INJURIOUS INSECTS EATEN BY THE BLACKHEAD. 71 



wireworms, were devoured by 30 black-headed grosbeaks, but con- 

 stitute only 0.77 percent of the food. Weevils also are sparingly 

 consumed, which is in contrast to the avidity shown for them by 

 most insect-eating birds. Twenty-five of the present collection of 

 blackheads obtained specimens of these queer snouted beetles, but 

 they compose less than 1 percent of the subsistence. 



Bronzy wood-borers (Buprestida^ were captured by 8 grosbeaks, 

 pine-feeding species being identified. Lamellicorn beetles (Scara- 

 bseidse) fell a prey to 10 birds, but no important species were 

 secured. A few blackheads obtained representatives of other coleop- 

 terous famlies, such as rove-beetles (Staphylinida>), darkling beetles 

 (Tenebrionidse), and whirligig beetles (Gyrinidse), one of which 

 was found in a single stomach, though how the bird secured this 

 aquatic species is a mystery. A quick tiger-beetle {C'windela) also 

 was found in a single stomach, and hence, although beneficial, it 

 may be passed by without comment. 



Coleopterous larvae were eaten by 7 birds, 2 of which had secured 

 representatives of the family Nitidulida^. As these larvae are too 

 minute to have been eaten intentionally, and since they feed on decay- 

 ing fruit, their presence among the stomach contents shows that the 

 grosbeak also sometimes eats decayed fruit. Some of the fruit pulp, 

 therefore, which could not be identified, but which was provisionally 

 reckoned against the bird, is thus j)roven to have no value. 



Grasshoppers, which are eaten by birds almost universally, are 

 neglected by this species, as they are also by the rose-breasted gros- 

 beak. Only 7 of the 226 blackheads examined had eaten them, and 

 they constitute only 0.25 percent of the subsistence. Nevertheless, 

 the black-headed grosbeak is included among the enemies of the 

 Rocky Mountain locust by Samuel Aughey, wdio examined 2 speci- 

 mens, one of which had eaten 8, the other 17 locusts. 



Notwithstiinding the blackhead is rather whimsical about a grass- 

 hopper ration, it shares the taste of most other birds for caterpillars, 

 and it devours them and their chrysalids to the extent of 9 percent 

 of its food. Spines and hairs, popularly supposed to be abhorred by 

 birds, do not deter the blackhead, and sometimes all that is left in the 

 stomach to tell of the capture of caterpillars is a mass of thorns and 

 spines. Exactly 100 black-headed grosbeaks fed upon lepidopterous 

 insects, 70 of them choosing caterpillars and 30 cocoons and chry- 

 salids. It is among remains of the latter that we find representa- 

 tives of the most important species in the order — the codling moth 

 (fig 34). This pest is said to cause a loss of not less than $10,000,000 

 annually to the fruit growers of the United States. Inasmuch as the 

 insect has no important parasites, its feathered enemies should be 

 all the more appreciated, and it is safe to say that, with the ])robable 

 exception of woodpeckers, the blackhead is the equal of any of them. 



