1. THE TAXONOMY OP THE BRITISH SPECIES OP CHLOROPIBAE (BIPTERA) by JOHN WALAHD ISMAY A thesis submitted for the degree of Doctor of Philosophy in the Paoulty of Science of the University of London. Royal Holloway College, Englefield Green, Egham, Surrey ProQuest Number: 10097447 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest 10097447 Published by ProQuest LLC(2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 ABSTRACT J. W. I8MAY THE TAXONOMY OP THE BRITISH SPECIES OP CHLOROPIBAE (BIPTERA). The taxonomy of the British Chloropidae is reviewed with special reference to the male postabdomen. A new secondary sexual character, the femoral comb, is found to occur in Oscinellinae. The male genitalia of each species are described and illustrated and the limits and division of genera into species groups are considered. Material collected during this study is considered together with existing material in museum and private collections and in order to stabilize the nomenclature available type specimens have been examined and interpreted. The known distribution and phenology of British species are recorded. The relationships of British Chloropidae are discussed at the interspecific and intergeneric level with reference to the world fauna. Several species are apparently undescribed and a number of species have not been recorded from Britain. The male genitalia are discussed in relation to existing generic concepts, and certain anomalies in the British genera are pointed out. The data in this thesis is related to the subfamily classification of Chloropidae, the systematic position of Chloropidae in the Biptera Cyclorrhapha and the theories of systematics in general. 3. TABLE OE CONTENTS Chapter Page 1: Introduction; figures 1-5 4 2: The maie postahdomen of Chloropidae; figs. 6-8 12 5: Peraoral comhs; Tables 1, 2; figs. 464-473 13 4: A Check-list of British Chloropidae 25 5: Introduction to Oscinellinae and Group 1 genera: Lipara, Calamoncosis, Siphonella, Eiebrigella, Polyodaspis, Siphunculina and Hapleginella 36 6: Group 2 Genera: Trachysiphonella, Aphanotrigonum, Oscinimorpha, Conioscinella, Tricimba, Tropido- scinis; Tables 5» 4» 5 56 7: Group 5 : Bicraeus; Tables 6, 7, 8 93 8: Group 4 : Gaurax 105 9: Group 5: Oscinella and Lioscinella; Table 9 108 10: Group 6: Oscinisoma, Eribolus, Elachiptera, Melanochaeta and Gampsocera; Tables 10, 11 133 11: Introduction to Chloropinae and genus groups 1 and 2: Camarota, Platycephala, Meromyza and Eurina 165 12: Groups 5-5: Cryptonevra, Lasiosina, Biplotoxa 191 15 : Groups 6-7: Eutropha and Cetema 206 14 : Group 8: Epichlorops, Melanum, Anthracophaga and Chlorops 212 15 : Group 9 : Thaumatomyia 258 16: Intergeneric Relationships of Oscinellinae; Table 12 248 17: Intergeneric Relationships of Chloropinae; Table 15 257 18: Biscussion 265 Figures 9 - 465 269 References 577 Summary 588 Acknowledgements 590 CHAPTER 1. INTRODUCTION The family Chloropidae is a medium-sized family of Schizophorous Biptera containing over 1000 species from all zoogeographical regions of the world. The following definition separates Chloropidae from other Biptera: Acalypterate Biptera which show reduction of the wing venation and chaetotaxy. Head variable in shape, with convergent postvertical setae, frontal setae absent except in Siphonellopsinae (non-British). Maxillary laciniae reduced. Frontal triangle well defined, often delimited from frons by colour or dusting. Thorax with sharp lateral margin to propleuron. Sternopleural setae absent, rarely with pleural setae. Legs without preapical setae on tibiae. Wing with costa extending to vein r^ ^ ^ or m^ ^ g Subcostal vein absent or only distinguishable at base and costal break well separated from vein r^. Anal vein absent or greatly reduced; anal cell absent. Crossvein between 2nd basal cell and discal cell absent. Male abdomen lacking terga 6 and 7* Aedeagus usually small in size and membranous apically; rarely pubescent. Hypandrium with aedeagal base connected to hypandrium wall by gonites. Female abdomen with tergite 7 divided longitudinally. Two rudimentary spermathecae, not sclerotised. Male and female genitalia symmetrical except male Siphonellopsinae (non-British). The early descriptions of Chloropidae were by Linnaeus (1758, 1761) and Bjerkander (1778) in the genus Musca. Meigen (1803) erected the first chloropid genus, Chlorops. Fallen (1820) described further species and Meigen (1830, 1838) described numerous species and several genera. JIaliday (1833) described species from British