TYPICAL FLIES A PHOTOGRAPHIC ATLAS BY E. K. PEARCE SECOND SERIES CAMBRIDGE AT THE UNIVERSITY PRESS 1921 THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES TYPICAL FLIES CAMBRIDGE UNIVERSITY PRESS C. F. CLAY, MANAGER LONDON : FETTER LANE, E.G. 4 LONDON : H. K. LEWIS AND CO., LTD., 136, Gower Street, W.C. i LONDON : WHELDON & WESLEY, LTD., 28, Essex Street, Strand NEW YORK : THE MACMILLAN CO. BOMBAY ) CALCUTTA L MACMILLAN AND CO., LTD. MADRAS J TORONTO : THE MACMILLAN CO. OF CANADA, LTD. TOKYO : MARUZEN-KABUSHIKI-KAISHA ALL RIGHTS RESERVED TYPICAL FLIES A PHOTOGRAPHIC ATLAS BY E. K. PEARCE SECOND SERIES CAMBRIDGE AT THE UNIVERSITY PRESS 1921 32. PREFACE TO THE SECOND SERIES THIS supplementary volume of 'Typical 'Flies endeavours to complete the series of British Types, which, before the Great War, Professor Theobald was good enough to select and suggest as a sort of itinerary. And his notes in both volumes, especially those on larvae in the present volume, have greatly added to their value. Thanks are due in addition to the British Museum; to the Museum of Mr Rothschild at Tring, for the loan of micro-slides of the Nycteribiidae ; and to Mr H. Wad- dington, of Bournemouth, for micro-slides of the Culicidae. To the late Mr F. C. Adams, of the New Forest, and to Mr N. D. F. Pearce, of Grantchester, for various notes and specimens captured by them 1 . The only specimens which were included in the original list, and have not been obtained sufficiently well set for photography, are those of Medeterus micaceus, Agromyza lutea, Diplosis pyrivora, and of Oscinis frit, to be added later. To Mr Harwood, of Sudbury (Suffolk), I am again greatly indebted for many specimens, especially those of Trypetidae 2 , and seq. There appeared to be no recent illustrations of these beautiful flies and similar species, or even of some rare and common flies, of which identification is difficult. So these, too, have been included in this little volume. It is not claimed that the venation is always clear ; that would be difficult to secure in many cases : but every effort has been made to give a clue to the collector. Whenever possible a comparison with actual named specimens in collections and museums, or with lens, is desirable. The requirements of the Dipterist have been dealt with in the previous volume. They include a good net, bottles, pins, fine brushes, and forceps, for setting. Setting boards, killing bottles, cork- lined boxes for keeping specimens (in these expensive days of cabinets), a low-power microscope, and a good hand lens are desiderata. The hours for collecting are those of calm, March to October; a warm sun is essential. For unknown reasons specimens not only inhabit 1 I greatly regret to hear of the death of Mr Adams since this series of Typical Flies went to press. 1 In the Entomologists Record and Journal of Variation Mr T. C. Collins deals with the variation in wing markings of Trypetidae, stating that the banded mottled wings constitute specified and even generic characters. vi PREFACE TO THE SECOND SERIES certain districts, but as often desert them for even a term of years. Nevertheless, it is in well-known resorts that the capture of certain species is alone possible. A classification of Brauer will be found in this volume, as in its predecessor; a cross marks the specimens contained in this volume, and a star intimates they will be found in the preceding volume. It is hoped that this little book may not be in vain in inducing students to commence a study of wide possibilities. The following books may be of use to the student : Theobald's Monographs of the Culicidae. (British Museum : some of which are out of print.) Verrall's List of British Diptera. British Flies (two volumes). Austen's Bloodsucking Flies. (British Museum of Natural History.) Parasitology, Vol. IX, No. 4. July 27, 1917. C.U.P. Notes on Nycteribiidae. Staveley's British Insects. Instructions for Collectors. (British Museum.) Insects at Home. (Wood.) A map showing known distribution of Anopheles mosquitos. (British Museum.) In the Exhibited Series of Insects in the Department of Zoology, British Museum. (Natural History), Cromwell Road, S.W., will be found a short series of British Diptera : those in table cases having fine enlarged coloured illustrations on the lids of the cases, of great use to students the main collections of the Museum being reserved elsewhere. E. K. PEARCE. KEMPSTON, BOURNEMOUTH, Aug. \6th t 1921. PREFACE TO THE FIRST SERIES THE study of Diptera (two-winged flies) is rendered peculiarly difficult by the lack of elementary treatises on the subject. Certain groups are fully treated in the two large (and costly) volumes published by the late Mr Verrall, there are a few scattered papers in various magazines, and one or two monographs (such as Lowne's on the Blowfly) ; but there is nothing to compare with the numerous manuals dealing with Lepidoptera and Coleoptera, to name two orders only. This little book does not claim to fill the gap, but it is hoped that it may be of some use to the beginner, and attract attention to an order which possesses great interest, and is moreover of much economic importance. It is chiefly a picture book, as pictures appeal more to the eye than many pages of letterpress; and an important dipterous character the venation of the wings can be rendered with fidelity in a photograph. I have found it difficult to obtain specimens set sufficiently flat for photographic reproduction ; since, in photographing on the enlarged scale required, no amount of " stopping down " will produce an image sharp all over, unless the subject be fairly in one plane: in addition to this, some species when set and dried shrivel up, and give but a poor idea of their appearance when fresh. This of course chiefly applies to the bodies of flies, the wings and legs are not so affected. Flies may be taken with the usual entomological net, preferably a green one, as less likely to cause alarm than a white one. Mosquito netting, which may be dyed the required colour, is much better than green leno. The net should be fairly large, but light and easily managed, as many flies are very swift and strong on the wing. When caught, the fly may be transferred to a glass bottomed entomological box : a good supply should be carried, and it is better that only one specimen be placed in a box. On returning home the flies may be killed in a laurel bottle, care being taken that the leaves do not become mildewed, which would probably ruin the specimens ; a circular piece of white blotting paper should be placed over the leaves, and frequently renewed. Flies should remain in the bottle till they are thoroughly relaxed, which will require a day or two; if left too long they become rotten viii PREFACE TO THE FIRST SERIES and easily break whilst setting. Narrow boards, such as are used for the smallest lepidoptera, will be suitable for large and medium sized flies ; small ones may be set on strips of flat cork, covered with thin white paper. Entomological forceps will be needed to insert the pin in the thorax of the fly ; I prefer these curved, as they are also useful for moving pinned specimens. If the flies are to be photographed the pin must be cut off as short as possible above the thorax, and the cut end blackened with a touch of " matt black." No. 20 pins will be use- ful for most flies, though the large species require something stronger, whilst the very small ones, if pinned at all, require the finest silver pins obtainable. Taylor, New Hall Works, Birmingham, will supply a sample card of pins. For setting, strips and triangles of stiff writing paper, to hold legs and wings in place, and a stiff sable paint-brush, a few handled bristles and a fine needle or two, also handled, will do all that is required : a lens is indispensable in setting small flies, and may with advantage be mounted on a simple stand to leave both hands free. Some flies, especially the Tachinidae, are very brittle: care must be taken in manipulating them. Culicidae should be set and photo- graphed as quickly as possible, they very soon shrivel. Other flies may remain about ten days on the setting boards. As to numbers, half a dozen specimens should be ample, both sexes being represented, where possible. Fewer will often have to suffice with rare species, and for purposes of photography one well set specimen would be sufficient, were it not for the ever present risk of damage in