which occur in America. The family has been revised by Edwards.*
KEY TO GENERA
1. Subcostal vein ending in the costa or first vein 2
Subcostal vein obsolete apically, ending free. (North America, pluvialis
Dyar & Shannon) Trichothaumalea Edwards
2. Subcostal vein ending in the first vein, very short (Australia, N. Zea-
land, S. America) Austrothaumalea Tonnoir
Subcoastal vein ending in the costa 3
3. Basal segment of c palpi greatly swollen, the second and third segments
not much longer than broad; subcosta weak apically (Europe).
Androprosopa Mile Palpi rather stout, alike in both sexes, somewhat longer than the an- tennas (N. America, Europe) Thaumalea Ruthe
North American Species of Thaumalea
1. Thorax and abdomen brown or blackish 2
Thorax reddish yellow, the abdomen brown elnora Dyar & Shannon
2, Male clasper with two terminal claws americana Bezzi
Male clasper with about six terminal claws johannis Dyar & Shannon
* Edwards, 1929. Zool. Anzeiger, pp. 121-142.
69
Family Chironomidse — The Midges
Small, slender flies, rai-ely over 10 mm. in length, thorax large, the legs slender, antennae of males plumose.
Head small, more or less spherical, partly concealed from dorsal view by the projecting thorax. Antenna} slender, with five to fourteen segments, the basal segment enlarged and globular, plumose in the males, more or less haired in the females. Eyes reniform or oval, the ocelli al)sent or rudimentary. Proboscis short, not adapted for piercing; palpi with three or four segments. Thorax sub-ovate, or moderately long, more or less projecting in front, without a transverse suture l)ut with a wide, longitudinal impression in front of tlie scutellum; metanotum with a more or less distinct longitudinal groove in the middle; scutellum small and hemispherical. Legs slender and rather long, especially the front pair; the tarsi often very long; empodium and pulvilli present or absent. Wings bare or haired, long and narrow, usually with a strong anal angle; anterior veins strong; auxiliary vein complete though slender; second longitudinal vein weak or absent, the third vein often forked and connected with the first by a crossvein; fourth vein often Avith two branches which may or may not be petiolate basally, the fifth vein usually furcate; second basal cell open or closed apically; costa usually ending at the termination of the third vein, usually well before the tip of the wing. Abdomen narrow and long, especially in the males, shorter and more robust in the females, the hypopygium exposed; ovi- positor short.
The Certatopogonidffi, formerly included in this family by most authors, have been recognized as a distinct family by JMalloch and Ed- wards, and are so treated here. They may be distinguished l3y the shape of the thorax and absence of the metanotal depression.
The midges bear little resemblance to mosquitoes when viewed by a careful observer, but to the layman they show no differences and are not differentiated. Many people believe that they are "young" mos- cpiitoes and that they will "grow up", but there is, of course, no justifi- cation for such a belief. In mosquitoes the costa extends entirely around the wing and the wing veins and costa are usually scaled.
The family is a very large one and comprises close to two thousand described species. Midges are found almost everywhere, but since the larvae are aquatic their distribution is limited to the vicinity of water, although they are frequently found in large numbers at a consideral^le distance from any visible water supply. While they are not strong
70 XORTH AMERICAN DIPTERA
fliers tliev can remain in the air for long periods of time and they often occur in large numbers. Williston states that in the Eocky Mountains he has observed them dancing in the air in incredible numbers and pro- ducing a noise like a distant vvaterfall. As a rule they swarm in the evening, but swarms are not uncommon in sheltered places during the day. For the most part only the males swarm, although an occasional female may be found with them. While, as a rule, only one species will be found in a swarm it is not unusual to find other species among them. The females are found mostly on foliage, where they rest on the under surface during the day. Some forms occur commonly on tree trunks, logs, and in grass. They are attracted to light, frequently in very large numbers.
Since many of the Chironomids are very small they must be han- dled with care. The larger ones may be pinned in the usual manner, provided fine pins are used; the smaller should be attached to the side of a pin by a ring of shellac, care being taken to leave one wdng and the tarsi free. Specimens without front tarsi are almost useless and, since the insects dry quickly, they must be mounted within an hour or two.
The larvffi are elongate, cylindrical, slender and curved more or less downward, particularly when preserved. The head and legs are conspicuous and there may be one or more pairs of leg-like pads pos- teriorly. They arc scavengers and live in water everywhere, also in mud and have been dredged from a depth of nearly a thousand feet in Lake Superior. Some are also found in decaying vegetation, in moss, etc. ]\Iany of them are free-living while others make mud cases on stones, leaves and pieces of wood and I have found one undetermined species building almost colorless cases in Sinrofj]/r<i. ]\Iany of the larva? con- tain haemoglobin and are red in color, the name ''blood-worms" being applied to these.
The classification of the family is not entirely satisfactory and characters for the limitation of genera are few. Edwards* has utilized the tibial spurs and combs for the separation of genera, in addition to other characters. However, the classification must be considered as very artificial, although losing nothing on that account. Since the object of taxonomy is the identification of species the means of obtaining the end is not important. IMany papers dealing with the American species have been published since the appearance of Johamisen's monographic revisionf in 1905, by Kieffer, Malloch,^ Johannsen, etc. Some of the more important are listed below.
* 1929. British non-bitinpr midges. Tr. Ent. Soc. London, Dec. 1929. t 1905. New York State Museum Bulletin No. S6. S 1915. Bull. 111. State Lab. Nat. Hist., x. Art. 6.
FAMILY CHIKOXOMID.T: THE MIDGES 71
KEY TO GENERA*
1. Wings functional 2
Wings greatly reduced, strap-like, not more than half as long as the
abilomen (16) Eretmoptera Kellogg
2. Second basal cell open apically 14
Second basal cell closed 3
3. Second vein either present and forked near tip or else indistinct or
absent (Tanypodinse) 4
Second vein not forked apically, simple, and always distinct (Dia- mesinse) 10
4. Costa not produced beyond end of third vein, wing hairy; fourth tarsal
segment linear (Abiabesmyia Johannsen) (11) Pentaneura Philippi
Costa distinctly produced beyond the end of the third vein 5
5. Second vein wanting, the space between first and third veins broad;
wings hairy 6
Second vein present 7
6. Fifth vein with long petiole (7) Trichotanypus Kieffer
Fifth vein without petiole (Linacerus, Paratanypus) (15).
Podonomus Philippi
7. Fourth tarsal segment cordiform; wings bare, branches of fifth vein
either with or without petiole (Coelotanypus) Clinotanypus Kieffer
Fourth tarsal segment not cordiform ; wings hairy or bare 8
8. Fifth vein not petiolate (6) Anatopynia Johannsen
Fifth vein petiolate 9
9. Petiole of fifth vein not one-third as long as the posterior branch;
wings hairy Tanypus Meigen
Petiole of fifth vein at least half as long as posterior branch of this vein; wings bare or hairy (12) Procladius Skuse
10. Posterior crossvein intersecting the petiole of the fifth vein; eyes bare;
fourth tarsal segment cylindrical (14) Prodiamesa Kieffer
Posterior crossvein intersecting the anterior branch of the fifth vein near its base 11
11. Fourth segment of tarsus more or less cordiform, shorter or at least
not longer than the fifth 12
Fourth tarsal segment cylindrical, longer than the fifth.
Syndiamesa Kieffer
12. Eyes finely pubescent; antenna? of male plumose (3) . . . .Diamesa Meigen Eyes bare 13
13. Legs annulate; male antennae not plumose (8) Heptagyia Philippi
Legs not annulate Psilodiamesa Kieffer
14. Terminal segment (style) of hypopygium of male directed rigidly back-
wards; basal segment of anterior tarsi longer than the tibia, the anterior tibia without distinct spur except in Pseudochironomus
( Chironominse ) 25
Terminal segment of hypopygium folded inwards; first segment of anterior tarsus shorter than the tibia; anterior tibia with spur (Ortho- cladiinje) 15
* Checked by Dr. O. A. Johannsen.
72
NORTH AMERICAN DIPTERA
Chiionomidfe.— 1. Pentapedilum, hairs omitted; 2. Tanytarsus; 3. Diamesa; 4. Crictopus insolitus; o, Chironoitius ; 6, Anatopynia; 7, Trichotanypus; 8, Heptagyia ; 9, Corynoneura; 10, Orthocladius; 11, Pentancura algens; 12, Procladius; 13, Metriocnemus ; 14, Piodiamesa; 15, Podonomus; 16, Eretmoptera.
FAMILY CHIRONOMID-i: THE MIDGES 73
15. Third vein fused with the costa and not reaching beyond the apical
three-fourths of the wing-; a false vein running close to anterior
margin of wing (9 ) Corynoneura Winnertz
Third vein free, no false vein 16
16. Wings with haii's 17
Wings bare 20
17. The thick crossvein joining the third and fourth vein very long and
appearing as the base of the third vein 18
The crossvein short 19
18. Mesonotum conically produced in front; wings spotted. .Eurycnemus Wulp Mesonotum not produced; wing unicolored Brillia KiefTer
19. Pulvilli absent; wing hairs decumbent (13) Metriocnemus Wulp
Pulvilli present though small; wing hairs suberect (Spaniotoma Ed- wards (10) Orthocladius Wulp
20. Mesonotum with a longitudinal fissure; wings black with white markings
in most species Chasmatonotus Loew
Mesonotum without longitudinal fissure 21
21. Claws cleft; large marine species (Telmatogeton Coquillett, not
Schiner) Paraclunio Kieffer
Claws not cleft 22
22. Palpi porrect, 3 segmentetl (Symbiocladius) Trissocladius Kieffer
Palpi flexible, 4 segmented 23
23. Fourth segment of at least the hind tarsi cordifcrm, shorter than the
fifth (Thalassomyia Johannsen, not Schiner) Cardiocladius Kieffer
Fourth tarsal segment linear 24
24. Dorsocentral hairs minute and decumbent; tibia; usually banded with
white; genitalia in most cases in part pure white (4). . .Crictopus Wulp Dorsocentral hairs larger and suberect; tibise not banded (Spaniotoma Philippi) Edwards, Psectrocladius, Trichocladius, Dactylocladius, Camp- tocladius) (10) ^Orthocladius Wulp
25. Wing disc with hairs at least at tip 26
Wings quite bare, the anterior crossvein distinct and oblique 27
26. Squamte fringed; anterior crossvein distinct and oblique (1).
Pentapedikim Kieffer Squamse quite bare, anterior crossvein longitudinal in position or indis- tinct (2) Tany tarsus Wulp
27. Eyes widely separated, reniform; all tibiae with long conspicuous spurs;
pronotal collar large; basal segment of anterior tarsus not longer
than the tibiae Pseudochironomus Malloch
Eyes with dorsal projection; front tibial spur indistinct or absent; basal segment of anterior tarsus longer than the tibia (5).
