Advances in insect physiology. V. 32 /

Cover 1
Advances in Insect Physiology 4
Contents 6
Contributors 8
Insect Immunity: An Evolutionary Ecology Perspective 10
Introduction 11
Defence via behaviour 13
The insect immune system \u2013 boundary defence 14
The Cuticle 15
The Integumental Epithelium 17
Sensilla 17
The Digestive System 17
The Spiracles and Respiratory System 18
Reproductive Tract 18
The insect immune system \u2013 haemocoelic defence 19
Clotting and Wound Closure 20
Self/Non-Self Recognition 21
Signal Transduction 23
Effector Systems \u2013 Enzyme Cascades and Cytotoxins 25
Phenoloxidase 25
Nitric oxide 25
Reactive oxygen species 26
Effector Systems \u2013 Antimicrobial Peptides 26
Effector Systems \u2013 Haemocytes 26
Ecological immunology and variation in immune defence 30
Life History Theory and The Costs of Immune Defence 31
Evolutionary cost of immune defence 32
Physiological cost of immune defence 35
Specific Relationships Between Hosts and Parasites 39
Outlook 39
Memory in Insect Immunity? 40
High Specificity, Few Receptors 40
Multiple Infections 41
Plasticity of Immune Function 42
Conclusions 42
Acknowledgements 45
References 45
Antennal Movements and Mechanoreception: Neurobiology of Active Tactile Sensors 58
Introduction 59
The antennal motor system 60
Morphological Types and Model Systems 60
Insect model systems 61
The segmented antennae of the Entognatha 61
The annulated antennae of higher insects 61
Crustacean model systems 64
Biomechanical and Kinematic Considerations 68
Kinematics, workspace and tactile acuity 68
Biomechanics of the flagellum 70
Static properties 70
Dynamic properties 72
Efferent Innervation of the Antenna 74
Muscle innervation in insects 74
Muscle innervation in crustacea 78
Physiology of Antennal Motoneurons and Muscles in Insects 79
Excitatory innervation 79
Inhibitory and modulatory innervation 81
Sensory physiology of antennal mechanoreceptors 83
Sensory Structures and Transduction 83
Mechanosensory hairs 84
Tactile hairs 84
Contact-chemosensory hairs 85
Campaniform sensilla 87
Chordotonal organs 88
Strand receptors 91
Mechanoreceptors of the crustacean antenna 91
Distribution of Mechanoreceptors 93
Hair plates 93
Campaniform sensilla 96
Chordotonal organs 98
Chordotonal organs of the scape 99
Ordinary chordotonal organs of the pedicel 99
Johnston\u2019s organ 99
Chordotonal organs in crustacea 100
Sensory hairs 101
Distribution along the flagellum 102
Considerations about functional significance 109
Physiology of Antennal Mechanosensory Neurons 109
Neuroanatomy of antennal mechanosensory and motor pathways 112
Mechanosensory Neuropils 112
Insects 112
Crustacea 116
Connections to other Parts of the CNS 118
Connections with motoneurons 119
Connections with local brain neurons 119
Antennal lobe (AL) 119
Other brain regions 119
Connections to ascending and descending neurons 120
Immunocytochemistry 122
Antennal mechanoreceptors 122
Acetylcholine 122
Serotonin 123
Nitric oxide 123
Taurine 123
Antennal motoneurons and muscles 124
Glutamate 124
Gamma-aminobutyric acid 125
Proctolin 125
Other immunohistochemical results 125
Immunohistochemistry summary 126
Antennal Motoneurons in Insects 127
General organisation 127
Are antennal motoneurons \u2018\u2018identified neurons\u2019\u2019? 127
Soma positions 128
Dendritic arborisation pattern 129
Central neurophysiology of antennal mechanoreception 131
Processing of Antennal Mechanosensory Information by Local Brain Interneurons 131
Descending Antennal Mechanosensory Interneurons 135
Behavioural physiology of the antennal tactile sense 138
Passive Sensing 139
Graviception 139
Avoidance, assistance and resistance reflexes 141
Antennal reflexes in insects 141
Reflex types in crustaceans 143
Reflex modulation in crustaceans 144
Steering of locomotion 144
Course control during flight 144