moving from the store box: the slightest touch or jar will often cause the loss of a leg or antenna, and the attempt to replace these is seldom successful. Store boxes may be had in many sizes (10x8 inches is as good as any) ; whatever size is used should be adhered to, as far as possible, for the sake of uniformity. They should be carefully examined for mites, a great enemy to the collector; even new boxes are sometimes contaminated. In sending flies by post it is well to use two boxes, pinning them well into the inner, and supporting them by extra pins if possible; then packing the box with shavings inside a larger one. The label will of course be tied on. When finally pinning flies into the store box it is essential to use a small label giving date and locality, which can be pinned, written side down, by the same pin as the specimen. The name, etc. of the fly is written on a second label and pinned behind it in the box: the sex should be marked, where known, and a number added to correspond with that in a notebook, where fuller details may be recorded. Flies should be stored in a cool PREFACE TO THE FIRST SERIES ix dry place, free from accidental jars and careless handling. Naphthalin wrapped in a piece of net should be pinned in a corner of the box as a guard against mites, the great enemy of the dipterist as of the entomologist in general. The chief season for collecting in this country is from March till October, the sunny forenoon being the best time. Windy days are very unproductive. Even well-known and good localities are sometimes a blank, from causes we do not know, for flies seem very capricious in their habits. But, like other creatures, they have special haunts where they may usually be found at the proper season, and where they may be expected to occur if carefully searched for. Considerable experience in their habits and localities is needed by the collector. Generally speaking, umbelliferous plants, also bramble, hawthorn and ivy bloom seem to be most attractive. Flies often settle upon gate-posts, railings, and tree-trunks, especially if wounded or decayed. Others frequent salt-marshes and swamps, ponds and river-sides ; whilst heath-lands, sheepruns, bare hot sandy areas and commons attract others. Horse and cattle droppings and decomposing animal and vegetable matter are well-known baits for many species. Others attack living animals, not excepting man ; and certain flies prey on insects and spiders. Should horses or cattle be approached for the purpose of taking flies, much care must be exercised, as a net will generally stampede them ; it is difficult to employ it to advantage under such conditions. This little book has received the kind encouragement of many entomologists, among whom I may mention Professor Nuttall and Mr Warburton, both of Cambridge. Much practical help in the selection of species, and information as to types selected and their larvae, has been afforded by the kindness of Professor Theobald, whose assistance, it is hoped, has added greatly to the utility of this book. Thanks are also due to Mr Harwood, of Colchester, for the fine speci- mens of diptera which he has furnished for the photographs herewith presented. It has not always been possible to do them justice, owing to the difficulties previously noted as besetting the photographer. Mr H. Waddington kindly supplied some fine microscopic slides. The author's brother, Mr N. D. F. Pearce, has also helped with the illustrations, as to the success of which the reader must be left to judge. Acknowledgement has been made in every case, it is thought, where help has been received : and if this effort is successful it is hoped that it may be some day supplemented by a further series of pictures, to fill a few gaps that were unavoidable in the present volume. x PREFACE TO THE FIRST SERIES The life history (ovum, larva, pupa) of many of the species shown is yet to be traced by entomologists. Measurements are given in every case in millimetres (25 mm. = I inch), the first dimension being the length of the fly, and the second the expanse of wings. For various reasons it has not been found possible to reproduce the specimens on one uniform scale : the same difficulty was met with