IMMS' GENERAL TEXTBOOK OF ENTOMOLOGY Volume I IMMS' GENERAL TEXTBOOK OF ENTOMOLOGY TENTH EDITION Volume I: Structure, Physiology and Development O. W. RICHARDS M.A., D.Sc., F.R.S. Emeritus Professor of Zoology and Applied Entomology, Imperial College, University of London and R. G. DAVIES M.Sc. Reader in Entomology, Imperial College, University of London LONDON CHAPMAN AND HALL A Halsted Press Book John Wiley & Sons, New York First published 192.5 by Methuen and Co., Ltd. Second edition, revised, 1930 Third edition, revised and enlarged, 1934 Fourth edition, 1938 Fifth edition, 1942 Sixth edition, 1947 Seventh edition, 1948 Eighth edition, 19S 1 Ninth edition, revised by o. W. Richards and R. C. Davies, 19S7 Tenth edition published in two volumes, 1977 by Chapman and Hall Ltd., 11 New Fetter Lane, London EC4P 4EE Reprinted 1979 © 1977 o. W. Richards and R. C. Davies Filmset in 'Monophoto' Ehrhardt II on 12 pt. ISBN-13: 978-0-412-15210-8 e-ISBN-13: 978-94-011-6514-3 DOl: 10.1007/978-94-011-6514-3 This paperback edition is sold subject to the condition that it shall not, by way of trade or otherwise, be lent, resold, hired out, or otherwise circulated without the publisher's prior consent in any form of binding or cover other than that in which it is published and without a similar condition including this condition being imposed on the subsequent purchaser. All rights reserved. No part of this book may be reprinted, or reproduced or utilized in any form or by any electronic, mechanical or other means, now known or hereafter invented, including photocopying and recording, or in any information storage and retrieval system, without permission in writing from the Publisher. CONTENTS Preface page vii VOLUME I PAR T I. Anatomv and Physiology I. Introduction 3 2. The Integument I I 3. Segmentation and the Divisions of the Body 24 4. The Head and Cervix 27 5. The Thorax 42 6. The Abdomen 73 7. The Endoskeleton 81 8. The Muscular System 86 9. The Nervous System 101 10. The Sense Organs and Perception 123 I I. The Sound- and Light-producing Organs 179 12. The Alimentary Canal, Nutrition and Digestion 192 13. The Respiratory System 209 14. The Circulatory System 234 IS. The Excretory Organs, Fat-body and other Haemocoelic Structures 248 16. The Glands or Organs of Secretion 263 17. The Reproductive System 287 PAR T I I. Development and Metamorphosis 18. Embryology 323 19. Postembryonic Development 353 Index 395 Vl CONTENTS VOLUME II PAR T I I I. The Orders of Insects The Classification and Phylogeny of Insects 421 Apterygote Insects Order I. Thysanura 433 Order 2. Diplura 444 Order 3. Protura 454 Order 4. Collembola 461 Exopterygote Insects Order 5. Ephemeroptera 476 Order 6. Odonata 494 Order 7. Plecoptera 521 Order 8. Grylloblattodea 533 Order 9. Orthoptera 537 Order 10. Phasmida 563 Order I I. Dermaptera 572 Order 12. Embioptera 583 Order I3. Dictyoptera 592 Order 14. Isoptera 606 Order 15. Zoraptera 643 Order 16. Psocoptera 646 Order 17. Mallophaga 658 Order 18. Siphunculata 670 Order I9. Hemiptera 679 Order 20. Thysanoptera 782 Endopterygote Insects Order 21. Neuroptera 793 Order 22. Coleoptera 816 Order 23. Strepsiptera 922 Order 24. Mecoptera 932 Order 25. Siphonaptera 941 Order 26. Diptera 951 Order 27. Lepidoptera 1072 Order 28. Trichoptera 1161 Order 29. Hymenoptera 1175 Index PREFACE TO THE TENTH EDITION In the twenty years that have elapsed since our last complete revision of this textbook, entomology has developed greatly, both in extent and depth. There are now over 8000 publications on the subject each year (excluding the applied literature) and the difficulty of incorporating even a fraction of the more important new results has occupied us considerably. We have nevertheless retained the original plan of the book, especially as it has the merit of familiarity for many readers, but we have made a number of ap preciable changes in the text as well as innumerable smaller alterations. We have decided, with some reluctance, to dispense with the keys to families that were formerly given for most of the orders of insects. These are increas ingly difficult to construct because specialists tend to recognize ever larger numbers of families, often based on regional revisions and therefore applic able with difficulty, if at all, to the world fauna. Our revision of the text has also entailed extensive changes in the bibliographies, which have been brought more or less up to date. In doing this we have had to be rigorously selective and we have tended to give some emphasis to review articles or recent papers at the expense of older works. We recognize that this has sometimes done less than justice to the contributions of earlier authorities, but the immense volume of literature left little alternative and we apologize to those who feel our choice of references has sometimes been almost arbi trary. Every chapter has been revised in detail, many of them include new sections, and some have been extensively rewritten. In a few groups such as the Plecoptera and Heteroptera the higher classification has been recast; more often we have made smaller amendments in the number and arrange ment of families so as to bring the scheme into broad but conservative agreement with modern views. The general chapters now include some information on ultrastructure and we have retained and tried to modernize the physiological sections; as non-specialists in this field we owe a great debt to the textbooks of Wigglesworth and of Rockstein. Inevitably the book has grown in size with the development of the subject. It may, indeed, be argued that the day of the general textbook has passed and that it must be replaced by a series of special monographs. We believe, however, that there are some advantages in a more unified viewpoint and it is our hope that the new balance we have reached between the various aspects of entomology will Vlll PREFACE TO THE TENTH EDITION seem as appropriate now as the original balance was when Dr A. D. Imms' textbook was first published over fifty years ago. There are 35 new figures, all based on published illustrations, the sources of which are acknowledged in the captions. We are grateful to the authors concerned and also to Miss K. Priest of Messrs Chapman & Hall, who saved us from many errors and omissions, and