72 



FOOD HABITS OF THE GROSBEAKS. 



The codling moth is accessible to the grosbeak in two stages of its 

 developmentj namely, when the larvae are seeking a place to hibernate 

 or pupate, as the case may be, and when they are in the chrysalis 

 stage. By no means all of the birds examined had access to the 

 species, yet 25 were successful in finding the pupae or larvae, and 

 secured from 1 to 29 individuals, averaging about 5 each. It ap- 

 pears, therefore, that the grosbeak makes good use of its limited op- 

 portunities, and we agree with Professor Beal "^ that the " bird that 

 helps to destroy this * * * insect, the curse of * * * apple 

 culture, will be hailed as a blessing in spite of any shortcomings it 

 may have." 



Second in importance only to the above pest are cankerworms. 



Fig. 34. Codling moth {Carpocapsa pomonella). (From Simpson, Bureau of Entomology.) 



The spring cankerworm (Paleacrita vernata, fig. 35), which is re- 

 sponsible for a great deal of damage in apple orchards, constitutes 6 

 percent of the grosbeak's food in May. While this amount is not 

 large, it is nevertheless worthy of note, since all of it is consumed 

 when the earliest broods are developing. 



Only one other order, of insects contributes largely to the sub- 

 sistence of the black-headed grosbeak — ^the true bugs, Heteroptera- 

 Homoptera. Among minor items of the order the Heteroptera col- 

 lectively form 1.05 percent of the diet, plant bugs, together with 

 members of the squash-bug and stink-bug families and unidentified 

 forms, being eaten by 18 birds. A miscellaneous assemblage from 



"Yearbook Dept. Agr., 1904, p. 248. 



