LIST OF ILLUSTRATIONS 



Stages in the Transformations of a Gnat Frontispiece 



PAGE 



1. Stages of the Diamond-back Moth (Plntella 



cruciferarum) 3 



2. Head of typical Moth . . . .* . 5 



3. Head of Caterpillar 5 



4. Common Cockroach (Blatta orientalis) . . 12 

 "). Nymph of Locust (Schistocera americana) . 13 



6. Aphis pomi, winged and wingless females . 19 



7. Mussel Scale-Insect (Mytilaspis pomorum) . 21 



8. Emergence of Dragon-fly (Aeschna cyanea) . 29-31 



9. Nymph of May-fly (Chloeon dipterum) . . 33 



10. Imaginal buds of Butterfly .... 39 



11. Imaginal buds of Blow-fly .... 43 



12. Carrion Beetle (Silplid) and larva ... 51 



13. Larva of Ground-beetle (Aepus) ... 52 



14. Willow-beetle (Phyllodecta) and larva . . 53 



15. Cabbage-beetle (Psylliodes) and larva . . 54 



16. Corn Weevil (Calandra) and larva ... 55 



17. Ruby Tiger Moth (Phraymatobia fuliginosa) . Gl 



18. Larvae and Pupa of Hive-bee (Apis mellifica) . 65 



19. Larva of Gall-midge (Contarinia nasturtii) . 68 



20. Crane-fly (Tipula oleracea) and larva . . 69 



21. Maggot of House-fly (Musca domestica) . . 71 



22. Ox Warble-fly (Hypoderma bovis) with egg, larva, 



and puparium 75 



23. Pupa of White Butterfly (Pieris) ... 85 



