Medical Entomology for Students

THIRD EDITION

Arthropod vectors of human diseases, such as malaria, filariasis and typhus, are a continuing threat to human health. Since publication of the first edition, Medical Entomology for Students has proved a popular textbook by providing the reader with all the basic information on insects, mites and ticks that affect human health. It examines methods of identification, the biology and ecology of these medically important arthropods and how they can be controlled. Its clear presentation and concise writing style, with extensive illustrations and a glossary of entomological and epidemiological terms, make the book comprehensive and accessible. Each chapter concludes with suggestions for further reading.

   Medically important arthropods concern students of subjects as varied as tropical medicine, parasitology, entomology and pest control. This textbook provides essential reading for physicians, nurses, health officials and community health workers, and is recommended for both students and teachers of medical entomology courses.

MIKE W. SERVICE is Emeritus Professor of Medical Entomology at the Liverpool School of Tropical Medicine, UK. He has written over 200 research papers on medical entomology and given advice and training in the field to over 50 countries.

Medical Entomology for Students

Third Edition

Mike W. Service
Emeritus Professor of Medical Entomology,
Liverpool School of Tropical Medicine, Liverpool, UK

PUBLISHED BY THE PRESS SYNDICATE OF THE UNIVERSITY OF CAMBRIDGE
The Pitt Building, Trumpington Street, Cambridge, United Kingdom

CAMBRIDGE UNIVERSITY PRESS
The Edinburgh Building, Cambridge, CB2 2RU, UK
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http:/ /www.cambridge.org

First edition © M. W. Service 1996
© Cambridge University Press 2000, 2004

This book is in copyright. Subject to statutory exception
and to the provisions of relevant collective licensing agreements,
no reproduction of any part may take place without
the written permission of Cambridge University Press.

First edition published by Chapman and Hall 1996
Second edition published 2000
Third edition published 2004

Printed in the United Kingdom at the University Press, Cambridge

Typefaces Palatino 10/12.5 pt. and Frutiger   System LATEX 2_e   [TB]

A catalogue record for this book is available from the British Library

Library of Congress Cataloguing in Publication data
Service, M. W.
Medical entomology for students / Mike W. Service. – 3rd edn.
p.   cm.
Includes bibliographical references and index.
ISBN 0 521 54775 X (paperback)
1. Insects as carriers of disease.   I. Title.
RA639.5.S47   2004
614.4′32 – dc22   2004040659

ISBN 0 521 54775 X paperback

Every effort has been made in preparing this book to provide accurate and up-to-date information that is in accord with accepted standards and practice at the time of publication. Nevertheless, the author, editors and publisher can make no warranties that the information contained herein is totally free from error, not least because clinical standards are constantly changing through research and regulation. The author, editors and publisher therefore disclaim all liability for direct of consequential damages resulting from the use of material contained in this book. Readers are strongly advised to pay careful attention to information provided by the manufacturer of any drugs or equipment that they plan to use.

To Wednesday once again

Contents

Preface to the first edition

This is not intended as a reference book on medical entomology; those interested in such a book should consult Medical Insects and Arachnids (1993) edited by R. P. Lane and R. W. Crosskey (Chapman & Hall). The present book is aimed at students, whether they be physicians, nurses, health officials, community health workers or those studying for a masters’ degree in parasitology or medical entomology. Its aim is to provide basic information on the recognition, biology and medical importance of arthropods and guidelines for their control. In a teaching book such as this it is always difficult to decide how much detail to include and what to omit; you cannot satisfy everyone. Nevertheless I have attempted to write a book to suit the needs of most students.

   The reader should be selective. For example, I hope that most will find all, or most of, the information given in the chapters on fleas, lice, bedbugs, scabies mites and flies relevant to their needs, but I would expect readers to be more selective with some other chapters, such as those on mosquitoes. These insects are undoubtedly the most important arthropod vectors; nevertheless some students may think I have included too much detail on certain aspects for their needs, and if so they can largely disregard such bits. I have also tried to be selective and avoid giving too many references at the end of each chapter, but with some vectors this has not been easy.

May 1995

Preface to the second edition

This new edition remains largely unchanged in respect of area covered from the first edition, and I have generally kept to the same style and format. As stated in the first edition this is a student textbook on medical entomology; those interested more in reference books should consult the publications listed at the end of this Preface. I have revised the text where necessary and rewritten many of the sections on control as these can quickly become outdated. A number of new figures are included, and some previous ones have been redrawn or modified. A few of the older references under the headings ‘Further reading’ have been omitted and several new ones added. Finally I have added a Glossary, mainly entomological, that I hope will help students to understand better some of the entomological terms commonly used.

February 1999

Preface to the third edition

The philosophy remains the same, to try and present clear and concise accounts of the most relevant information on the identification, life cycles and infections transmitted by arthropods of medical importance. The text has been completely revised and updated to include most recent vector and disease control strategies and new discoveries relating to the epidemiology of disease transmission. In 2000 some mosquito species formerly in the genus Aedes were transferred to the new genus Ochlerotatus, so that for example Aedes togoi is now called Ochlerotatus togoi. Although this change will inevitably lead to some confusion, I nevertheless have used it here because the name Ochlerotatus will now be found in most of the more recent scientific literature. Not to use this new generic name would create greater confusion! Some figures have been redrawn and new ones added, as have new tables and an appendix.

   I have tried to help students during revisionary reading by placing in bold italics words relating to items, whether morphological (e.g. antennae, capitulum) or biological (e.g. transovarial, reservoir hosts), that are important in vector recognition or for understanding the role of vectors in disease transmission.

   In addition to the Further reading at the end of each chapter, there is a Select bibliography of some key publications, mostly books on medical entomology, after the Glossary.

As before, readers, whether they be physicians, community health workers, health officials, nurses, or those specializing in medical entomology or parasitology, should be selective when reading the various chapters in this book, and focus on facts and issues that are most relevant to their needs or studies. Good luck!

October 2003

Acknowledgements

I would like to thank the following colleagues and friends, arranged in alphabetical order, for their prompt responses to various questions on their specialist subjects, J. P. T. Boorman, J. H. Bryan, R. W. Crosskey, M. J. R. Hall, R. E. Harbach, C. G. Moore, A. Pont and A. Walker.

   I am indebted to the Trustees of the Natural History Museum, London for permission to reproduce Figures 4.2 and 4.4a drawn by R. W. Crosskey, and to the Museum for permission to reproduce, in a modified form, Figures 17.1 (male tick) and 19.3. I am also indebted to Blackwell Scientific Publications, Oxford, for permission to reproduce figures 1.14 and 11.5 drawn by Miss M. A. Johnson.