Chironomus Meigen
The genus Chirocladius Picado, represented by a species from Costa Rica, and which seems to belong among the Chironominge, is too briefly de- scribed to place in the key.
* Pseudochironomus Malloch, with widely separated reniform eyes and very large pronotal collar, in spite of short basal segment of the anterior tarsi and the tibial spurs, belongs with the next section.
74
NORTH AMERICAN DIPTERA
Family Ceratopog^onidse — The Biting Midges
Culicoides species.
Very small, slender flies, rarely 5 mm. in length.
Head small, spheroidal and rounded behind or hemispherical and flattened behind; ocelli absent or practically so; antenna? slender, usually with fourteen segments and a fifteenth microscopic one, the apical three to five segments lengthened, the basal swollen; mouth parts complete, adapted for biting. Thorax rather oval, shorter than in the Chirono- midffi; pronotum never prominent; metanotum rather rounded, never with a longitudinal groove; scutellum small, hemispherical, usually bearing distinct bristles. Wings of moderate width, folded flat over the back when at rest; second vein absent, fourtli vein generally fur- cate; alula very narrow; squamae never completely fringed. Legs moderately long, the posterior pair longest; femora and tibite sometimes swollen, the former sometimes with spines beneath; pulvilli present or absent. Abdomen elongate; genitalia exposed; ovipositor small.
The Ceratopogonida? may be readily distinguished from the Chirono- mida? by the characters enumerated above. They are minute or quite small flies and are often serious pests, es])ecially along the seashore, in the tropics and along our rivers and lakes, but are not limited in dis- tribution to large bodies of water. The adults are either predaceous or externally parasitic although no real differentiation can be made. The larger species are known to prey upon small insects while the small
FAMILY CERATOPOGONlD.r. THE BITING MIDGES 75
forms suck blood and they have been observed more than onee attached to "mantids" or "walkmg sticks", upon which they feed. Warm blooded animals are freely attacked by representatives of the g^'nera CuUcoides, Lasioheha and Lcptoconops and the tiny creatures sometimes make man miserable by their unceasing attention. They are known commonly as '"punkies" and "no-see-ums", the latter name because of their small size, and they are unwitting jokers since almost any large insect is liable to be blamed for the bites of these lilliputians. They are attracted to light in large numbers and are difficult to keep from houses owing to their small size.
In Africa Cidicoides ansteni is known to be the intermediate host of a parasitic worm {Acanthockeiloneura perstans), a form occurring also in South America, but the worm is not known to cause any specific disease. Further study may link the members of this family with the transmittal of diseases of a specific nature.
The larvas are aquatic or semi-aquatic being found in moist places, in mud, sand, decaying vegetation and in tree-holes. It seems likely that most of the marine species live within the tide-zone and for that reason there is no practical means of control, while those living in decaying vegetation form an equally serious problem. The species living in tree holes are seldom aliundant and the elimination of their breeding places is a simple matter. It is not known whether the larvffi are scavengers or predators and it may l)e that they include ])oth groups.
The insects are difficult to capture and require special care in han- dling. Those whicli bite may ])e captured by placing a bottle over them as they suck blood, but the collector will no doubt find it necessary to exercise great self control during the process owing to the numbers which begin feeding at the same time. Specimens seem best when mounted on the side of a pin but some may be kept in alcohol and mounted on slides. Owing to the delicate nature of the hairs on the wings they are easily abraded and the characteristic wing pattern disappears. For this reason dried specimens should always be preserved. Edwards* has dealt with the British species and his paper will be found invaluable. ]\Iallocht, Johannsent, Root, Hoffman and others have published on the North American forms and a great deal of research is being con- ducted at the present time by the last two mentioned authors. I am indebted to Drs. Johannsen and Root for checking and revising the key to this familv.
* 1926, Trans. Ent. Soc. London, rp. 389-426.
I 1915. Bull. III. state Lab. Nat. Hist., x. Article vi ; id, xi. Article 4.
± 1905, N. Y. State Mus. Bull. itse.
76 NORTH AMERICAN DIPTERA
KEY TO GENERA
1. Empodium as long as claws 2
Empodium very short or absent 3
2. Costa extending to about middle of wing; wings with dense macrotrichia
all over (Euforcipomyia Malloch) (3) Forcipomyia Meigen
Costa extending well beyond middle of wing; macrotrichia sparser, sometimes absent (4) *Atrichopogon Kieffei
3. A fold looking like a simple vein between third and fourth veins; first
and third veins indistinct, more or less fused. (Tersesthes Townsend).
Leptoconops Skuse No vein-like fold between third and fourth veins 4
4. Costa extending to about middle of wing; second radial cell short and
square-ended, first radial cell obliterated; macrotrichia usually dense (Pseudoculicoides Malloch, Isoecacta Garrett) (5) . . . .Dasyhelea Kieffer Costa extending well beyond middle of wing; radial cells usually other- wise 5
5. Humeral pits present and conspicuous; microtrichia of wings distinct;
claws of female small and equal; at least some macrotrichia present.
(^cacta Poey) (9, 10) fCulicoides Latreille
Either humeral pits absent or else microtrichia absent or else claws of female very unequal 6
6. The two radial cells small and equal or one or both of them obliterated;
wings finely punctuate but without distinct microtrichia; legs not
thickened 7
Either second radial cell much longer than broad or else wines with distinct microtrichia or else legs modified 8
7. Wings with at least one dark spot and with some macrotrichia; female
claws unequal (Neoceratopogon Malloch) Alluaudomyia Kieflfer
Wings whitish, without dark markings, and without macrotrichia; female claws equal (8) Ceratopogon Meigen
8. Hind femora noticeably thicker than the others 9
Hind femora not thickened 10
9. Hind femora much thickened and spinose beneath; hind tibiae not
thickened (Ceratolophus Kieffer) (1) Serromyia Meigen
Hind femora not spinose; both hind femora and hind tibiae moderately thickened (7 ) M'onohelea Kieffer
10. First and third veins connected by a crossvein, 2 radial cells 11
First and third veins not connected, one long radial cell 15
11. Front femora spinose beneath 12
Front femora not spinose beneath 13
12. Front femora conspicuously swollen Heteromyia Say
Front femora not conspicuously swollen Palpomyia Meigen
13. The branches of the fourth vein petiolate basally (Hartomyia Malloch).
Stilobezzia Kieffer The branches of the fourth \ein arise at or before the cross vein 14
14. Last segment of front tarsi much swollen (2) Clinohelea Kieffer
Last segment of front tarsi not swollen (6) Johannsenomyia Malloch
* Malloch, 1915, Bull. 111. State Lab. Nat. Hist., x, p. 304 (Ceratopogon). t Hoffman, 192.'i. Anier. Journ. Hygiene, v. pp. 274-301.
FAMILY CERATOPOGOXID.E — THE BITIXG MIDGES
77
15. Branches of fourth vein petiolate basally 16
Branches of fourth vein arise at or before the crossvein 17
16. At least one pair of femora with spines beneath Pseudobezzia Malloch
Femora without spines beneath Parabezzia Malloch
17. Posterior branch of the fourth vein elbowed basally in the female (12).
Stenoxenus Coquillett Posterior branch of fourth vein not elbowed 18
18. At least one pair of femora with spines beneath (11) Bezzia Kieffer
Femora without spines beneath Probezzia KiefFer
CeratopoKonkl.'e. — 1, Serromyia ; 2. Clinohelea ; 3. Forcipomyia; 4. Atrichopogon ; 5, Dasyhelea; 6. Johannsenotn> ia ; 7, Monohelea; 8, Ceratopogon ; '.t, Culicoides, thorax; 10, Culicoides cockcrelli ; 11, Bezzia; 12, Stenoxenus.
78 NORTH AMERICAN DIPTERA
Family Psychodidae — The Moth Flies
Thickly haired, small iiies, rarely exceeding 5 mm. in length, the wings clothed with hairs or scales and folded roof-like over the back.
Head small; ocelli absent. Antenna usually as long as the head and thorax together, the segments usually bead-like and sometimes so densely haired as to appear very thick; composed of from twelve to sixteen segments, the basal segments usually short and cylindrical. Proboscis usually short but more or less elongate and rigid in Flehoto- mus; palpi composed of four segments, hairy. Thorax without trans- verse suture, not very convex; scutellum rounded. Abdomen rather cylindrical, composed of six to eight segments; male genitalia prominent, the female ovipositor usually projecting. Wings large, ovate, often pointed, when at rest lying roof -like over the abdomen, the base being bent at more than a right angle, the veins and border densely haired, the integument often with hairs or scales; veins strong, usually con- cealed by the dense hair; crossveins restricted to the basal third of the wing; two or three of the veins furcate. Legs rather short, elongate in Flehotomus and usually thickly haired.
