Rhabdophaga heterobia, 70

Riley, C.V., 83

Sanderson, E.D., 17

Sand-midges, 78

Sarcophaga, 91

Saw-flies, 58-9

Scale-insects, 20.
  See also Coccidae

Scarabaeidae, 52

Schmidt, E.O., 21

Scolytidae, 55

Scudder, S.H., 106

Seasonal changes, 89-104

Seasonal dimorphism, 102

Semi-pupa, 118

Sesiidae, 62

Sexual differences, 15, 20-1, 90

Sharp, D., 13, 36, 40, 115

Silk-spinning, 58, 62-3, 82

Silkworms, 82

Silpha, 50

Siltala, A.J., 63

Silvestri, F., 119

Simulium, 78, 87

Smith, J.B., 17

Sphegidae, 66-7

Sphingidae, 60

Spinneret, 58

Spiracles, 2, 23, 70, 72, 77, 86, 87

Spring-tails, 11

Stone-flies, 24, 107, 110

Sub-imago, 33, 117

Sucking insects, 17

Swammerdam, J., 33

Syrphus, 74-6

Tachininae, 73, 91

Tenebrio molitor, 119

Termitoxeniidae, 92

Theobald, F.V., 100

Thysanura, 11

Tiger Moths, 59, 82, 98

Timber-beetles, 54

Tineidae, 62

Tipulidae, 70

Tortoiseshell Butterfly, 45, 95

Tortricidae, 62

Tracheal system. See Air-tubes, Spiracles

Transformation. See Metamorphosis

Triassic insects, 107

Trichocera, 70

Trichoptera, 62-3, 76, 80, 86

Tsetse Flies, 91

Turnip-fly, 53, 92, 94

Turnip Moth, 98-9

Tussock Moths, 90, 97

Vanessa urticae, 45, 95

Van Rees, J., 42

Vapourer Moth, 96-7, 115

Velia currens, 116

Verhoeff, K.W., 11

Vermiculiform larvae, 67, 71-6, 111

Virgin stem-mothers, 18

Viviparous reproduction. See Birth

Wagner, N., 90

Warble-fly, 73-4, 89, 108

Warning coloration, 60

Wasmann, E., 92

Wasps, 46, 64, 66-7, 83

Water-insects. See Aquatic insects

Weevils, 55

Weismann, A., 38, 42, 102

White Butterflies, 41, 83, 85, 100-3

Willow-beetles, 53

Wingless insects, 15, 18, 20, 96, 115

Wing-rudiments, 13, 18, 20, 22, 24, 28, 33, 36-8, 40, 111, 115, 117-19

Wings, 1, 14, 115, 119-20

Winter broods, 102-3

Wintering stages, 93-101

Wireworms, 52, 93

Wood-wasps, 65

CAMBRIDGE:  PRINTED BY JOHN CLAY, M.A.  AT THE UNIVERSITY PRESS