material. Fallen’s work on Scandinavian Chloropidae was continued by Zetterstedt (1838-60), while Macguart (1835) described new species and genera. Lioy (1864) and Loew (1866, 1873) erected further genera while Loew also described many species. The first comprehensive monograph of palaearctic Chloropidae was by Becker (1910), while Duda's (1932-3) volume in Die Fliegen der Palaearktischen Region is still the standard work. Collin (1952, 1939, 1946, 1966) worked mainly on British Chloropidae but never revised the Chloropinae. Smith (1965) revised the British Gaurax. In eastern Europe Nartshuk (1950- ) has produced many major revisions of palaearctic Chloropidae, many of which cover British species. Fedoseeva (I960 - ) has revised the large and difficult genus Meromyza in the eastern palaearctic region. Andersson (1963, 1966) has revised Fallen’s and Zetterstedt*s species and (1977) revised the Old World genera. The most comprehensive works on the early stages of Chloropidae are by Balachowsky and Mesnil (1935), Nye (1958) and Nartshuk (1972). Although the economically important species of Chloropidae have been studied extensively, the family as a whole has been neglected by British authors. Collin (1946) revised the British Oscinellinae and Buda (1952-3) the palaearctic Chloropidae. These papers are now out of date and are difficult to use, so that British Chloropidae are often misidentified. Moreover, a considerable number of new species have been described recently by Russian and eastern European workers: the British total of Chloropidae 6. is therefore larger than existing works would indicate. Kloet and Hincks (1945) recorded 90 species of Chloropidae, but Collin (1946) recorded 90 species of Oscinellinae. The latest edition of Kloet and Hincks (1977) includes 153 species of Chloropidae, but over 170 British species are recorded in this study, and there are almost certainly further species to be added to the list. This thesis examines the species occurring in Britain and their interrelationships, in the context of current generic concepts and of the higher classification of Chloropidae. I have not examined species unrecorded from the palaearctic region since this would have entailed considerable extra research; but the discussion of British species is relevant to the higher classification of Chloropidae in that the homogeneity of taxa is tested. The work is not intended to be a world revision of - genera, but in certain cases in the past species appear to have been misplaced. I have used the existing genera and pointed out the anomalies in the discussion. In some genera an attempt has been made to group the species into ’species groups’, a taxonomic unit which I interpret as being below the level of genus. The interrelationships of these genera may be clearer if the species groups are considered separately since some genera may not be monophyletic. New species have been included, but no manuscript names are given, and full taxonomic descriptions will be published elsewhere. In the classification of insects the first problem is the initial separation of the species. Previous authors have used colouration, but I have found this to be extremely 7. variable and wherever possible I have used morphological characters. The male genitalia have been examined to help determine the limits of the species and uncover any sibling species. I have examined available type specimens and compared them with British material with the object of stabilising the nomenclature. The terminology in this thesis is illustrated in figs. 1-8. In many respects Chloropidae show reductions in character states compared to the ground-plan condition for Biptera Cyclorrhapha (Griffiths, 1972). Andersson (1977) has discussed the morphology of Chloropidae and my terminology is similar. The cuticle of Chloropidae may have several forms of surface. It is probable (Andersson, 1977) that the ground- plan condition is a smooth, dusted cuticle. In some species (e.g. Tricimba lineela) the cuticle may be ridged or folded, but this is uncommon in Chloropidae. The dusting may be rubbed off to expose the shining surface beneath. McAlpine (1969) has shown that two distinct cuticular processes occur in Platystomatidae and other Biptera, The first of these are called microtrichia, and consist of hairs without a basal socket. Pine microsetae cause the dusting seen in Chloropidae, but the individual microsetae are too small to be seen with a binocular microscope. When a partially dusted sclerite is cleared and examined