The adults occur commonly in shady places in the vicinity of water and may often be found in large numbers on dense foliage in swamps, where they crawl about on the under surface of leaves, occa- sionally alighting on the upper surface after a short flight. I have seen them in thousands on tree-trunks after a heavy rain and they are not rare on logs and fallen trees where they walk about in a peculiar, jerky manner or remain perfectly still. One or more species of PsycJwda breeds in drain pipes and they often cause uneasiness by appearing in the bath room. Their presence should incite interest rather than fear as the larvae survive hot water and soap alike, and do no harm. The adults are not common in collections, chiefly because they are so easily damaged. The hairs brush off and they become useless unless unusual care is taken of the specimens. No recent revision of the family has appeared and the synonymy is badly mixed and is not to be trusted. The male genitalia offer excellent characters. There are dozens of species and the family offers an excellent opportiuiity for a thorougli, mono- graphic work.
In America two diseases are known to he carried by species of Flehotoimis. The disease known as Verruga Peruviana, Oroi/a Fever or Carrion's Disease lias been found only in narrow valleys on the western slopes of the Peruvian Andes. Verruga is said not to be serious but Oroj/a Fever (Carrion's Disease), the malignant form, is re- sponsible for many deaths annually. Loeal Leishmaniasis or Fspundia
FAMILY PSYCIIODID.E TPIE MOTH FLIES
79
occurs in South and Central America. The causative organism is Leishmania hrazilicnsis but it is not known definitely which species of Flehotomus carry the disease. It is possible that most of them are capable of doing so. The statement has been made that the adults of Flehotomus are nocturnal and that protection against disease may be obtained by remaining indoors at night. Most of the nocturnal blood- sucking flies may be found on the wing on dull cloudy days.
The larvffi live in decaying vegetable matter, dung, or water and are peculiar in possessing ])oth open spiracles and tracheal gills; the head bears eye-spots; in the aquatic forms there are sucking discs on the segments behind the head, but no feet.
KEY TO GENERA
1. Two longitudinal veins behind the posterior forked vein 2
Three longitudinal veins behind the posterior forked vein 3
2. Two forked veins in front of the middle of the wing.*Flebotomus Rondani One forked vein in front of the middle of the wing (3).. .Maruina Miiller
3. Wings with scales or scale-like hairs on the veins or membrane 4
Wings with hairs only 5
4. Wing membrane with broad scales over most of the surface.
Parabrunettia Brunetti Wings with scales on the veins only Brunettia Annandale
5. Two longitudinal, unforked veins between the anterior and posterior
furcate veins 6
Only one longitudinal vein between the anterior and posterior furcate veins (4) Trichomyia Haliday
6. The second simple vein behind the anterior furcate vein ends in the
tip of the wing ( 1 ) Psychoda Latreille
The second simple vein ends behind the tip of the wing (2).
Pericoma Walker
Phlebotomus of authors.
Psychodidie. — 1, Psychoda;
figures 2-4.
Pericoma; 3, Maruina; 4, Trichomyia. Hairs omitted from
80
NORTH AMERICAN DIPTERA
Family Dixid^
Dixa species.
Eather small, slender, nearly bare species occurring near running water.
Proboscis somewhat projecting; palpi four-segmented; antennas long, the basal segments swollen, the flagellar segments hair-like and poorly separated; ocelli absent; eyes round. Thorax strongly convex, without transverse suture; metanotum arched; scutellum transverse. Abdomen long and slender, composed of seven or eight segments, thick- ened posteriorly in the male, pointed in the female. Legs long and slender, the coxaj somewhat elongated; tibiae without terminal spurs. Wings rather large; auxiliary vein present, ending in costa before the middle of the wing; two complete basal cells.
This family may be readily recognized by the wing venation. The adults often dance in swarms at a height of a few inches to a few feet above the surface of small streams in swampy or wooded areas and occur also along the edges of ponds.
The larvge are aquatic and resemble those of mosquitoes but the thorax is not broadened. They are cylindrical, somewhat flattened be- neath, and n-shaped.
There are but two known genera, Ncodixa occurring only in New Zealand, and Dixa, which is cosmopolitan. I present a key, adapted from Edwards, to the genera and subgenera of the world.
FAMILY DIXID.T: 81
KEY TO GENERA
1. Second vein branched Dixa Meigen
Second vein simple (New Zealand) Neodixa Tonnoir
Subgenera of Dixa
1. Hind margin of the wing evenly rounded 2
Hind margin of wing produced at end of fifth vein; all veins in apical
part of wing parallel Dixapuella Dyar & Shannon
2. Crossvein connecting the fourth vein and anterior branch of the fifth
vein strong 3
Crossvein connecting anterior branch of the fifth vein and the fourth vein faint Dixella Dyar & Shannon
3. First flagellar segment fusiform or oval 4
First flagellar segment cylindrical, five times as long as wide.
Paradixa Tonnoir
4. First flagellar segment oval, about two and one-half times as long as
wide Nothodixa Edwards
First flagellar segment fusiform; at least three times as long as wide.
Dixa Meigen
82
NORTH AMERICAN DIPTERA
LIFE STAGES OF MOSQUITOES Culex Amopheles
Aedes Algypti
— tUESWSISSi'^i^
The life stages of three different genera of mosquitoes showing characteristic types of each and resting position of the adults (After Pieper and Beauchamp, from Metcalf and Sanderson).
83
Family Culicidae — The Mosquitoes
m^^xmnw^
I
I
/
^i
Aedes larv«. Note position at surface of water characteristic of the Culicini. (After Matheson, courtesy C. C. Thomas).
Slender, delicate flies, with slender legs and usualh^ with scales upon the body and appendages.
Head small, siibspherical; eyes reniform; ocelli absent. Antenna slender, elongate, composed of fourteen or fifteen segments, densely plumose in the males; first segment reduced to a narrow ring, second globose, the following elongated, nearly or quite cylindrical and with whorls of hairs, in the male the apical two segments elongated and nearly Ijare. Thorax ovate, arched but not projecting over the head, without transverse suture; scutellum short, evenly rounded or trilo- bate; metanotum ustially arched. Abdomen long and narrow, some- what arched, composed of nine or ten segments; male genitalia promi- nent but not large; ovipositor short. Legs long and slender, the coxas not elongate; tarsi long, the claws often denticulate. Wings long and narrow, at rest lying flat over the abdomen, with six fully developed longitudinal veins reaching the margin, the posterior margin fringed with hairs or scales, the costal vein extending around the wing; vena- tion as in figure; two basal cells, the veins usually clothed with scales.
84
NORTH AMERICAN DIPTERA
Anopheles larva. Compare position at surface of water with that of Aedes. (After Matheson, courtesy C. C. Thomas).
.-n '•)-■»?,
COMPOUND / EYE-
MAXILLARY PALP ^~
ANTENNA <
^LABRUM - " EPIPHARYNX — FOOD CHANNEL -HYPOPHARYNX -MANDIBLE l-'MAXILU
LABRUM- 7 EPIPHARYNX
^FOGO CHANNEL
-HYPOPHARYNX — SALIVARY DUCT ^MANDIBLE —MAXILLA
HYPOPHARYNX
MANDIBLE
LABELLA
MAXILLA
Head and mouth-parts of a mosquito. (After Metcalf and Sanderson).
FAMILY CULICID.T: THE MOSQUITOES 85
The mosquitoes are too well known to require hints as to where they may be found although it may be well to remark that a "swatted" mosquito does not make a suitable study specimen. Despite the fact that these flies are not altogether fi'agile it is nevertheless true thai most specimens in collections are in poor condition because the pre- servation of the insects in good state depends upon care in handling immediately after capture. Few specimens should be placed in a killing bottle and they should be mounted while fresh. All but the very small species should be pinned on fine steel pins and not mounted on points; the small ones should be fastened on the sides of pins, using a ring of white shellac. With careful collecting, care in pinning and proper preservation, a collection of these insects may be very attractive. Many of the adults are extremely beautiful although it must be admitted that most of those in the Nearetie region do not go in for fine colors : in the tropics many of the species are clothed in nature's most beautiful colors.
All mosquitoes are not injurious and many of them do not bite. Some are predaceous upon other mosquitoes in the larval stage and this is true of the Chaoboringe, which should, perhaps, be ranked as a dis- tinct family, since they almost entirely lack scales. Their larvJB are called ''Phantoms" because they are practically colorless.
So much has been written about mosquitoes during the present century that it would be impossible to review the entire literature in the space available but mention may be made of two books which will furnish a basis for intensive study for anyone interested. ]\Iatheson's "Handbook of the Mosquitoes of North America" deals with most of the species occurring in the ITnited States and Canada and gives a thorough resume of the medical and control aspects of the subject. Dyar's "Tlie Mosquitoes of the Americas" deals entirely Avith the tax- onomy of the group, but the descriptions are too brief and often omit important details: nevertheless it is an indispensable work nnd Avitli careful study and use of the figures will be found fairly- satisfactory.
I may say that the Culicida' are one of the most important fam- ilies of the Diptera insofar as human welfare is concerned. The diseases carried by them are not only lethal but cause extreme suffering and agony. Without doul:)t a much more extensive account of these insects might well be included in this work but space does not permit.
The diseases known to be transmitted by mosquitoes are Malaria. Blacl'wafer Fever, Yellow Fever, Dcngv.c, Filariasis, Bird Malaria and Fowl-pox. Of these ]\Ialaria and Yellow Fever are the most widely dis- tributed and much has been written about them. In at least the first five both the mosquito and man are essential in the life cycle of the
86
NORTH AMERICAN DIPTERA
Culicidaj I. — Lateral view of thorax of: 1, Uranotaenia loewii; 2, Theobaldia morsitans; 3, Anopheles punctipennis; 4, Psorophora ciliata ; o, Megarhinus septentrionalis. (After Matheson, courtesy C. C. Thomas).
l.m.e., lower mesepimeral bristles; pa., prealar bristles; pe., prothoracic bristles; pn., pronotal bristles; p.sp., postspiracular bristles; ps., prosternal or propleural bristles; sp., spiracular bristles; st.p., sternopleural bristles; u.me., upper mesepimeral bristles.
FAMILY CULICID.E — THE MOSQUITOES
87
Culicidae II. — Lateral view of thorax of: 6. Orthopodomyia signifer; 7, Deinocerites pseudes; 8, Wyeoinjia sinithii; 9, Culex pipiens ; Id, Mansonia perturbans; 11, Aedes vexans. (After Matheson, courtesy C. C. Thomas).
