ROSEBREAST VS. SCALE INSECTS. 



53 



fruits, are most seriously affected, while shade and forest trees also 

 suffer greatly. 



Thirty-three of the rosebreasts examined had eaten scale insects, 

 four kinds of which were identified. The plum scale (Eulecannim 

 cerasifex), which is an occasional pest on cherry, apple, and pear, 

 besides the tree from which it is named, seems to be relished. A 

 female grosbeak collected in Indiana in May had consumed 36 plum 

 scales, which constituted 95 percent of its food. Of two birds from 

 Illinois, one ate 45 and the other more than 100 scales of this species, 

 which composed 95 and 100 percent, respectively, of their stomach 

 contents. Two nearly related species, the hickory scale (E. caryce) 

 and the tulip scale (E. tulipiferce) , which latter sometimes seriously 



Fig. 31. — Brown-tail moth (Euproctis chrysorrhoea). (From Howard, Bureau of Ento- 

 mology.) 



injures shade trees, also are devoured. Eleven grosbeaks ate uni- 

 dentified species of the same genus of scale insects ; two preyed upon 

 the oak scale (Kermes), while the stomachs of 15 birds contained 

 scale remains which defied determination. 



The fact that birds exert a restrictive influence upon scales has re- 

 mained almost unknown, these small insects being considered well 

 protected from feathered enemiies by their minute size and waxy 

 secretions. Hence little attention has been paid to the subject, and 

 the accounts of a few writers who announced the true relations of 

 birds to scales were overlooked or ignored. Recent investigations 

 have shown that many of our birds eat scales* The rose-breasted gros- 

 beak is prominent among them, both because it eats a maximum num- 



