82 



FOOD HABITS OF THE GEOSBEAKS. 



Ordinarily this insect is harmless, but occasionally it attacks garden 

 and fruit crops, especially the sugar beet. Another caterpillar also, 

 the cotton cutworm {Prodenia ornithogalU, fig. 9), which attacks 

 the latter crop as well as the tomato and cotton, is devoured by the 

 blue grosbeak. Four birds, taken in the cotton fields of Texas in 



to 



May, had eat«n 9 cotton cutworms, which constituted more than 40 

 percent of their food. IVlany other caterpillars also of the same 

 family (Sphingidw), as the purslane feeder, and two moths were 

 consumed by the blue grosbeaks examined. Because of the injurious 



Fig. 38. — Purslane caterpiUar (DeilephiJu rnicafa). 



mology.) 



(From Chittenden. Bureau of Ento- 



the 



jrrosbeak is to be 



habits of these insects their destruction 1)\' 

 commended. 



The true bugs (Hemiptera) constitute another group of insects, 

 mainly injurious, and all of them eaten by the grosbeak are destruc- 

 tive. These include members of the squash-bug family (Coreidse), 

 stink-bug family (Pentatomida?), tree-hoppers (^lembracidse), and 

 cicadas or harvest flies (Cicadidae). One blue gi'osbeak from South 

 Dakota had eaten 3 of the latter, which composed 94 percent of its 

 stomach contents. 



