" DESTROYERS OF INSECT PESTS 



67 



ined. The food consisted of 42.4 per cent animal 

 food and 57.6 per cent vegetable food, divided as 

 follows : — 



Animal food 



Per cent 



Beetles 17 



Caterpillars 9 



Grasshoppers. . 5 



Flies 3 



Bees and ants. . 3 



Bugs 2 



Miscellaneous . . 3h 



Vegetable food 



Per cent 



Wild fruit 42 



Cultivated fruit 8 



Miscellaneous 7^ 



Total — 



57J 



Total. 



42^ 



The animal food included 223 kinds of insects, 

 and the vegetable food 65 kinds of wild and 10 kinds 

 of cultivated fruit. This food may be classified ac- 

 cording to its value to man in the following groups: 



To the robin s credit To the robin s discredit Neutral food 



Per cent Per cent Per cent 



Caterpillars. . 

 May beetles. 

 Grasshoppers 



Weevils 



March flies . . 



Ants 



Other insects 



9 



5.5 



5 



4 



3 



1.5 



5 



Cultivated fruit . . 

 Beneficial beetles . 



Spiders 



Bees 



Wild fruit. . . 

 Miscellaneous 



42 

 10 



Total 33 



15 



52 



Approximately one seventh of the robin's food is 

 composed of materials beneficial to man, one third 

 is composed of insects harmful to man, and about 

 one half is composed of neutral elements. 



So far more than sixty thousand stomachs, com- 

 prising over four hundred species of birds have been 

 examined by the Bureau of Biological Survey. 