88 NORTH AMERICAN DIPTERA
causative organism, although other warm blooded animals may take the place of man. If the mosquitoes essential for the development of the organisms causing the disease were destroyed the disease would dis- appear entirely and it is because of this that such vigorous steps have been taken to stamp out mosquitoes in various parts of the world. The complete destruction of all disease carrying mosquitoes is scarcely pos- sible but it has been demonstrated in the Panama Canal Zone that they can be kept under control to such an extent that the diseases they carry are no longer a serious menace to residents of the region. It is now so well known that the construction of the Panama Canal was made possible only by the control of mosquitoes that no more than mention of the fact need be made here.
Malaria is still a common disease in many parts of the United States. ]\Iany of us think of it as a tropical or subtropical disease, but nothing could be further from the truth. Malaria has raged at one time or another over rather large areas of the northern states and may do so again if patients suffering from the disease in its active stage should be bitten by our native Anopheles mosquitoes and they have the opportunity of developing and injecting the ])rotozoan causing the fever into the blood stream of uninfected persons.
The North American Anopheles known to transmit the disease are quadrimaculatus, maculipennis, punctipennis, crucians, and atropus in the United States, alhimanus, pseudopunctipennis and quadrimaculatus in Mexico, and alhimanus and tarsimaculatus in Central America and the West Indies. The last three species named for the United States are not considered important vectors of the disease.
The causative organisms of Malaria are Plasmodium vivax for ter- tian, P. malarice for quartan, and P. falciparum for the pernicious type. Tertian is our commonest type, being approximately three times as prevalent as the other two combined, while the pernicious form is almost twice as prevalent as the quartan.
An idea of the essential part played by insects which act as inter- mediary hosts for parasites causing human diseases, may be obtained from a brief outline of the life cycle of Plasmodium vivax. The organ- ism passes an asexual stage in man, developing and multiplying in the red corpuscles, causing them to enlarge. In a little less than two days the trophozoites are mature, having absorbed the contents of the cell and the term schizont is now applied to them. These divide into from 15 to 24 merozoites and are discharged into the blood stream by ruptur- ing of the cell wall. The cycle now begins over again and the same process is repeated, but after a time certain of the merozoites develop into male (microgametocytes) and female (macrogametocytes) which
FxVMILY CULICID.E THE MOSQUITOES 89
remain in tlie red blood cells, no further development taking place. From this point on the mosquito becomes an essential factor since, unless they are ingested by a mosquito, the gamctocijtes are capable of no further development.
When the gametocytes are taken into the mosquito further develop- ment occurs, commencing in the stomach of the host. The female {macrogametocytes) mature into what is called a macrogamete, corre- sponding to a ripened but unfertilized ovule, while the microgameto- cytes give off a number of thin, elongate, worm-like bodies, the male elements or microgametes. These travel about by a lashing motion until they come in contact with a macrogamete, when they penetrate the cell wall and fertilization takes place, producing a zygote, a round body which soon elongates into an ookinete which becomes active, penetrates the wall of the stomach and establishes itself between the epithelial and muscular layers. In this position it absorbs food from the surrounding tissue, becomes spherical and very large, and in this stage is termed an oocyst. In this stage the spores (corresponding to eggs) are de- veloped, and arc called sporozoites. They escape by the breaking of the oocyst and enter the body cavity, where they are carried to all parts of the body by the free-flowing blood, many of them finding their way to the salivary glands and into the blood streams of human beings where they penetrate the red blood cells and develop into schizonts.
It will be seen from this that the sexual stage occurs in the mos- quito, occupying from eight to fourteen days, and probably results in no ill effects to its host, since it is a cold-blooded creature.
In tertian malaria a chill is produced about every three days, fol- lowed by fever, while in quartan malaria the chill occurs every four days, due to the longer incubation period of the merozoites, while in pernicious malaria the chills and fever are irregular.
Blackwater Fever is now believed to be the result of numerous attacks of malaria or a more or less continuous infection and derives its name from the fact that the patient's urine is of a dark mahogany color due to the presence of broken down red corpuscles.
Yellow Fever may be carried by at least three species of mos(iuitos in America Acdes (Stegomyia) aegypti, Avdes fluvialtilis and Aedes scapularis. Possibly other species might carry the disease as well but we fortunately do not have it in the United States, even though A. aegypti is common in the south. With present facilities for rapid transportation there is danger of travellers from yellow fever areas entering the country and developing the disease after arrival. If we were sure that the disease would be quickly diagnosed and the patient isolated in a mosquito-proof room we misfht feel much more certain
90
NORTH AMERICAN DIPTERA
Culicidse III. — 1, Megarhinus; 2, Megarhinus, d head; 3, Aedes, wing vena- tion; 4, Haemagogus; 5, Haemagogus, front claws of d ; 6, Wyeomyia, $; 7, Chaoborus, posterior tarsus.
3^.ua 2""-" ,^st,,,„
Venation of Aedes.
m-cu r-m
J
2da
cu.
Venation of Anopheles, giving Comstock-Needham terminology and that of Schiner, etc. (in brackets). Veins. — C, costal; Sc, subcostal (auxiliary); R, (first longitudinal); R2, R3, (second longitudinal); R4+0, (third longitudinal); M,+2, M3 (fourth longitudinal); Cu„ Cus (fifth longitudinal); 2 da., (sixth longi- tudinal); r-m, radio-medial crossvein (anterior crossvein); ni-cu, medio-cubital crossvein (posterior crossvein). Cells. — a, Sc, (subcostal); b, Ri, (first marg- inal); c, Ri (second marginal); d, R3 (submarginal) ; e, R., (first posterior); f, M2, (second posterior); g, Ms (third posterior); h. Cu, (fourth posterior); i, Cu; (anal); j, 2a, (axiliary). (After Matheson, courtesy C. C. Thom.as).
FAMILY CULICID/E THE MOSQUITOES 91
that the disease would not become established in this country, but, unfortunatel}', few doctors are familiar with the symptoms of yellow fever and there is grave danger of the disease remaining undiagnosed until it is too late to take precautionary measures. Even though steps have been taken to quarantine all persons coming from known yellow fever areas the danger of introduction of the disease is an ever present menace.
Dengue or Break-hone Fever is another disease carried by the Yellow Fever mosquito (Aedes aegypti). It is a common tropical and subtropical disease and there are occasional out])reaks in the Southern States, corresponding to the distribution of the mosquito. After biting a patient it requires from eight to eleven days before the mosquito is capable of transmitting the disease.
The microfilariae of Wuehereria hancrofti Cobbold are taken up (in America) by Culex fatigans Wiedemann and undergo development in the muscles of the mosquito, in much the same way as described for Malaria but there is no increase in numl^ers and they do not become sexually mature until they have been returned to the human body. The worms occur in the lymphatic system and may he responsil)le for a number of organic disturl)ances. The region about Charleston, South Carolina is the only area in the United Staates where Filariasis is preva- lent but it is common in the tropics of both liemispheres.
Since wi-iting the foregoing and preparing the following key, Edwards' fascicle in the "Genera Insectorum" (194), has appeared. In this work the Dixida? are included as a subfamily of the Culicidse, a course I do not follow. An examination of this important fasicle of "Genera Insectorum*' will disclose the fact that Edwards makes free use of su])genera. i\Iy views on this question are expressed else- where in this work. With the author's view tliat genera should be limited to grouj^s readily characterized in both sexes I most heartily agree. The quality of the scientific work of this author is of too high a standard to warrant criticism except of a most favorable nature and one can disagree with him only on questions of minor importance. The question of subgenera is really one of likes and dislikes, and I prefer to keep as close as possible to a binomial system of nomenclature.
Most of the cuts used to illustrate this family are from "A Hand- book of the Mosquitoes of North America" by Dr. Robert IMatheson and I wish to express my indebtedness to him and to Mr. C. C. Thomas, the publisher, for furnishing them, and also my appreciation of their wlioleliearted cooperation.
92
NORTH AMERICAN DIPTERA
/
^IK
-MxP f'
-E
•?^^i^
Aedes vexans. (After Matheson, courtesy C. C. Thomas).
FAMILY CULICID.E THE JIOSQUITOES 93
KEY TO GENERA*
1. Proboscis not elongate, extending but little beyond the clypeus; wings
with scales (when present) confined mostly to the fringe. (Chao-
borinas ) 2
Proboscis elongate, extending far beyond the clypeus; wings with the veins and margins with scales (Culicin^) 5
2. Anal vein ends beyond the fork of the fifth vein 3
Anal vein ends before the fork of fifth vein Eucorethra Underwood
3. First tarsal segment longer than the second 4
First tarsal segment shoi'ter than the second Mochlonyx Lcew
4. First vein ending much closer to the tip of the anterior branch of sec-
ond vein than to that of the auxiliary vein (III-7).
Chaoborus Lichtenstein First vein ending nearer to tip of auxiliary vein than to anterior branch of second vein Corethrella Coquillett
5. Abdomen without scales, or at least with the sternites largely bare;
scutellum with the margin convex, evenly setose; never a spurious vein behind fifth vein (1-3, and text figure of larva). .Anopheles Meigen Abdomen with both tergites and sternites completely clothed with scales; scutellum trilobed, the lobes alone setose; if scutellum evenly convex then a spurious vein behind fifth vein 6
6. Proboscis rigid, the outer half more slender and bent backwards; a
spurious vein behind the fiftli vein (1-5, III-l, III-2).
