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 (Hulecanium 
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 (2. cary@) 
and the tulip scale (£. tudipifere), which latter sometimes seriously 
Fia. 31.—-Brown-tail moth (Huproctis 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 (Hermes), 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 enemies 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- 