to Mrs R. G. Davies for substantial help in preparing the bibliographies and checking references. London O.W.R. May 1976 R.G.D. Part I ANATOMY AND PHYSIOLOGY Chapter I INTRODUCTION Definition of the Insecta (Hexapoda) The insects are tracheate arthropods in which the body is divided into head, thorax and abdomen. A single pair of antennae (homologous with the anten nules of the Crustacea) is present and the head also bears a pair of mandibles and two pairs of maxillae, the second pair fused medially to form the labium. The thorax carries three pairs of legs and usually one or two pairs of wings. The abdomen is devoid of ambulatory appendages, and the genital opening is situated near the posterior end of the body. Postembryonic development is rarely direct and a metamorphosis usually occurs. Relationships with Other Arthropods The arthropods (Snodgrass, 1952; Clark, 1972) include animals differing widely in structure but agreeing in certain fundamental characters, some of which probably evolved convergently. The body is segmented and invested with a chitinous exoskeleton. A variable number of the segments carry paired jointed appendages exhibiting functional modifications in different regions of the body. The heart is dorsal and is provided with paired ostia, a pericardium is present and the body-cavity is a haemocoele. The central nervous system consists of a supra-oesophageal centre or brain connected with a ganglionated ventral nerve-cord. The muscles are composed almost entirely of striated fibres and there is a general absence of ciliated epi thelium. No animals other than arthropods exhibit the above combination of characters. Apart from the Insecta, the various major divisions are as follows. The Trilobita (trilobites) are an extinct group of Palaeozoic marine forms with the body moulded longitudinally into three lobes. They possess a single pair of antennae followed by a variable number of pairs of biramous limbs little differen tiated among themselves. Four pairs of these appendages belong to the head and the remainder to the trunk region. The CheIicerata include three classes, the Merostomata (king crabs), the Pycnogonida (sea-spiders) and the numerous Arachnida (spiders, scorpions, mites, ticks, etc.). The body is usually divided into cephalothorax and abdomen; the legs consist of four pairs and there are no antennae. The primitive forms respire by means of branchiae which, in the higher forms, are replaced by lung-books or 4 GENERAL TEXTBOOK OF ENTOMOLOGY tracheae. Spiracles when present are generally abdominal and consist at most of four pairs. The gonads open near the base of the abdomen and the excretory organs are usually Malpighian tubules. The presence of chelicerae, in place of sensory anten nae, and the general characters of the remaining appendages mark off the Chelicerata very definitely from all other arthropods. The Crustacea (lobsters, shrimps, crabs, barnacles, etc.) are characterized by the possession of two pairs of antennae and at least five pairs of legs. In the higher forms the body segments are definite in number and arranged into two regions - the cephalothorax and abdomen. Respiration almost always takes place by means of gills, and the excretory organs are, at least in part, modified coelomoducts usually represented by green glands or shell glands. The genital apertures are situated anteriorly, i.e. on the 9th postoral segment in some cases, up to the I4th in others. The Onychophora (Peripatus and its allies) are in some respects annectent between the annelida and arthropods, and the reasons for their inclusion in the latter are not evident from superficial examination. They are probably to be derived from primitive Annelid ancestors which had forsaken a marine habitat and become terre strial. The appendages are lobe-like structures (l6bopodia) that have become modified for locomotion on land without having acquired the jointed arthropod character. The integument is soft, though it contains chitin, and the excretory organs take the form of metamerically repeated coelomoducts. Arthropodan features are exhibited in the possession of tracheae, salivary glands, and the terminal claws to the appendages. The presence of jaws of an appendicular nature, the paired ostia to the heart, the pericardium, the haemocoelic body-cavity and the reduced coelom are further important characters allying them with other arthropod groups. The Myriapoda comprise four classes, whose members are characterized by the presence of a single pair of antennae and the absence of any differentiation of the trunk into thorax and abdomen; each segment usually bears appendages. The Diplopoda (millipedes) have the greater number of the body segments so grouped that each apparent somite carries two pairs of legs and two pairs of spiracles. The gonads open behind the 2nd pair of legs. The Pauropoda are characterized by the legs being arranged in single pairs although the terga are mostly fused in couples. The antennae are biramous and there are only twelve postcephalic segments, nine of which bear legs. The gonads open on the 3rd segment. The Symphyla have long antennae and most of the body segments bear a single pair of legs. The gonads open on the 4th postcephalic segment and there is a single pair of spiracles which are situated on the head. The Chilopoda (centipedes) are usually provided with a single pair of appendages and a pair of spiracles to each of the postcephalic segments. The first pair of legs is modified to form poison claws and the gonads open on the penultimate segment of the abdomen. Two further small groups of animals, the Tardigrada and the PentastoITlida, are placed in or near the arthropods. The Tardigrada (bear animalcules) are minute animals with a cuticle that is moulted and with four pairs of unjointed legs but devoid of antennae, mouth-appendages or respiratory organs. The gonads open into the intestine. The parasitic Pentastomida are worm-like and devoid of appendages except two pairs of hooks near the mouth. Their arthropod an affinities are mainly suggested by the larvae, which possess two pairs of clawed, leg-like processes. The phylogenetic relationships of the various arthropod groups have been much discussed and widely different theories of insect origins have been