272 ELEMENTARY ZOOLOGY. 



only. Investigate the conditions and find an explana- 

 tion. 



9. Why is moulting necessary among the arthropods? 

 How is it accomplished? 



10. Study the habits and the life history (field or library) 

 of the following animals: hermit-crab; digger wasp; the 

 ichneumons; the lobster; the bot-fly; the May-fly; the 

 mosquito; scarab beetle; plant-lice. 



11. Insects that mimic others. 



12. Life in an ant-hill. An .account of the kinds of 

 ants and their various duties. 



13. What is meant by the following terms: ants' 

 cows; slave-making among the ants; army ants; agricul- 

 tural ant. 



14. Varieties of homes among the bees and wasps. 



15. Symbiosis among the insects. 



1 6. Modifications among the flowers, to adapt them to 

 insects. 



17. Adaptations among insects to adapt them to 

 flowers. 



1 8. Give an account of an observed instance of insects 

 pollinating flowers and the method of it. 



19. Silkworm culture: methods and value. 



20. Insects introduced from foreign countries. 



2 1 . The history of efforts to find enemies of some of our 

 insect pests. 



22. Give an account of Blastophaga and the fig culture. 



23. How do bumble bees survive the winter? 



24. What is cochineal and how produced? 



25. Give an account of the following insect pests and 

 their work : 



Gypsy moth ; codling moth ; cotton-boll weevil ; San Jose 

 scale ; cottony cushion scale ; Hessian fly ; Phylloxera ; corn 