Course control during walking and running 146
Tactile elicited emergency behaviour 150
Active Sensing 152
Exploratory behaviour and tracking of objects 153
Guidance of locomotion and tactile localisation 158
Pattern recognition and learning 160
Communication 168
Agonistic behaviour 169
Transferring information about resources 172
Courtship and mating 175
Biomimetics and \u2019antennal engineering\u2019 177
Steering Insects and Robots 178
Engineering of Active Tactile Sensors 179
Conclusions 181
The Antennal Tactile Sense of Insects and Crustacea 182
Active and Passive Mechanical Sensing 183
Levels of Behavioural Complexity 185
Acronyms and abbreviations 187
Acknowledgements 188
Note added in proof 189
References 189
Eupyrene and Apyrene Sperm: Dichotomous Spermatogenesis in Lepidoptera 215
Introduction: dichotomous spermatogenesis 216
What is Dichotomous Spermatogenesis? 216
Eupyrene and Apyrene Sperm in Lepidoptera 218
Spermatogenesis in Lepidoptera 223
The Testes 223
Anatomy of the testes 223
The Verson\u2019s cell 223
Cysts 225
The blood\u2013 germ cell barrier 226
Spermatogonia 227
Spermatocytes 228
Dichotomous spermatogenesis in Lepidoptera 229
How Eupyrene and Apyrene Spermatogenesis Differ 229
The Cellular Mechanism of Apyrene Spermatogenesis 235
Failure of chromosome pairing in apyrene spermatogenesis 235
The synaptonemal complex 236
Interaction of telomeres with the nuclear envelope 237
Genetic control of chromosome pairing in meiosis 238
Duration of Eupyrene and Apyrene Divisions 239
Spermiogenesis 240
Formation of Eupyrene and Apyrene Spermatozoa 240
Peristaltic Squeezing 243
Surface Structures of Lepidopteran Sperm 244
Regulation of dichotomous spermatogenesis 245
Control of Mitosis and Meiosis 245
The timetable of spermatogenesis 245
Spermatogonial proliferation 248
Initiation of meiosis 250
Control of meiosis by ecdysteroids 251
Indirect role of ecdysteroids 254
Role of juvenile hormone 255
Similarity to oogenesis and other male reproductive systems 256
The Switch from Eupyrene to Apyrene Spermatogenesis 257
The apyrene spermatogenesis inducing factor 257
Factors within the testis that may determine apyreny 259
Co-existence of eupyrene and apyrene cysts 259
Control of Spermiogenesis 260
Control of Spermatogenesis During Diapause 262
Sperm movement and transfer 264
Release of Eupyrene and Apyrene Sperm from the Testis into the Male Tract 264
Spermiation 264
Differential release of eupyrene and apyrene spermatozoa 266
Disruption of the apyrene bundles and maintenance of eupyrene bundles 266
Circadian rhythm of sperm release from the lepidopteran testis 268
Descent of Eupyrene and Apyrene Sperm along the Male Tract 268
Sperm movement and storage in the male tract 268
Morphological changes in sperm in the male tract 269
Transfer of Eupyrene and Apyrene Sperm to the Female 271
Mating 271
Transfer of sperm during mating 272
The spermatophore 273
The number of sperm transferred 275
Sperm allocation 276
Differential transfer of eupyrene and apyrene sperm 276
Sperm Retention by Female Moths and Effects on Female Sexual Behaviour 277
Behaviour of eupyrene and apyrene sperm in the female 278
Sperm Migration from Bursa to Spermatheca 278
Dynamics of sperm movement within the female 278
The spermatophore and the source of energy for sperm migration 280
Sperm Sorting in the Spermatheca 280
Loss of Sperm from the Spermatheca 282
Sperm maturation 283
Sperm Activation 283
Acquisition of sperm motility 283
Regulation by endogenous proteases 284
Role of cyclic AMP 284
Dissolution of eupyrene bundles 286
Maturational changes in the sperm during activation 287
Other factors 291
The evolutionary rationale of dichotomous spermatogenesis 292
Evolution of Apyreny 292
Possible Functions of Apyrene Sperm 293
Conclusion 300
Acknowledgements 301
References 302
Index 318