Megarhinus Desvoidy Proboscis more flexible, of uniform thickness (at times swollen at tip), outer half not bent back; never a spurious vein behind fifth vein. . . 7
7. Base of hind coxse in line with or above the upper margin of the meta-
steiTial sclerite S
Base of liind coxae below upper margin of metasternal sclerite 16
8. Pronotal setae absent; prothoracic lobes not widely separated 9
Pronotal setae present; prothoracic lobes widely separated 14
9. Prealar setae absent 10
Prealar setae present 1]
10. Propleural setae absent Sabethes Desvoidy
Propleural setae present Sabethoides Theobald
11. Spiracular setae present 12
Spiracular setae absent Limatus Theobald
12. Lower sternopleurals distinctly below the upper margin of metasternal
sclerite 13
Lower sternopleurals extending to or above the upper margin of the metasternal sclerite Dendromyia Theobald
13. Outstanding scales on at least the basal portion of the second and
third veins broad Miamyia Dyar
These scales usually narrow (II-8, III-6) Wyeomyia Theobald
* Checked by Dr. R. Matheson.
94
NORTH AMERICAN DIPTERA
Culex pipiens. (After Matheson, courtesy C. C. Thomas).
FAMILY CULICID.E THE MOSQUITOES 95
14. CI ypeus with setae Joblotia Blanchanl
Clypeus without setas 15
15. Lower steinopleuial sets extending: above the upper margin of the
metasternal sclerite Goeldia TheobaUl
Lower sternopleural setse not extending above the upper margin of the metasternal sclerite (I-l) Isostomyia Coquillett
16. Anal vein ending opposite or before the fork of the fifth vein.
Uranotaenia Arribalzaga Anal vein ending well beyond the fork of the fifth vein 17
17. Prescutellar sette and postspiracular setse absent (III-4, III-5).
Haemagogus Williston Px-escutellar setae present IS
IS. Postspiracular setaj present 19
Postspiracular sette absent 21
19. Spiracular setae absent 20
Spiracular setae present (1-4 and text figure) Psorophora Desvoidy
20. Wing scales narrow (rarely broad) or the base of first vein with setae
posteriorly on the upper side (II-ll, III-3, and text figs.).Aedes Meigen Wing scales broad; base of first vein bare (11-10) . . . . Mansonia Blanchard
21. Spiracular setae present (1-2) Theobaldia Neveu-Lemaire
Spiracular setae absent 22
22. First vein without sette basally on upper side; wing scales broad 23
First vein with setae basally on upper side; wide scales narrow 25
23. Fourth segment of front tarsi at least as broad as long (11-6).
Orthopodorayia Theobald Fourth segment of front tarsi longer than wide 24
24. Antennal segments little longer than wide Aedeomyia Theobald
Antennal segments much longer than wide (11-10).. . .Mansonia Blanchard
25. Antenna much longer than the length of the proboscis (II-7).
Deinocerites Theobald Antennae not longer than the length of the proboscis 26
26. Wings yellowish, spotted with black Lutzia Theobald
Wings never black-spotted (II-9 and text figure) Culex Linnaeus
KEY TO THE GENERA OF THE WORLD
1. Scales almost confined to the wing-fringe; mouth-parts short, the
palpi incurved (Chaoborinae) 2
Wing-veins and legs scaled; proboscis long; palpi not incurved (Culicinae) 7
2. Clypeus large and hairy; Ri ending close to tip of R- 3
Clypeus small and nearly bare; R, ending far from tip of R^.
Corethrella Coquillett
3. First tarsal segment much shorter than the second 4
First tarsal segment longer than the second 6
4. Tibiae spurred 5
Tibiae not spurred; metapieural hairs absent Mochlonyx Loew
96
NORTH AINIERICAN DIPTERA
Psorophora ciliata.
FAMILY CULICID.T: THE MOSQUITOES 97
5. Tibial spurs 1-2-2*; metapleural hairs present Cryophila Edwards
Tibial spurs 1-1-1; metapleura bare Promochlonyx Edwards
6. Clypeus as long as the head; claws larger and toothed.
Euforethra Underwood Clypeus shorter than the head; claws small and simple.
Chaoborus Lichtenstein
7. Abdomen without scales; or at least with the stemites largely bare
(Anophelini) 8
Abdomen with both tergites and sternites completely clothed with scales 10
8. Scutellum slightly trilobed Chagasia Cruz
Scutellum evenly rounded 9
9. Stem of median fork wavy Bironella Theobald
Stem of median fork straight Anopheles Meigen
10. Proboscis not rigid, of uniform thickness (unless swollen at tip), outer
half not bent backwards (Culiciiii) 11
Proboscis rigid, outer half slender and bent backwards (Megarhinini).
Megarhinus Desvoidy
11. Squama fringed (fringe usually complete, rarely interrupted); vein An
reaching well beyond base of cubital fork 12
Squama bare or rarely with 1-4 short hairs 30
12. Pulvilli present; pleural chaetotaxy well developed, but spiracular and
post-spiracular bristles absent 13
Pulvilli absent or rudimentary 14
13. Second antennal (first flagellar) segment short in both sexes; antennae
of c5" nearly always plumose Culex Linnaeus
Second antennal (first flagellar) segment elongate in both sexes; an- tennae of o' not plumose Deinocerites Theobald
14. Post-spiracular bristles absent; claws of ? simple (except in Leices-
teria, Haemagogus, and Heizmannia) 15
Post-spiracular bristles present, even if only one or two; claws of ? usually toothed; dorsocentral and upper sternopleural bristles nearly always well developed 25
15. Spiracular bristles present (sometimes only one or two) 16
Spiracular bristles absent 19
16. Several upper sternopleural bristles; stem-vein usually hairy beneath.
Theobaldia Neveu-Lemaire At most one or two upper sternopleural bristles; stem-vein bare be- neath 17
17. Postnotum nearly always bare (Oriental and Australasian).
Tripteroides Giles Postnotum with bristles (Neotropical) 18
18. Clypeus with setae Trichoprosopon Theobald
Clypeus bare Gceldia Theobald
* Posterior four tibia' each with two apical spurs.
98
NORTH AMERICAN DIPTERA
Corethra cinctipes.
FAMILY CULICID.T2 THE MOSQUITOES 99
19. Dorsocentral and pre-scutellar bristles absent; pronotal lobes approxi-
mated 20
Dorsocentral and pre-scutellar bristles well developed; pronotal lobes well separated 21
20. Postnotum usually bare (Neotropical) Ha^masogiis Williston
Postnotum usually with bristles (Oriental) Heizmannia Ludlow
21. Post-spiracular area scaly; ? claws usually toothed; 9 palpi more than
half as long as proboscis Armiseres Theobald
Subg-en. Leicesteria Theobald Post-spiracular area bare; ? claws simple 22
22. All segments of 9 antenna, and last two of o antenna short and thick;
middle femora with scale-tuft Aedeomyia Theobald
Antennae normal, slender; middle femora without scale-tuft 23
23. First segment of front tarsi longer than the last four together; fourth
very short in both sexes Orthopodomyia Theobald
First segment of front tarsi not longer than last four together; fourth not shortened in ? 24
24. Proboscis of o' much swollen apically, of ? slightly so, or else cell R2
shorter than its stem Ficalbia Theobald
Proboscis not swollen apically; cell R: at least as long as its stem.
Mansonia Blanchard
25. Head with numerous short hairs on vertex in addition to the orbital
row; antennae thick in both sexes, not plumose in o' Opifex Hutton
Head without hairs on vertex apart from the orbital row; antennae slender in ?, nearly always plumose in cT 26
26. Spiracular bristles present, even if few (American). .Psorophora Desvoidy Spiracular bristles absent 27
27. Eyes widely separated, space between them clothed with metallic
silvery scales (Ethiopian) Eretmopodites Theobald
Eyes less widely separated (sometimes touching), space between them not covered with metallic silvery scales 28
28. Wing-scales generally mostly narrow (when, rarely, all are broad, the
9 claws are toothed); usually a few hairs on upper surface of stem- vein 29
Wing scales all very broad; 9 claws simple; stem-vein bare.
Mansonia Blanchard
29. Proboscis more slender, not recurved at tip in repose; ornamentation
various Aedes Meigen
Proboscis rather stout, recurved at tip in repose; dark species with flat scales on vertex and scutellum Armigeres Theobald
30. Wing-membrane without microtrichia (or these only visible under a
high magnification); cell R2 shorter than its stem; An ends about
opposite base of cubital fork Uranotaenia Arribalzaga
Wing-membrane with distinct microtrichia (visible under a magnifica- tion of 50) 31
31. Postnotum bare; An (except in some species of Topomyia) ending little
if at all beyond base of cubital fork; two or more posterior pronotal bristles present (Palaeotropical) 32
100 NORTH AMERICAN DIPTERA
Postnotum with, bristles; An ending well beyond base of cubital fork; posterior pronotal bristles usually absent; spiracular bristles present (except in Limatus) (Neotropical) 35
32. Spiracular bristles absent; clypeus normal 33
Spiracular bristles present (one or more); clypeus rather small and
narrow; cell R- longer than its stem 34
33. Cell R2 shorter than its stem; several posterior pronotal bristles; wing
scales normal Zeugnomyia Leicester
Cell R2 longer than its stem; two posterior pronotal bristles; wing- scales emarginate at tips Hodgesia Theobald
34. Proboscis very hairy, much enlarged at tip Harpagomyia de Meijere
Proboscis not hairy, rarely enlarged at tip Topomyia Leicester
35. Middle legs with "paddles" formed of very long erect scales.
Sabethes Desvoidy Middle legs without "paddles" 36
36. Clypeus with hairs; large species with long 0 palpi.
Trichoprosopon Theobald Clypeus bare, or with scales only 37
37. Hind tarsi with long suberect scales; large species with long cT palpi.
Goeldia Theobald Hind tarsi with appressed scales only; smaller species with short o' palpi 38
38. No bristles on subalar knob; pronotal lobes large and almost in con-
tact; mesonotal scales all metallic Sabethoides Theobald
Bristles present on sub-alar knob; pronotal lobes more widely sepa- rated; mesonotal scales rarely metallic 39
39. Spiracular area with scales only; hind tarsus with one claw.
Limatus Theobald Spiracular area with 1-4 bristles, no scales; hind tarsus with two claws.
