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 (Sphingide), as the purslane feeder, and two moths were 
consumed by the blue grosbeaks examined. Because of the injurious 
Fic. 38.—Purslane caterpillar (Deilephila lineata). (From Chittenden, Bureau of Ento- 
mology.) 
habits of these insects their destruction by the erosbeak is to be 
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 (Coreide), 
stink-bug family (Pentatomide), tree-hoppers (Membracidee), and 
cicadas or harvest flies (Cicadide). One blue grosbeak from South 
Dakota had eaten 3 of the latter, which composed 94 percent of its 
stomach contents, 
