42 A GUIDE FOR THE STUDY OF ANIMALS 



19. The work of birds in helping to keep the number of 

 harmful insects down. 



20. A spraying table showing what poisons are used, 

 when and for what plants and insects. 



21. The principal beneficial insects and the ways in 

 which they are beneficial. 



Special Topics 



Much of the information called for by the topics below 

 may be obtained from United States and state government 

 bulletins. Most of these may be obtained free from the 

 Department of Agriculture and from various state agricul- 

 tural colleges, while others may be obtained by purchase 

 at a nominal price. 



Orthoptera. i. Locust migrations and their cause. 



2. The locust plagues of the " great plains." 



3. Crickets and their " songs." 



Hemiptera. 4. The fight against the orange scale of 

 California. 



5. History of the introduction and spread of the San 

 Jos6 scale bug and the efforts to find a natural enemy. 

 How people fight the pest. 



6. Aphids. 



7. Relations of ants and aphids. 



8. Phylloxera and its work. 



9. The methods of fighting the chinch bug. 



10. Scale bugs. 



11. Cochineal bug and the lacs. 



Coleoptera. 12. The carrion beetle and its peculiar 

 habits. 



13. Fireflies. 



14, Egyptian scarabs. 