Wyeomyia Theobald
101
Family Cecidomyidae— The Gall Midges
Cecidomyida?— Thecodiplosis piniradiatae Snow and Mills. Eggs, pupa, laiA^a, "breast-bone" and imago. (Williston).
Small, delicate flies with broad wings and long antennae and legs.
Head small; eyes roinid or reniform, sometimes holoptic; ocelli usually absent; antennas long, cylindrical, the segments usually wath l)ead-like swellings, ten to thirty-six in number; proboscis short, rarely elongated; palpi with one to four segments. Thorax ovate, more or less convex, without transverse suture; abdomen composed of eight seg- ments; hypopygium small but projecting; ovipositor sometimes very long. Legs long and slender; coxiu rather short; tibia; without terminal spurs, Ijasal tarsal segment sometimes very short. Wings large, usually hairy, narrowed ])asally and without alula; three to five longitudinal veins, usually with only the first, third and fifth; humeral crossvein iudisfinct or absent; costal vein extending around the entire wing, the veins all weak, the fifth usually furcate; anterior crossvein situated v('r>- near the base of the wing, often appearing as the beginning of the third vein, the base of the third vein having the appearance of a cross- vein; only one liasal cell present.
These small flies may be found everywhere but the most satisfac- tory means of collecting them is to rear them. The larva of most of the species live in living plants where they form galls, or deformities of various kinds, in the axils of the leaves, etc. Others live under bark, in decaying vegetation and in fungi while a few live upon plant lice, being found for the most part under the colony of ai)hi(ls or in axils of the leaves during the day. ]Many of the species are iii(|uiliiu's in the galls formed ]\v other members of the family or even by other orders of insects. The galls occur on all parts of plants, on the flowers, leaves,
102
NORTH AMERICAN DIPTERA
'^"^
>-rjr-T)(irirT^
Cecidomyidas I. — 1, Lasioptera; 2, Porricondyla? ; 3, Cecidomyia; 4, Hor- momyia; 5, Trichopteromyia; 6, Lestremia; 7, Miastor; 8, Spaniocera?; 9, Catocha; 10, Colpodia; 11, Heteropeza; 12, Asynapta; 13, Winnertzia; 14, Lestodiplosis; 15, Winnertzia.
FAMILY CECIDOiAIYID.E THE GALL MIDGES 103
stems and roots and are usually characteristic for each species. The larvae may be recognized by the presence of a "breast bone" or chitin- ized process lying witliin the thorax and terminating behind the head. The phenomenon of pedogenesis occurs in some species belonging to the genus Miastor, that is the larva? produce eggs from ovary-like organs, the eggs hatch within the body and the young larvas devour the parent, later escaping and completing their development externally; several generations may be produced in this way, before the development of adult insects occurs.
The classification of the family is difficult and I have merely emended the key given by Dr. Felt.* For the most part little can be done without preparing slides of the adults, the whole insect being mounted. It is advisable to preserve dried specimens as well as the mounts, and the galls should always be kept along wuth the adults. Study of the group should not be attempted by anyone who is not pre- pared to spend years of painstaking work on his hobby. Such a study would prove of inestimable value and would fully repay the student for the time spent. Many of the species are serious pests, the chief among these being the Hessian fly.
I may add tliat the study of the galls themselves constitutes a fascinating past-time and Dr. Felt has given us an excellent treatise on this subject t and is, I believe, preparing a new and enlarged edition. The series of papers published by Dr. Felt is copiously illustrated and I have made free use of these illustrations. In connection with their use I cannot help but call attention to the splendid cooperation of Dr. C. C. Adams, of the New York State iMuseum, in furnishing the cuts used for this family and of Dr. Felt for assistance and suggestions. Most of the illustrations of Cccidomyida are from cuts furnished by the New York State Museum.
KEY TO GENERA
1. Circumfila present 23
Circumfila absent 2
2. Wings with four longitudinal veins 3
Wings with at most three longitudinal veins 17
3. Fourth vein forked 4
Fourth vein simple 10
4. Second antennal segment greatly enlarged 5
Second antennal segment normal 7
* 1925. Key to Gall Midges (A resume of Studies, i-vii. Itonidida?), N. Y. State Mus. Bull. No. 257. References to Parts i-vii will be found in this Bulletin.
t 1918. Key to American Gall Insects. N. Y. State Mus. Bull. No. 200.
104
NORTH AMERICAN DIPTERA
Cecidomvida? II. 16. Catocha Americana. (Courtesy New York State Museum, Albany. N. Y.)
FAMILY CECIDO-MYID.E — THE GALL MIDGES 105
5. Subcosta and third vein united as though by a very short crossvein.
Microcerata Felt Subcosta and third vein separate and with no trace of a crossvein ... (>
6. Branches of the fork of the fourth vein even Konisomyia Felt
Branches of the fork of the fourth vein irregular (22). . .Tritozyga Loew
7. Flagellate antennal segments sessile, with a length only a little
greater than their diameter Neocatocha Felt
Antennal segments not sessile, more elongate 8
8. Antennfe with not more than ten segments Neptunimyia Felt
Antenna with at least eleven segments 9
9. Costa ending at or a little beyond the tip of the third vein (6, 26).
Lestremia Meigen Costa extending beyond the apex of the wing (9, 16). . .Catocha Haliday
10. Third vein usually well separated from the costa and frequently
uniting with it at or beyond the apex 11
Third vein rarely extending to the apex of the wing; flagellate anten- nal segments subsessile in female, ornamented with crenul ate whorls or structures more complex than irregular whorls of simple hairs . . 14
11. Flagellate antennal segments globose, stemmed in both sexes, or the
second enlarged 12
Flagellate antennal segments cylindrical, sub-sessile, the second not enlarged (23) Mycophila Felt
12. Fourth vein absent 13
Fourth vein present (28) Joannisia Kieffer
13. Antennal segments stemmed (5) Trichopteromyia Williston
Antennal segments sessile, the second enlarged Ceratomyia Felt
14. Flagellate antennal seg-ments with a more or less distinct subapical
collar forming a more or less cup-shaped cavity; claws denticulate.
Prionellus Kieffer Flagellate segments with subapical whorl of stemmed disks or spines. 15
15. Flagellate segments with subapical whorl of stemmed disks; claws
with minute apical tooth Monardia Kieffer
Flagellate segments with spines 16
16. Flagellate segments with short, stout, usually recurved spines (24,
27 ) Cordylomyia Felt
Flagellate segments with short, stout, curved spines (32).
Corinthomyia Felt
17. First segment of the tarsi shorter than the second 19
First segment of the tarsi longer than the second 18
18. Tarsi with four segments; three longitudinal veins (7, 18).
Miastor Meinert Tarsi with three segments; two longitudinal veins (11).
Heteropeza Winnertz
19. Tarsi with five segments 20
Tarsi with two segments Oligarces Meinert
20. Wing membrane finely haired 21
Wing membrane scaled Kronoinyia Felt
106
NORTH AMERICAN DIPTERA
-^^
Cecidomyidse III. — 17, Asphondylia monacha ; 18, Miastor americana.
(Courtesy New Yoi-k State Museum, Albany, N. Y.)
FAMILY CECIDOMYID.E THE GALL MIDGES 107
21. Third vein extending to the apex of the wing 22
Third vein not extending to the apex of the wing Epimyia Felt
22. Palpi with four segments Johnsonomyia Felt
Palpi with only one segment (29) Leptosyna Kieffer
23. No crossvein uniting the third and first veins 29
A distinct crossvein uniting the third and first veins 24
24. Crossvein parallel or nearly so with the costa and apparently form-
ing a continuation of the third vein 27
Crossvein forming a well-marked angle with the costa 25
25. Four longitudinal veins 26
Three longitudinal veins (10) Colpodia Winnertz
26. Fifth vein absent Parawinnertzia Felt
Fifth vein well developed (13, 15, 25) Winnertzia Rondani
27. Three or five longitudinal veins 28
Four longitudinal veins (12) Asynapta Loew
28. Three longitudinal veins Dirhiza Loew
Five longitudinal veins Hormosomyia Felt
29. Costa thickly scaled; third vein usually very close to anterior margin
of wings; antennal segments cylindrical, sessile, short, never pro- duced 30
Costa rarely thickly clothed with scales, the third vein well separated from it; antennal segments usually longer than wide 36
30. Third vein, lying very close to the costa and uniting with it at or
before the middle of the wing, rarely at the distal third 32
Third vein well separated from the costa and uniting with it beyond the middle of the wing 31
31. Third vein and body thickly clothed with scales Trotteria Kieffer
Third vein and body not thickly clothed with scales.
Camptoneuromyia Felt
32. Mouth parts and thorax normal, not greatly prolonged 33
Mouth parts and thorax prolonged Clinorhyncha Loew
33. Palpi with one or two segments Asteromyia Felt
Palpi with three or four segments 34
34. Third and foiirth antennal segments coalescent or closely fused 35
Third and fourth antennal segments at least separated by a distinct
constriction Protaplonyx Felt
35. Three longitudinal veins, the fifth forked (1, 21) Lasioptera Meigen
Four simple longitudinal veins Neolasioptera Felt
36. Flagellate antennal segments cylindrical, never binodose in the male. . 37 Flagellate antennal segments in the male greatly produced, binodose;
circumfila usually forming long loops 60
37. Claws on at least one pair of legs toothed 38
Claws simple 50
38. Palpi with four segments 39
Palpi with not more than three segments 45
108
NORTH AMERICAN DIPTERA
CecidomyidBe IV. — 19, Rhabdophaga sp. ; 20, Dasyneura gibsoni. (Courtesy New York State Museum, Albany, N. Y.)
FAMILY CECIDOMYIIXE THE GALL MIDGES 109
39. Antennae with fourteen or more segments 40
Antennae with ten to thirteen, rarely with fourteen segments 43
40. Third vein uniting with the costa at or near the apex of the wing. ... 41 Third vein uniting with the co.sta well before the apex of the wing. . . 42
41. Ovipositor not chitinized apically; claws with one sti'ong tooth (19).
Rhabdophaga Westwood Ovipositor chitinized apically, blade-like, the claws weakly toothed.
