Royal Entomological Society HANDBOOKS FOR THE IDENTIFICATION OF BRITISH INSECTS To purchase current handbooks and to download out-of-print parts visit: http://www.royensoc.co.uk/publications/index.htm This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 UK: England & Wales License. Copyright © Royal Entomological Society 2013 Handbooks for the Identification of British Insects Vol. 10, Part 14 AN INTRODUCTION TO THE IMMATURE STAGES OF BRITISH FLIES DIPTERA LARVAE, WITH NOTES ON EGGS, PUP ARIA AND PUPAE K. G. V. Smith ROYAL ENTOMOLOGICAL SOCIETY OF LONDON Handbooks for the Vol. 10, Part 14 Identification of British Insects Editors: W. R. Dolling & R. R. Askew AN INTRODUCTION TO THE IMMATURE STAGES OF BRITISH FLIES DIPTERA LARVAE, WITH NOTES ON EGGS, PUPARIA AND PUPAE By K. G. V. SMITH Department of Entomology British Museum (Natural History) London SW7 5BD 1989 ROYAL ENTOMOLOGICAL SOCIETY OF LONDON The aim of the Handbooks is to provide illustrated identification keys to the insects of Britain, together with concise morphological, biological and distributional information. Each handbook should serve both as an introduction to a particular group of insects and as an identification manual. Details of handbooks currently available can be obtained from Publications Sales, British Museum (Natural History), Cromwell Road, London SW7 5BD. Cover illustration: egg of Muscidae; larva (lateral) of Lonchaea (Lonchaeidae); floating puparium of Elgiva rufa (Panzer) (Sciomyzidae). To Vera, my wife, with thanks for sharing my interest in insects World List abbreviation: Handbk /dent. Br./nsects. © Royal Entomological Society of London, 1989 First published 1989 by the British Museum (Natural History), Cromwell Road, London SW7 5BD. ISBN 0 901546 75 5 Printed by Henry Ling Ltd., at the Dorset Press, Dorchester, Dorset. Contents Page Introduction . 3 Acknowledgements . 4 Life-histories and ecology . 6 Agricultural and economic importance 11 Medical, environmental health and veterinary importance 15 Predators, parasites and pathogens. 19 Fossil larvae and pupae 21 Collecting, rearing, preservation and examination . 21 Biology and morphology of the immature stages 24 Eggs. 24 Larvae . 25 ~~ ~ Classification, nomenclature and use of keys. 30 Notes on the illustrations . 30 Key to suborders of British Diptera larvae . 32 Key to families for final stage larvae of British Nematocera . 33 Notes on families ofNematocera 35 Key to families for final stage larvae of British Brachycera . 55 Notes on families of Brachycera . 57 Key to families for final stage larvae of British Cyclorrhapha 71 Notes on families of Cyclorrhapha 76 Aschiza . 76 Schizophora 85 Acalyptratae. 85 Calyptratae 115 References. 141 F~~- !M Index 259 Introduction Knowledge of the larvae of Diptera lags far behind that of the adults. Of the 130 or so families of Diptera currently recognised in the world some 20 remain undescribed in the larval stages, including the following which occur in the British Isles: Acartophthal­ midae, Asteiidae, Camillidae, Chyromyidae, Stenomicridae, Tethinidae and Trixo­ scelidae (formerly included in the Heleomyzidae). These families are, however, included in the present handbook with suggestions as to where their larvae should be sought. Of the more than 80,000 species ofDiptera known to science probably less than two per cent have been described in the immature stages while adults of further new species are continually being described. The families known best in the larval stage are usually those of medical or economic importance (e.g. Culicidae, Tipulidae). More recently families whose larvae are of importance as ecological indicators are being systematically studied (e.g. Chironomi­ dae). For the majority of families, however, only a few species come into these categor­ ies and description of the immature stages has remained rather casual. Fortunately work on the immature stages of a particular family that occupies a distinct ecological niche has been recognised as a valuable research topic for university students working 3 for higher degrees. This has resulted in several valuable and comprehensive studies, e.g. Dixon (1960) and Hartley ( 1961) on Syrphidae; Okely ( 1974) and Pitkin ( 1988, in part) on Sphaeroceridae. Unfortunately all families do not lend themselves to concentrated short term study and may require a long and continuous effort before a reasonably comprehensive treatment can be achieved, e.g. Brindle's work on Tipulidae (1952- 1967) and the 25 years required to produce Skidmore's (1985) book on Muscidae. Some fine work has been done in Europe especially by Dusek & Laska (1967, summary) on Syrphidae, and Hennig (1943a-1956) and Schumann (1953- 1974) on Cyclorrhapha. The identification oflarvae beyond family level has thus remained a difficult process requiring a knowledge of, and access to, a very widely scattered literature. In this Handbook keys to families and sub-families of