Springtails (collembola) are the most common insects in terrestrial ecosystems. This work reviews the biology of the group and covers the insects classification, behaviour, physiology, evolution and response to pollution. A list of collembola genera is included along with more than 2500 references. 1 General introduction 1(7) 1.1 Overview 1(1) 1.2 key facts about Collembola 2(3) 1.3 Ecological importance 5(1) 1.4 Background reading 6(2) 2 Review of the literature on springtails 8(11) 2.1 Introduction 8(1) 2.2 Publications before Systema naturae of Linnaeus (1758) 8(4) 2.3 Linnaeus (1758) to Lubbbock (1873) 12(2) 2.4 Lubbock (1873) to Salmon (1964) 14(5) 3 Evolution, systematics and biogeography 19(27) 3.1 Introduction 19(1) 3.2 Evolution of Collembola 19(7) 3.3 Systematics of the Class Collembola 26(2) 3.4 Families of Collembola 28(14) 3.5 Biogeography 42(4) 4 Ecomorphology and anatomy 46(27) 4.1 Introduction 46(1) 4.2 Morphology 47(11) 4.3 Internal anatomy 58(6) 4.4 Sense organs 64(6) 4.5 Structure and function of the `spring' 70(3) 5 Taxonomic methods and the species concept in Collembola 73(25) 5.1 Introduction 73(1) 5.2 Methods of defining species 74(11) 5.3 Problems of defining species boundaries 85(8) 5.4 The Subfamily Onychiurinae 93(3) 5.5 Conclusions and recommendations 96(2) 6 Interactions between Collembola and the abiotic environment 98(15) 6.1 Introduction 98(1) 6.2 Temperature 99(4) 6.3 Water and salt balance 103(6) 6.4 Gaseous exchange and metabolism 109(4) 7 Interactions between Collembola and the biotic environment 113(20) 7.1 Introduction 113(1) 7.2 Feeding behaviour 113(10) 7.3 Interactions between Collembola and other animals 123(4) 7.4 The roles of Collembola in decomposition processes 127(2) 7.5 Collembola as pests 129(4) 8 Reproduction, development and life histories 133(25) 8.1 Introduction 133(1) 8.2 Reproductive organs, gametes and chromosomes 134(2) 8.3 Mating behaviour and oviposition 136(6) 8.4 Embryology 142(8) 8.5 Postembryonic development and life histories 150(3) 8.6 Ecomorphosis, epitoky and cyclomorphosis 153(3) 8.7 Parthenogenesis and sex ratios 156(2) 9 Ecology and conservation 158(25) 9.1 Introduction 158(1) 9.2 Observation and sampling techniques 158(2) 9.3 Distribution of Collembola in space and time 160(13) 9.4 Collembola as ecological indicators 173(5) 9.5 Conservation 178(2) 9.6 Cave Collembola 180(3) 10 Ecotoxicology 183(19) 10.1 Introduction 183(1) 10.2 Laboratory toxicity tests with Collembola 183(6) 10.3 Risk assessment 189(3) 10.4 Effects of chemicals on Collembola in the field 192(4) 10.5 Assimilation of chemicals by Collembola 196(4) 10.6 Evolution of genetic resistance to chemicals 200(1) 10.7 Conclusions 201(1) Appendix A World genera of Collembola 202(19) Appendix B Regional checklists of Collembola 221(5) Appendix C Laboratory and field studies on the effects of chemicals on Collembola 226(6) References 232(91) Subject index 323(3) Systematic index 326