Procystiphora Felt
42. Wing veins scaled, the membrane more or less brownish.
Lasiopteryx Stephens Veins not distinctly scaled, the membrane hyaline (20).
Dasyneura Rondani
43. Third vein uniting with the costa near the apex of the wing 44
Third vein uniting with the costa well before the apex of the wing.
Neuromyia Felt
44. Antennfe with thirteen or fourteen segments Cystiphora Kieffer
Antennae with twelve segments, genital harpes sickle-shaped, greatly
produced Harpomyia Felt
45. Palpi with two or three segments 4^!
Palpi with only one segment Ficiomyia Felt
46. Palpi with three segments 4S
Palpi with two segments 47
47. Antenna; with twelve segments Coccidomyia Felt
Antennae with fourteen to eighteen segments Diarthronomyia Felt
48. Claws with a single tooth 49
Claws pectinate Ctenodactylomyia Felt
49. Ovipositor with apica! spine; male clasper short, swollen.
Cystiphora Kieffer Ovipositor without apical spine; pulvilli nearly three times as long as the claws Allomyia Felt
50. Flagellate antennal segments cylindrical, not greatly elongated, usu-
ally stalked in the male; ovipositor not aciculate 51
Flagellate segments cylindrical, elongate, sessile; ovipositor usually aciculate 56
51. Palpi with one to three segments 53
Palpi with four segments 52
52. Third vein joining the costa at or near the apex of the wing (34).
Phytophaga Rondani Third vein joining the costa well before the apex of the wing.
Janetiella Kieffer
53. Ovipositor distinctly chitinized, aciculate or cultriform.
Sackenomyia Felt Ovipositor not chitinized 54
54. Palpi with only one or two segments 55
Palpi with three segments Oligotrophus Latreille
55. Pulvilli nearly twice as long as the empodium Walshomyia Felt
Pulvilli shorter than the empodium Rhopalomyia Riibsaamen
110
NORTH AMERICAN DIPTERA
Cecidomyida? V. — 21, Lasiopteia veroniae; 22. Tritozj ga sackeni ; 23. Mycophila fungi- cola; 24, Cordylomyia coloradensis.
(Courtesy New York State Museum. Albany. N. Y.)
FAINIILV CECIDOMVID.K THE GALL MIDGES 111
56. Ovipositor protractile, aciculate or nearly so; terminal clasper of male
usually unidentate or bidentate 57
Ovipositor exserted, with lobes or triangular plates apically; terminal clasper of male usually serrate apically 58
57. Palpi with four segments (33) Schizomyia Kieflfev
Palpi with two or three segments (17) Asphondylia Loew
58. Palpi with four segments 59
Palpi with three segments Feltomyia Kieffev
59. Flagellate antennal segments cylindrical, not strongly constricted;
circumfila usually with many fine reticulations in the male; pulvilli
usually shorter than the claws (31) Cincticornia Felt
Flagellate segments cylindrical, sometimes rather strongly con- stricted; circumfila forming transverse series of low lines or loops; lobes of ovipositor subtriangular Caryomyia Felt
60. Nodes of the male flagellate antennal segments equal, only two cir-
cumfila 61.
Nodes of male flagellate segments plainly unequal, three circumfila. . 71
61. Palpi with three or four segments 62
Palpi with one segment Kronodiplosis Felt
62. Palpi with four segments 64
Palpi with three segments 63
63. Terminal clasp segment irregular, pectinate apically.
Pectinodiplosis Felt Terminal clasp segment normal Dentifibula Felt
64. Claws on all the legs simple 67
Claws on at least the front legs toothed 65
65. Claws on all the legs toothed 66
Only the anterior claws toothed Toxomyia Felt
6G. Internal basal lobe of the basal clasp segment smooth, the dorsal and ventral plates broadly and slightly emarginate, the ovipositor with a length one-half that of the abdomen, protractile. . .Erosomyia Felt Internal basal lobe of the basal clasp segment rudimentary, smooth; dorsal plate truncate, ventral plate broadly and roundly emargi- nate; ovipositor moderately long Mangodiplosis Tavares
67. Wings of males with the posterior area greatly produced and broadly
rounded Lobopteromyia Felt
Wings normal, not unusually broad 68
68. Costa not clothed with .scales 69
Costa thickly clothed with scales Endaphis KiefFer
69. Third vein interrupting the costa at its union with the margin 70
Third vein not interrupting the costa at its union with the margin
(See text fig.) Thecodiplosis Kieffer
70. Wings hyaline Contarinia Rondani
Wings spotted Stictodiplosis Kieffer
71. Claws toothed on all the legs 72
Claws of at lea.st the posterior legs not toothed 84
112
NORTH AMERICAN DIPTERA
25
Cecidomyida? VI.— 25, Winnertzia pectinata; 26, Lestremia pini. fifth antennal segment of d ; 27, Cordylomyia brevicornis, fourth and fifth antennal segments ofn". (Courtesy New York State Museum. Albany, N. Y.)
FAMILY CECIDOMYID.E — THE GALL MIDGES 113
72. Palpi with four segments 75
Palpi with three segments 73
73. Basal clasp segment of male distinctly lobed Peridiplosis Feit
Basal clasp segment of male not lobed 74
74. Flagellate antennal segments of female subcylindrical.
Kalodiplosis Felt Flagellate antennal segments of female binodose (Brit. Guiana).
Epihormomyia Felt
75. Circumfila with one or more greatly produced bows or loops having a
length five to ten times that of the enlargement and extending at
approximately right angles to it. '. 76
Circumfila all about equal, nearly regular 80
76. Three well-developed circumfila on each flagellate antennal segment. . 77 Two well-developed, irregular circumfila; basal circumfila on the
distal enlargement forming a low band; pulvijli small .Bremia Rondani
77. All three circumfila irregular, the pulvilli i-udimentary.
Tribremia KiefFer At most two circumfila irregular 7S
78. Pulvilli shorter than the claws; two circumfila irregular 79
Pulvilli as long as or longer than the claws; one circumfila irregular.
Aphidolete.s Kieffer
79. Pulvilli slightly shorter than the claws, conspicuous. . .Isobremia Kieffer Pulvilli i-udimentary or wanting Cryptobremia Kieffer
80. Basal clasp segment of male genitalia with basal lobe; ovipositor
short and with large, orbicular lobes Youngomyia Felt
Basal clasp segment without basal lobe 81
81. Claws curved at neai'ly right angles 82
Claws curved but not at nearly right angles 83
82. Ventral plate moderately long, broadly emarginate; dorsal plate
moderately long, broad, deeply triangularly emarginate, the lobes
triangular; ovipositor short Cleodiplosis Felt
Dorsal and ventral plates short, broad, deeply emarginate.
Thomasia Eiibsaamen
83. Ovipositor slightly protractile, the lobes long, curved, and with two
or three subventral rows of obtuse spines Dicrodiplosis Kieffer
Ovipositor about half the length of the abdomen, the lobes with a length about six times the width; mouth parts prolonged (Brit. Guiana) Delphodiplosis Felt
84. Claws not toothed on any of the legs 92
Claws toothed on at least the front legs 85
85. Palpi with four segments 86
Palpi with three segments Diadiplosis Felt
86. Basal clasp segment lobed 87
Basal clasp segment not distinctly lobed 89
87. The lobe basal or sub-basal 88
The lobe apical, setose or spinose; terminal clasp segment subapical.
Lobodiplosis Felt
114
NORTH AMERICAN DIPTERA
Cecidomyidae VII.
FAMILY CECIDOMYID.E THE GALL MIDGES 315
88. Ventral plate or harpes strongly chitinized Coquillettomyia Felt
Ventral plate or harpes not chitinized Feltiella Riibsaamen
89. Terminal clasp seg-ment sub-fusiform, distinctly dilated; harpes
strongly chitinized and very complex (30) Karschomyia Felt
Not as above 90
90. Claws curved at nearly right angles Clinodiplosis Kieffer
Claws not curved at nearly right angles 91
91. Ventral plate almost linear, straight and much longer than the dorsal
plate Acaroletes Kieffer
Ventral plate not greatly produced Mycodiplosis Riibsaamen
92. Palpi with fewer than four segments 108
Palpi with four segments 93
93. Third vein uniting with the costa behind the apex of the wing 9i
Third vein uniting with the costa before the apex of the wing.
Arthrocnodax Riibsaamen
94. Circumfila with short bows or wanting 95
Circumfila well developed and not conspicuously irregular, the loops
mostly as long as or longer than the diameter of the enlargement.. 97
95. Some of the flagellate antennal segments cylindrical 96
Flagellate antennal segments binodose in the male or presumably so.
Caryomyia Felt
9G. Circumfila rudimentary or wanting; tenth to fourteenth segments
cylindrical; harpes somewhat inflated Prodiplosis Felt
Circumfila distinct though low, all the flagellate or only the distal segments cylindrical; ovipositor short Caryomyia Felt
97. Claws bent at nearly right angles 98
Claws not bent at right angles 99
98. Ventral plate long, slender, slightly expanded and roundly emarginate
apically; dorsal plate short, triangularly emarginate. .Giardomyia Felt Ventral plate long, broad, very deeply and broadly emarginate; dor- sal plate deeply and roundly emarginate Hyperdiplosis Felt
99. Basal clasp segment lobed 100
Basal clasp segment not lobed 103
100. The lobe apical 101
The lobe basal 102
101. The lobe very long, cui'\'ed, setose; terminal clasp segment swollen
basally Epidiplosis Felt
The lobe triang-ular; terminal clasp segment short, greatly con- stricted near the middle and enormously swollen and recurved apically Metadiplosis Felt
102. Wings spotted Lestodiplosis Kieffer
Wings not spotted Coprodiplosis Kieffer
103. Antennal segments plainly trinodose Obolodiplosis Felt
Antennal segments not plainly trinodose 104
Ceeidomyidae VII. — 28, Joannisia phofophila, fifth and teith antennal segments of male • 29. Lcptosyna quercivora; ;{0. Karschoinjia viburni, fifth antennal sesment of d: 31. Cincti- cornia transversa, sixth antennal setrment of c ; 32, Corinthomyia cincinna, fourth antennal segment of d ; 33, Schizomyia macrolila, sixth antennal segment of d-
(Courtesy New York State Museum, Albany, N. Y.)
