82 



FOOD HABITS OF THE GROSBEAKS. 



Ordinarily this insect is harmless, but occasionally it attacks garden 

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

 the cotton cutworm (Prodenia ornithogalli, 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 

 May, had eaten 9 cotton cutworms, which constituted more than 40 

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

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

 consumed by the blue grosbeaks examined. Because of the injurious 



Fig. 38. — Purslane caterpillar (Deilephila Hneata). 



mology.) 



(From Chittenden, Bureau of Ento- 



grosbeak is to be 



habits of these insects their destruction by the 

 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 (Pentatomidse), tree-hoppers (Membracidse), and 

 cicadas or harvest flies (Cicadidse). One blue grosbeak from South 

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

 stomach contents. 