final stage larvae are given as far as this is possible. In some families further keys and illustrations are given to facilitate identifica­ tion to genera and sometimes to species. For the latter the aim has been to include species of medical and economic importance, species commonly involved in the every­ day enquiries of environmental health officers or the general public (including non­ British species regularly introduced in imported food, etc.) and those species most frequently encountered as larvae during ecological surveys or of special value in teach­ ing biology at school or university level. To further these aims some bionomic keys are given at appropriate points where a limited number of species occur in a restricted habitat. In a section on ecology there are some listings of families, genera or species to be found in specific habitats which, by restricting the possibilities, should facilitate more rapid identification by reference to the figures alone. A full index provides rapid access to ecological information in the text. There are brief general comments on eggs and pupae, and illustrations showing their diversity of form. The following comprehensive specialist works on larvae are of value in identifica­ tion. Hennig (1948- 1952) is well illustrated and lists the world species described as larvae up to that time with a full bibliography. Peterson (1957) treats Nearctic species but Teskey (in McAlpine et al., 1981) does so in much greater detail. Seguy (1950) gives much detailed information on all aspects of fly biology arranged under subject and habitat and similar information for British species is given in Stubbs & Chandler ( 1978) which includes a key to families of larvae (by Brindle & Smith). Brauns ( 1954) deals with terrestrial Diptera larvae and pupae and is well illustrated. Teskey (1984) gives a well-illustrated key to aquatic Diptera larvae. Oldroyd & Smith (in Smith, 1973) give a key to families of larvae of medical importance. Smith ( 1986) deals with species of forensic importance including those found on carrion (human and animal). Koppen ( 1972) covers some agricultural pest species. Askew (1971) and Clausen (1940) review parasitic Diptera. References to particular families are given in each section below. As this book goes to press a very important two volume work has appeared on the immature stages of the Cyclorrhapha (Ferrar, 1987) and also part 2 of the Manual of Nearctic Diptera (McAipine et al., 1987), also covering Cyclorrhapha, has been published. Acknowledgements In his Introductory Handbook to the Diptera the late Harold Oldroyd (1970b) expressed the hope that a volume dealing with the early stages of flies would eventually be produced in this series. Indeed, we had intended that we should cooperate in such a venture but his early death sadly prevented this. Nevertheless many of his ideas expressed both verbally and in his writings, especially in his unique book The Natural History of Flies (1964), have stimulated an interest in the biology of flies among Dipterists, including the present author. 4 The following colleagues working in the British Museum (Natural History) (includ­ ing those on the staff of the Commonwealth Institute of Entomology) are warmly thanked for reading appropriate sections of the work and for their constructive criticism, though they must not of course be held responsible for any inaccuracies that remain: John Boorman, John E. Chainey, Dr Peter S. Cranston, Dr Roger W. Crosskey, William R. Dolling, Dr Keith M . Harris (CIE), Dr Brian R. Pitkin, Adrian C. Pont, and Dr Ian M. White (CIE). Peter Chandler kindly checked the Mycetophili­ dae and Platypezidae and Phi! Withers checked Psychodidae. For generous permission to base some of my figures or keys on their published works (see References) I thank Dr E. J. Alien, Dr Pamela Alien, D . G. Ashby, Dr R. A . Bedding, Dr C. 0 . Berg, Dr P.A. Berry, Dr A. D. Bratt, Prof. A. Brauns, Alan Brindle, Or D . E. Bryce, Or A. E. F. Chandler, Peter Chandler, Dr Lanna Cheng, Or W. Ciampolini, Dr C. P. Clausen, Or P. S. Cranston, Or R. W. Crosskey, Dr R . Dahl, Or R. H . L. Disney, Or J . Doskocil, Prof. C. Dupuis, Or A. Draber-Monko, Or J. Dusek, C. E. Dyte, Or W. C. Eastin, Dr H . J . Egglishaw, Or B. A. Foote, Or Paul Freeman, Or A. Friedberg, Prof. P. Goeldlin, Prof. W. L. Gojmerac, J . F. Graham, Dr D . J. Greathead, Dr L. R. Guimaraes, Or K. M. Harris, Dr J. C. Hartley, Prof. Wolfgang Hennig (for the late Prof. Willi Hennig), Or D. F. Houlihan, Or C. Juliard, Or L. V. Knutson, Or N . P. Krivosheina, Or B. R. Laurence, Or A. Z . Lehrer, D . C. Lewis, Dr A. M . Lobanov, Or M. L. Luff, Dr L. Lyneborg, Dr M . E. Maldague, Or B. M. Mamaev, Or E. Mellini, Dr R . M . Miller, Or Hildegarde Miiller, Or A. Nagatomi, Or S. E. Neff, Or P. Nielsen, Or I. W. B. Nye, Prof. T. Okada, P. Osborne, Dr V. Passovici, P. I. Persson, A. Peterson, Chih Ping, Or J . Robinson, G . H . R. Rothschild, R.