Guides to the Freshwater Invertebrates of Southern Africa Volume 10: Coleoptera Editors: R Stals & IJ de Moor TT 320/07 Water Research Commission Guides to the Freshwater Invertebrates of Southern Africa Volume 10: Coleoptera Editors: R Stals & IJ de Moor Prepared for the Water Research Commission December 2007 WRC Report No. TT 320/07 ii Freshwater Invertebrate Guide 10: Coleoptera x Obtainable from: [email protected] or Water Research Commission Private Bag X03 Gezina Pretoria 0031 South Africa The publication of this guide emanates from a WRC research project entitled: The Invertebrates of South Africa – Identification Keys (WRC Project No. K5/916) DISCLAIMER This book has been reviewed by the Water Research Commission (WRC) and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the WRC, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. ISBN 978-1-77005-629-9 Printed in the Republic of South Africa Cover photograph: Hygropetric habitat, Bridal Veil Falls, Chimanimani Mountains, Zimbabwe. Photographer: Koos van der Lende. Since there is a possibility that revised editions of this series of guides may be printed in the future, we welcome constructive suggestions, particularly in relation to keys used to identify various taxa. These suggestions should be submitted in writing to the Water Research Commission (address given above). All such correspondence must be marked 'For the attention of the Director, Water-linked Ecosystems, (Project K5/916/0/1)'. iii CONTENTS Preface ............................................................................................. v Acknowledgements ...................................................................... viii Geographical region covered by this guide .................................... ix About the authors and editors ......................................................... xi Chapter 1: Introduction to aquatic Coleoptera ................................. 1 R. Stals Appendix to Chapter 1: Additional Plates ..................................... 39 R. Stals Chapter 2: Myxophaga .................................................................. 45 M.H. Villet & S. Endrödy-Younga Chapter 3: Gyrinidae ..................................................................... 53 R. Stals Chapter 4: Haliplidae ..................................................................... 59 S. Endrödy-Younga & R. Stals Chapter 5: Noteridae ...................................................................... 63 S. Endrödy-Younga & R. Stals Chapter 6: Dytiscidae .................................................................... 69 O. Biström Chapter 7: Aspidytidae .................................................................. 85 I. Ribera & D.T. Bilton Chapter 8: Georissidae ................................................................... 89 S. Endrödy-Younga Chapter 9: Hydrochidae ................................................................. 93 S. Endrödy-Younga & R. Stals Chapter 10: Spercheidae ................................................................ 97 S. Endrödy-Younga Chapter 11: Hydrophilidae: Hydrophilinae ................................. 101 R. Stals & S. Endrödy-Younga Chapter 12: Helophoridae ............................................................ 113 R. Stals Chapter 13: Hydraenidae ............................................................. 117 P.D. Perkins Chapter 14: Scirtidae ................................................................... 133 S. Endrödy-Younga & R. Stals iv Freshwater Invertebrate Guide 10: Coleoptera x Chapter 15: Elmidae .................................................................... 139 H.G. Nelson Chapter 16: Dryopidae ................................................................. 153 H.G. Nelson Chapter 17: Limnichidae ............................................................. 159 S. Endrödy-Younga Chapter 18: Heteroceridae ........................................................... 163 R. Stals Chapter 19: Psephenidae ............................................................. 167 W.D. Shepard & C-F. Lee Chapter 20: Ptilodactylidae ......................................................... 173 F.C. de Moor Chapter 21: Chrysomelidae: Donaciinae ..................................... 177 E. Grobbelaar Chapter 22: Curculionidae ........................................................... 183 R. Stals Chapter 23: Collecting water beetles: an introduction ................ 193 C.R. Turner Appendix: Checklists of the known southern African taxa of Coleoptera .......................................................................... 205 R. Stals Glossary of terms ......................................................................... 231 Glossary of place names .............................................................. 247 Index of scientific names ............................................................. 251 v PREFACE This identification guide is one of a series of ten books that include keys to most of the fresh- and brackish-water invertebrates in southern Af- rica. The paucity of identification guides suitable for non-specialists has become a yawning gap in the tools available to scientists, managers and scholars concerned with the assessment and management of water re- sources. It is hoped that the present guides will be of value to these and other users, and that the environment will benefit as a result. The principal aim of this series is therefore to synthesise much of the existing knowledge on the identification of freshwater invertebrates into a standard format that is accessible to users who wish to identify taxa beyond their field of exper- tise. Identification guides tend to be perpetually out of date, particularly in terms of nomenclature, due to advances in systematics. To keep abreast with some of the changes in nomenclature, readers are referred to the checklists in The Aquatic Arthropods (Insects, Crustaceans and Mites) of South(ern) Africa (http://www.ru.ac.za/aquatalogue). There is also a possi- bility that the present series will be periodically revised, but this is contin- gent on future funding. Identification of taxa to species level is the ideal to which we would like to strive, but for a number of reasons this is not always possible: the present knowledge of taxa does not often permit such detailed identifica- tion, and in instances where taxa are well known, identification to such a fine resolution is usually constrained by space considerations and cost ef- fectiveness. In some instances, particularly for small, relatively well- researched groups such as the freshwater molluscs, taxa have however been identified to species level. Since new species are constantly being discovered, users of these guides are cautioned against attempting to 'make' unusual specimens 'fit' existing keys. Users are encouraged to in- form experts of such specimens, to take note of new distribution records, and to lodge all collections with well-known museums, particularly those that are depositories for collections of freshwater invertebrates (e.g. the Albany Museum, the South African Museum, the Transvaal Museum, and the South African National Collection of Insects). This series includes an initial introductory volume containing general information and a key to the families of invertebrates. Subsequent volumes contain keys to different invertebrate groups, most often logically clustered together but in some instances the need for cost-effectiveness has resulted in the creation of some rather uncomfortable 'bedfellows', such as the arachnids and molluscs that are combined in Volume 6. vi Freshwater Invertebrate Guide 10: Coleoptera x The books in the series are the culmination of years of effort by a large number of people and organizations: Shirley Bethune, Jenny Day, Barbara Stewart, Nancy Rayner and Maitland Seaman started the project in 1986; Jenny Day, Bryan Davies and Jackie King initiated contact with authors and began the editing process, and Barbara Stewart and Elizabeth Louw later became involved in editing the Crustacea chapters. A decade later, Chris Dickens successfully obtained funding from the Water Research Commission (WRC) for the completion of the project and later took on the job of Project Leader; Steve Mitchell managed the project from the WRC; from 1998 Jenny Day took on the role of senior scientific editor, and Irene de Moor was contracted to take on the job of managing editor. All of those above (with the exception of Nancy Rayner and Elizabeth Louw) as well as Mark Chutter, Ferdy de Moor, Lil Haigh, Arthur Harrison, Rob Hart, and Martin Villet, are part of the Editorial Board that was initially formed in 1998. The production of the Coleoptera volume has been a long and arduous process. Many obstacles have had to be overcome, particularly due to the untimely death of Sebastian Endrödy-Younga, who was to have been the editor of this book. Beetle specialists are relatively few and far between, so the loss of Sebastian was devastating. Fortunately, Riaan Stals was able to step into the breach as the main author and scientific editor. Besides being the author of numerous chapters, he has also had to update and rewrite many of the original chapters, recruit new authors and artists, compile a vast index of distribution records, and produce most of the figures in this book. It has been an exhausting and at times traumatic process, but the fi- nal product is a tribute to