THE INSEOTS AND ARAOHNIDS OF OANADA t%RT 1.1 The Genera Dipter?= Chironomidae r* #ffiH'y= THE INSECTS AND ARACHNIDS OF OANADA PART 1 1 The Genera of Larval Midqes of Canada Diptera' Chironomidae Donald R. Oliver and Mary E. Roussel Biosystematics Research Institute Ottawa, Ontario Research Branch Agriculture Canada l'ublication 1746 1983 @ Minister of Supply and Services Canada 1983 Available in Canada through Authorized Bookstore Agents and other bookstores or by mail from Canadian Government Publishing Centre Supply and Services Canada Ottawa, Canada KIA 0S9 Catalogue No. A 42-42-1983-llE Canada: $11.95 ISBN 0-660-11385-6 Other countries: $14.35 Price subject to change without notice Canadian Cataloguing in Publication Data Oliver, Donald R. The genera of larval midges of Canada (The Insects and arachnids of Canada, ISSN 0706-7313 ; pt. 1l) (Publication ;1746) Includes bibliographical references and index. l. Chironomidae. 2. Insects - Larvae. 3. Insects - Canada. I. Roussel, Mary E. IL Canada. Agri- culture Canada. Research Branch. III. Title. IV. Series. V. Series: Publication (Canada. Agri- culture Canada). English ; 1746. QL537.C45604 595.77'r C83-097201_3 The Insects and Arachnids of Canada Part l. Collecting, Preparing, and Preserving Insects, Mites, and Spiders, compiled by.l. E H Martin, Biosystematics Research Institute, Ottawa, 1977. Part2. The Bark Beetles of Canada and Alaska (Coleoptera: Scolytidae), by D. E. Bright, Jr., Biosystematics Research Institute, Ottawa, 1976. Part 3. The Aradidae of Canada (Hemiptera: Aradidae), by R' Matsuda, Biosystematics Research Institute, Ottawa, 1977. Part 4. The Anthocoridae of Canada and Alaska (Heteroptera: An- thocoridae), by L. A. Kelton, Biosystematics Research Institute, Ottawa, 1978. Part 5. The Crab Spiders of Canada and Alaska (Araneae: Philodromidae and Thomisidae), by C. D. Dondale and J. H. Redner, Biosystematics Re- search Institute, Ottawa, 1978. Part 6. The Mosquitoes of Canada (Diptera: Culicidae), by D. M. Wood, P. T. Dang, and R. A. Ellis, Biosystematics Research Institute, Ottawa, 1979. Partie 7. Genera des Trichoptdres du Canada et des Etats adjacents, par F. Schmid, Institut de recherches biosyst6matiques, Ottawa, 1980. Part 8. The Plant Bugs of the Prairie Provinces of Canada, by L. A. Kelton, Biosystematics Research Institute, Ottawa, 1980. Part 9. The Sac Spiders of Canada and Alaska, by C. D. Dondale and J. H. Redner, Biosystematics Research Institute, Ottawa, 1982. Part 10. The Spittlebugs of Canada, by K. G. A. Hamilton, Biosystematics Research Institute, Ottawa, 1982. Contents Introduction 7 Classification 8 o Systematic position of Canadian genera of Chironomidae . Anatomy t4 Geographic distribution l8 (]eneral biology 19 Collecting, preserving, and preparing. .. 2l 23 Acknowledements. Kev to subfamilies of larval Chironomidae . 24 Subfamily Tanypodinae 26 Key to the tribes of Tanypodinae . 27 Tribe Coelotanypodini 28 Key to the gcnera of Coelotantpoclini . 29 30 Tribe Tanypodini. ' fribe Macropelopiini. 32 JJ Key to the genera of Macropelopiini . Tribe Penraneurini. 38 Key to the genera of Pentaneurini. 38 49 Subfamily Podonominae. .. .. Kev to the tribes of Podonominae . 50 '-;r 50 I rlDe rooonomlnl . Tribe Boreochlini. 5I 5t Key to the p;enera of Boreochlini.. Subfamilv Chironominae . .. .. 54 Kev to the tribes of Chironominae . 55 j' 5r) - I rlbe (,nlronomlnl. 5l Key to the genera of Chironomini. Tribe Pseudochironomini. 9l Tribe Tanytarsini . 92 93 Key to the senera of Tanvtarsini. ' . Subfamilv Orthocladiinae. .. 100 :, , 102 Key to the qenera of Orthocladiinae. Subfamily Prodiameiinae..... 148 Key to the pJenera of Prodiamesinae . 149 Subfamily Diamesinae l5l ICJ Kev to the tribes of Diamesinae . Tribe Boreoheptagyini I 5.) 'fribe Diamesini ... r54 Key to the genera of Diamesini t55 Tribe Protanypodini 158 Subfamily Telmatogetonlnae. 159 Figures. 160 Gl,ossarv. 239 References 242 Index ' 259 lntroduction Larvae of the family Chironomidae are abundant in most freshwater and semiaquatic habitats, and in some terrestrial, brackish, and saline habitats. The red larvae found in many aquatic habitats, commonly called -I'he bloodworms, belong to this group of insects. number of species in an aquatic habitat may"comprise ouet 5O% of the total number of species of the larger invertebrates. Larval densities over 30 000/mz are not unusual. The tolal number of species occurring in Canada is probably over 2000. Despite the common occurrence of chironomid larvae in the freshwaters of Canada their taxonomy has been little studied, although recently there has been an increase in taxonomic literature about larvae (e.g., Srther 1969-80; Oliver l97lb, 1976, 1977; Oliver et al. 1978; Cairnings l9Z5; and Soponis lS77). The neglect is due partly