by Dr Michael in illustrating the Oribatidae. E. K. PEARCE. BOURNEMOUTH. June 1915. Scale of 3 centimetres of which one is divided into 10 millimetres. BRAUER'S CLASSIFICATION OF DIPTERA (t A cross denotes that the family is illustrated in this book. * An asterisk intimates they will be found in the preceding volume.) Sub-order i. ORTHORRHAPHA Larva with a distinct head. Pupa obtected. The adult escapes from the pupal skin by a straight dorsal slit which may be transverse but is more usually longitudinal. Imago lacks the frontal lunule and ptilinum. Sub-order 2. CYCLORRHAPHA Larva without any distinct head. The Pupa coarctate. The adult escapes from the puparium through a more or less round opening at the anterior end. Frontal lunule present ; ptilinum usually present. Sub-order I. ORTHORRHAPHA Section I. NEMATOCERA Typical Flies. Second Series. ERRATA Figs. 46, 47. For Anthrax circumdatus read Villa circumdata Mg. Fig. 48. For Habitat of Anthrax circumdatus read Habitat of Villa circumdata. Fig. 72. For Spilogaster Zoe $ read Spilographa Zoe Mg. $ Fig. 91. For Spilographa Zoe Mg. ct read Spilographa ZoeMg. $ x PREFACE TO THE FIRST SERIES The life history (ovum, larva, pupa) of many of the species shown is yet to be traced by entomologists. Measurements are given in every case in millimetres (25 mm. = I inch), the first dimension being the length of the fly, and the second the expanse of wings. For various reasons it has not been found possible to reproduce the specimens on one uniform scale : the same difficulty was met with by Dr Michael in illustrating the Oribatidae. E. K. PEARCE. BOURNEMOUTH. June 1915. Scale of 3 centimetres of which one is divided into 10 millimetres. BRAUER'S CLASSIFICATION OF DIPTERA (t A cross denotes that the family is illustrated in this book. * An asterisk intimates they will be found in the preceding volume.) Sub-order i. ORTHORRHAPHA Larva with a distinct head. Pupa obtected. The adult escapes from the pupal skin by a straight dorsal slit which may be transverse but is more usually longitudinal. Imago lacks the frontal lunule and ptilinum. Sub-order 2. CYCLORRHAPHA Larva without any distinct head. The Pupa coarctate. The adult escapes from the puparium through a more or less round opening at the anterior end. Frontal lunule present ; ptilinum usually present. Sub-order i. ORTHORRHAPHA Section I. NEMATOCERA Antennae long and thread-like, composed of many similar or very similar segments. The maxillary palpi usually elongate and flexible of from 2 to 5 segments. Second long vein often forked. Section II. BRACK YCERA Antennae usually of three segments, the third usually elongated and sometimes composed of a number of indistinct sub-segments and often bearing a style or arista. Maxillary palpi of i to 2 segments, not flexible. Second long vein not forked. Squamae completely con- cealing the halteres. xii CLASSIFICATION OF DIPTERA i. THE ORTHORRHAPHA. Section I. NEMATOCERA contain the following families : *i. J Pulicidae (Fleas). *2. Cecidomyidae (Gall Midges). f*3. Mycetophilidae (Fungus Gnats). f*4. Bibionidae (Fever Flies, St Mark's Flies). t*5- Simuliidae (Sand Flies). *6. Chironomidae (Midges). 7. Orphnephilidae. f8. Psychodidae (Owl Midges). f*9. Culicidae (Mosquitoes), fio. Dixidae. *n. Ptychopteridae (False Daddy Long Legs). *I2. Limnobiidae (False Daddy Long Legs). t*i3. Tipulidae (True Daddy Long Legs). *I4. Rhyphidae (Window Flies). Section II. BRACHYCERA t*i5' Stratiomyidae (Chameleon Flies). f*i6. Tabanidae (Gad Flies). *!?. Leptidae (Leptis Flies). f*i8. Asilidae (Robber Flies). 1*19. Bombylidae. *2O. Therevidae. y2i. Scenopinidae. +22. Cyrtidae. |*23. Empidae (Empis Flies). f*24. Dolichopodidae. [25. Lonchopteridae. 2. THE CYCLORRHAPHA. Section I. ASCHIZA Frontal lunule more or less indefinite ; no frontal suture. *26. Platypezidae. f2/. Pipunculidae. t*28. Syrphidae (Hover Flies). 1 These are by some raised to the rank of an order called Aphaniptera or Siphonaptera.) but there is no reason whatever for separating the Fleas or Pulicidae from the Diptera. CLASSIFICATION OF DIPTERA xiii Section II. SCHIZOPHORA Frontal lunule and frontal suture marked. Sub-section A. MUSCOIDEA Produce ova as a rule. Sub-section B. PUPIPARA Produce fully matured larvae. Sub-section A. MUSCOIDEA Series a. Acalyptrata Squamae small, not concealing the halteres. Series b. Calyptrata Squamae concealing the halteres. Section II. SCHIZOPHORA Sub-section A. MUSCOIDEA. Series a. Acalyptrata *29. Conopidae. t*30. Cordyluridae. 