156 The Food of Birds. 



cent.). Grapes, the berries of sumach, scarlet thorn (Cra- 

 tfiegus) and holly {Ilex deeldua) were also found. Sixteen 

 per cent, of the food was insects, of which the larger part 

 (ten per cent.) was the larva of Harpalinge, — eaten, how- 

 ever, by but two of the birds. Prominent among these was 

 the larva figured and described by Professor Riley in the 

 Report of the United States Entomological Commission 

 for 1877, p. 290, and there doubtfully referred to Harpa- 

 lus herhivagus. The remaining kinds were Geotrupes 

 hlackhurnii., Podisus spinosus^ a single spider, and one un- 

 known caterpillar. Even in the dead of winter, therefore, 

 this bird does not cease its warfare on our predaceous bugs 

 and beetles. 



S u m m ary for the Year . 



To these figures, giving the averages for all the months 

 mentioned taken together (except October), I invite spe- 

 cial attention. Being derived from a much larger number 

 of specimens than any of the monthly averages, they are 

 much less likely to be affected by accident or error. 

 They give, furthermore, the basis for an estimate of the 

 total effect of the bird, year after year ; and from this we 

 should be able to predict the probable effect of a destruc- 

 tion or diminution of the species. 



Taking up first the injurious insects destroyed, we find 

 that these include twenty-six per cent, of Lepidoptera, 

 nearly two-thirds of which were recognized as Noctuidm^ 

 three per cent, of leaf-chafers and twenty-one per cent, of 

 Orthoptera — a total of fifty per cent, on this side of the 

 account. On the other hand, the ichneumons amount to 

 three per cent., the Oarabidse to seven per cent., soldier- 

 beetles to one per cent., soldier-bugs to three per cent, 

 and spiders to eight per cent. — a total of twenty-two per 

 cent, of predaceous and parasitic forms. Other elements 

 are ants four per cent., Diptera only a trace, Aphodii six 

 per cent., lulidse one per cent, and vegetable food thirteen 

 per cent. The edible fruits amount only to about one per 

 cent, of the food of these one hundred and eight speci- 

 mens. Comparing with the Turdida?, we find that the 

 bluebird is essentially a thrush in food. From the robin 