to- the small size of many species, superficial similarity in appearance wlthln many groups, and'thi large number of species in a particular habitat. But it is ilso d.,e to the facithat microscope slide preparation and microscopic examination at high poI{'er is necessary to reveal the structural characters used in naming them. This presents the non-taxonomist with a bewilder- ing array of stirctural variarion, which is not easily handled because of the lack of taxonomic literature. Therefore an extensive section on anatomy is given to assist the non-taxonomist in identifying larvae. General sec- tio"ns on classification, biology, and collecting, preserving, and preparing are also provided. This publicarion gives keys for the identification of the last larval stage of tiZ oI the 133 genera of chironomids known to occur in Canada. tn iddition, each genui has been provided with a brief description and notes on its geographic distribution and habitat. Where.possible the keys and clescripiioti ai. based on specimens associated with adults, as the taxonomy bf chironomids is largely based on the adult male. Specimens on which this publication are based, come-primarily from ."nttul Canada, the Canadian northwest, and the islands of the Arctic Archepelago. Limited larval material was available from huge tracts of Canada r,_,ih as the Atlantic Provinces, the Prairie Provinces, British Columbia, and southern Yukon. Therefbre this publication is only an introduction to the study of Canadian chironomid larvae, as many genera and species remain to be discovered. The manuscript for this publication was cbmpleted in early 1980, but some generic name changes published since then have been included. Bilingual keys are provided and Figs. l-15 appear twice in order to show the labelinq in English and French. Classif ication The classification of chironomids at the familial and subfamilial level is confusing to the non-taxonomist. Two family names, Chironomidae and I-endipedidae, have been used. Similarly several subfamily narnes have been repeatedly interchanged; 'I'anypodinae with Pelopiinae; Chir- onominae with Tendipedinae; and Orthocladiinae with Hydrobaeninae. This instability was due primarily to two papers published by Meigen (1800, 1803). Each paper proposed a different ser of'names fbr the same insects. The earlier paper was unknor,vn for about 100 years and during this period the names proposed in the 1803 paper gained acceprance. 'f here has been much discussion about the use of' the 1800 names versus the 1803 names (see Stone 194I ; Oldroyd 1966) and it is sufficient to nore that nomenclature used in this publication is in accordance with the ruling of the International Commission on Zoological Nomenclature (see Fitt- kau 1966), which suppressed the use of the Meieen I 800 names in favor of the 1803 names. Thus Chzronomus Meiqen, 1803 and Chironominae are used in place of Tendipes Meigen. 1800 and Tendipedinae, and T'anypus and Tanypodinae in place of Pelopia and Pelopiinae. Consequently the f amily name is Chironomidae, not Tendipedidae. Although nor covered by a ruling of the International Commission on Zoological"N,rmenclature it is generally accepted that Orthocladiinae be used, nirt Hydrobaeninae. The subfamilial classification used here follor,r,s that of Brundin (1966) as modified by Sather (1977b). Seven subfamilies are recognized: 'I'anypodinae, Podonominae, Chironominae, Orthocladiinae, Pro- diamesinae, Diamesinae, and Telmatosetoninae. I Most of'the subfamilies have tribal divisions-see follorving section on Systematic position of Canadian genera of Chironomidae. Although a number of tribal names have been used in the Orthocladiinae (see Biundin 1966), none are used here. Srthe r (1977 b) has briefly reviewed the group relationships r,vithin the Orthocladiinae and suggested that until more is known about the immature and f'emale stages the subfamily should remain undivided. It should be noted that the tribe Calopsectrini (Townes lS45),widely used in North American literature, is equivalent to Tanytarsini. The generic level classification generally follows that of Hamilton et al. ( 1969). It has been modified to incorporare new informarion published between 1969 and early 1980 (Hansen and Cook 1976; Hirvenoja 1973; Roback l97l; S:ether 1969-80; and Soponis 1977). The classification of Hamilton et al. ( 1969) was based on a number of maior revisions, includ- ins those of Brundin (1956, 1966), Fittkau ( 1962), Pagast (19471, f-ownes (1945), and Wirth (1949). This classification adapted the European con- cept of small genera (Beck and Beck 1968) to the Nearctic fauna, thus dif f'ering considerably from the broader generic concepts used by North American workers (e.e., Sublette and Sublette 1965). IThe subfamilies