3 1 . Phycodromidae. 32. Helomyzidae. 33. Heteroneuridae. f*34. Sciomyzidae. f3S. Psilidae. 36. Micropezidae. t37. Ortalidae. f*38. Trypetidae. f39. Lonchaeidae. 40. Sapromyzidae. j*4i. Opomyzidae. 42. Sepsidae. f43. Piophilidae (Cheese Flies, etc.). 44. Geomyzidae. 45. Ephydridae. ^46. Drosophilidae. *47. Chloropidae (Gout Flies). 48. Milichidae. 49. Agromyzidae. fSO. Phytomyzidae. xiv CLASSIFICATION OF DIPTERA 51. Astiadae. f52. Borboridae. f53. Phoridae. Sub-section A. MUSCOIDEA. Series b. Calyptrata. t*54- Oestridae (Warble Flies). f*55. ^achinidae (Tachina Flies). f*56. Muscidae (House Flies, etc.). f*57. Anthomyidae (Root-feeding Maggots, etc.). Sub-section B. PUPIPARA t*58. Hippoboscidae (Forest Flies). |59. Braulidae (Bee Flies). f6o. Nycteribiidae (Bat Flies). 1 The Sarcophaginae and Dexinae are sometimes separated from the Tachinidae as two separate families. ORTHORRHAPHA NEMATOCERA Mycetophilidae Bibionidae Fig. 2. Scatopse notata L. 4x7-5 mm. Plentiful on windows end of May. The larvae live on vege- Fig. i. Platyura niarginata Mg. 8x12 mm. table and decaying matter. They are long and Found by sweeping. Most species inhabit woods fusiform and show two points at the sides of the and thickets. The larvae of Platyura feed on fungi. prothorax, and of the eight basal segments of the "Appearance in the New Forest, spasmodic." abdomen, which ends in two rather long divergent (Adams.) Colchester. setae. (Theobald.) Found at Grantchester. Fig. 3. Dilophus febrilis L. $ 4x9 mm., $5x11 mm. Abundant on Wild Parsnip, though named febrilis by Linnaeus, owing to the general opinion in Sweden that the fly resorted to houses where intermittent fever existed. Curtis states that this species causes much mischief in gardens. The so- called fever fly gets into Hop cones in Kent now and then, and causes loss by destroying their bright- ness. The larvae live in all manner of roots besides hops, and do no little damage. (Theobald.) ORTHORRHAPHA NEMATOCERA Simuliidae Fig. 4. Ova, Simulium cinereum Ltr. Fig. 5. Pupa, Simulium. Fig. 6. Larva, Simulium. Fig. 7. Habitat, Simulium. (N. D. F. P.) Figs. 4, 5, 6, 7. Simulium cinereum Ltr. Larva 4-5 mm., Pupa 4^5 mm., Ova, area, 4 mm. Habitat in the Bourn Brook, Grantchester. Sand flies are abundant in damp and sandy and marshy places, and attack man and animals as mosquitoes do. (See Typical Flies, fig. n.) ORTHORRHAPHA NEMATOCERA Psychodidae Fig. 8. Pericotna compta Eat. 2x8-5 mm. Rarely sucks blood ; larvae aquatic. Larvae of Pcricoina have 2 rows of curved veins down the body. Fig. 9. Psyclioda phalaenoides L. 12 xi. 1891. 4 mm. from tip of wing to base of abdomen. Larvae live in rotting vegetable matter and dung ; the pupae inactive, with 2 long tubes like antenna stigmata. The abdomen tapering. (Theobald.) Fig. 10. Psychoda sexpunctata Curt. 3x7 mm. On windows in April. The larvae live in dry cow- dung. They are long, subfusiform and depressed, with a slender straight cylindrical tail, longer than the preceding segment. (Figured by Bouche and M. Perrin.) (Theobald.) Grantchester. ORTHORRHAPHA NEMATOCERA Culicidae Fig. ii. Fig. 12. Figs. 11, 12, and 13. Corcthra plumicornis F. Fig. 11. (^6 mm. to end of abdomen. Fig. 12. $ 6x9 mm. Fig- 13- ? with wings closed, wings 5 mm. The larva of Corethra catches prey with its an- tennae, sweeping as do others of the Culicidae. (Figs. 11, 12, 13 micro-mounts, Waddington.) Fig. 13- ORTHORRHAPHA NEMATOCERA Culicidae f Fig. 14. Larva, Corethra. Introvert, plain. Fig. 15. Larva, Corethra. Introvert, with included air vesicle. Fig. 1 6. Larva, Corethra. Figs. 14-17. Corethra pluinicornis F. Fig. 14. Larva showing introvert 2'5 mm. from back of head to end of introvert. Fig. 15. Larva showing proboscis 3 mm. from back of head to end of proboscis. Fig. 1 6. Transparent larva, 7 mm. Fig. 17. Pupa, 7 mm. (Micro-slides, Waddington.) Fig. 17. Pupa, Corethra. ORTHORRHAPHA NEMATOCERA Culicidae Fig. 1 8. Mochlonyx vehttinns Ruthc.