116
NORTH AMERICAN DIPTERA
34
Cecidomyidae VIII.— 34. Phytophaga destructor. (Courtesy New York State Museum, Albany, N. Y.)
FAMILY CECIDOMYID.E THE GALL MIDGES 117
104, Antennal segments short, thick, the stems transverse, the enlarge-
ments short and broad; circumfila fine, rather short, each with
about twenty loops Retinodiplosis Kieffer
Antennae of normal form 105
105. Ventral plate linear or long and spatulate 10^
Ventral plate broad and broadly or triangularly emarginate 107
lOG. Ventral plate linear, rounded apically; dorsal plate shorter than the
ventral, the lobes truncate Parallelodiplosis Riibsaamen
Ventral plate spatulate, the dorsal plate moderately long, deeply and triangularly emarginate, the lobes broad, obliquely and roundly emarginate Hypodiplosis Kieffer
107. Dorsal plate deeply incised, the lobes narrowly rounded; terminal
clasp segment with serrate margin Paradiplosis Felt,
Dorsal plate not incised or very narrowly emarginate; terminal clasp segment smooth (3) Cecidomyia Meigen
108. Palpi with three segments 100
Palpi with only one or two segments ll-»
109. Circumfila with short bows or loops, their length being one-half the
diameter of the enlargement or less 110
Circumfila loops with a length equal to the diameter of the enlarge- ment or longer s H-
110. Thorax plainly extending over and concealing the head to a certain
extent ....". Hi
Thorax not produced over the head to a marked degree. .Caryomyia Felt
111. Males with fifteen to at least twenty-seven antennal segments; female
with fourteen or more antennal segments; ovipositor short (4).
Hormomyia Loew Male and female with fourteen or fifteen antennal segments, the fifteenth rudimentary; ovipositor moderately long.
Trishormomyia Kieffer
112. Basal clasp segment lobed Odontodiplosis Felt
Basal clasp segment simple Adiplosis Felt
113. Palpi with two segments Dishormomyia Kieffer
Palpi with one segment 114
114. Wings hyaline 115
Wings marked with black and yellow Astrodiplosis Felt
115. Fourteen antennal segments in both sexes 11*3
Thirteen segments in female, the third and fourth fused, the basal
and distal nodes in the male flagellate antennal segments globose and ovoid respectively; dorsal and ventral plates bilobed; ovipositor short, chitinous, aciculate Cystodiplosis Kieffer & Jorg
116. Both dorsal and ventral plates deeply emarginate; ovipositor short,
chitinous, falcate Monarthropalpus Riibsaamen
Ventral plate not deeply emarginate 117
117. Dorsal plate deeply and ventral plate broadly emarginate; ovipositor
stout, half as long as the abdomen, the distal part thickly clothed
with long, silky hairs Onodiplosis Felt
Dorsal plate deeply, broadly and roundly emarginate, the lateral margin extended ventrally; ventral plate broadly emarginate; ovi- positor stout, about two-thirds as long as the abdomen.
Horidiplosis Felt
118
NORTH AMERICAN DIPTERA
Family Sciaridae — The Dark Winged Fungus Gnats
Sciara ci",
Usually small, blackish, brownish or testaceous species, the abdomen cylindrical and tapering, especially in the females.
The insects belonging to this family are related to the Myceto- philidffi, with which they have, until recently, been united. They differ in having the eyes produced toward each other above the antennae, instead of being regularly convex in outline, and in having shorter coxge. As a general rule the wing venation is typical although a very few genera of the Mycetophilidge have similar venation.
The adults inhabit moist places or any place where fungus growth occurs, particularly manure. The larva frequently become pests in mushroom cellars, feeding upon the mycelium of the fungi. The females are difficult to determine, the classification being based mainly on the male genitalia although the ovipositors of the females also offer good characters. The larvae, like those of the Mycetophilidse, have some very interesting habits, some of them sometimes travelling over the ground in snake-like masses. The family is treated by Johannsen in the refer- ence given under the Mycetophilidae.
FAMILY SCIARID.E — THE DARK WIXGED FUNGUS GNATS
119
KEY TO GENERA
1. Proboscis longer than the thorax (2) Eugnoriste Coquillett
Pi'oboscis not greatly elongate 2
2. Wings conspicuously hairy; claws never denticulate. . .Trichosia Winiiertz Wings with microscopic setulse but not hairy 3
3. Claws toothed 4
Claws not toothed 5
4. Forks of the fourth vein arcuate Metangela RUbsaamen
Forks of the fourth vein not arcuate Phorodonta Coquillett
5. Face strongly produced Rhynchosciara Riibsaamen
Face not produced 6
6. Forks of the fourth vein arcuate; antennae of the male pedicellate and
with whorls of hair (1) Zygoneura Meigen
Forks of the fourth vein not arcuate; antennae never pedicellate (Neosciara) (6, 7, Mycetophilidae) Sciara Meigen
Sciaridaj. — 1, Zygoneura; 2, Eugnoriste.
120 NORTH AMERICAN DIPTERA
Family Mycetophilidae — The Fungus Gnats
I\Ioderately small, rather delicate, slender flies with elongated
COXffi.
Head small, rounded or somewhat elongate, usually closely applied to the thorax. Eyes round, rather prominent; ocelli three, two or none, the median one often small, the lateral ones frequently close to the orbits; front broad in both sexes. Antennae elongated, composed of twelve to seventeen segments, the two basal segments large or dif- ferentiated, the others cylindrical, flattened or petiolated. Proboscis usually short, rarely greatly lengthened; palpi rarely absent, composed of three or four segments, usually inflexed. Thorax distinctly to strongly arched, without transverse suture; scutellum small; metanotum large. Abdomen composed of six or seven segments, cylindrical or com- pressed either laterally or dorsoventrally, sometimes narrowed basally; male genitalia projecting; ovipositor pointed, usually with two terminal lamella?. Legs more or less elongated, the femora usually thickened; coxge elongated; tibia with spurs and usually with series of short or conspicuous bristles. Wings large; auxiliary vein present though some- times very short; second longitudinal vein absent, or simulating a crossvein; third vein arising from the first vein, usually at such an angle as to simulate a crossvein, the crossvein sometimes appearing to form the base of the third vein; fourth and fifth veins usually furcate, sometimes simple; sixth vein sometimes rudimentary, never furcate; the seventh usually short, often rudimentary or entirely absent; discal cell absent, the second basal cell often open apically.
The adults are found in moist places, especially about decaying wood, on mossy rocks or moist humus, and prefer dark places. Many of the species are quite small only a few being large and conspicuous. They occur in a variety of habitats and some species are very restricted in habitat although occurring over a very wide geographical range. They may be collected throughout most of the year and when encoun- tered often occur in large numbers. The larva live in moist soil, wood, fungi, etc., and probably feed upon fungus growth. Pupation takes place outside the larval skin, some species spinning cocoons. The habits of the larva are particularly interesting and their investigation should provide an entertaining and profitable field of study to some one inter- ested in pure science for the fun of the thing. Johannsen* has mono- graphed the family and only a small number of North American species have been described since.
Maine Agric. Exp. Sta. Bulls. 172, 180, 196. 200, 1909-12.
FAMILY MYCETOPHILID.E — THE FUNGUS GNATS 121
KEY TO GENERA*
1. Second basal cell closed apically 2
Second basal cell open apically 12
2. Anterior branch of third vein at least half as long as posterior branch;
auxiliary vein short, ending free; posterior divisions of pronotum with
one or more long bristles (Ditomyiinge) 11
Anterior branch of third vein less than half as long as posterior branch, in some cases vestigial or absent; auxiliary vein in most cases long and ending in the costa; posterior divisions of pronotum without long bristles 3
3. The second basal cell much shorter than the first; first and second basal
cells separated (Bolitophilinse) (18) Bolitophila Meigen
The second basal cell almost as long as the first or the basal sections of the third and fourth veins fused for a short distance 4
4. Both crossveins closing the basal cells present, nearly in a straight
line; basal section of fourth vein lacking (Diadocidinte) (19).
Diadocidia Rutlie Basal sections of third and fourth veins fused for a short distance ex- cept in Palteoplatyura in which basal section of fourth vein is present o
5. Antennae long and slender, in most cases longer than the body (Macro-
cerinjB) (4) Macrocera Meigen
Antennce more robust, in some cases distinctly thickened and flatteried (Ceroplatinffi) G
6. Proboscis prolonged into a snout Asindulum Latreille
Proboscis not prolonged into a snout 7
7. Antennae conspicuously flattened; palpi porrect (Heteropterna, Cerote-
lion, Euceroplatus) (5) Ceroplatus Bosc
Antennae not conspicuously flattened, palpi curved 8
8. The anterior crossvein not obliterated by the fusion of the bases of the
third and fourth veins (20) Paheoplatyura Meunier
The anterior crossvein not obliterated by the fusion of the base of the third and fourth veins 9
9. Basal section of fourth vein absent (Isoneuromyia, Neoplatyura, Proeero-
platus, Lapyruta, Micrapemon) (9) Platyura Meigen
Basal section of fourth vein present 10
10. Ocelli wanting; anterior branch of third vein ending in the costa.
Hesperodes Coquillett Ocelli present, anterior branch of third vein ending in the first vein (21) Apemon Johannsen
11. Fork of fourth vein distal of fork of third vein (22) . . .Ditomyia Winnertz Fork of fourth vein basal of fork of third vein (14) . . .Symmerus Walker
12. First and third veins arising separately at base of wing; venation de-
fective; proboscis elongate (Lygistorrhinae) (Probolaeus) (2, ,3).
Lygistorrhina Skuse First and third veins arising from a common stem well beyond base of wing • 13