The Food of Birds. 
156 
dant (fifty-eight per cent.). Grapes, the berries of sumach, 
scarlet thorn (Crataegus) and holly ( Ilex decidua ) were 
also found. Sixteen per cent, of the food was insects, of 
which the larger part (ten per cent.) was the larva of 
Harpalinae — eaten, however, by but two of the birds. 
Prominent among these w r as the larva figured and de- 
scribed by Professor Riley in the Report of the United 
States Entomological Commission for 1877, p. 290, and 
there doubtfully referred to Harpalus herbivagus. The 
remaining kinds were Geotmtipes blackburnii, Podisus 
spinosus, a single spider, and one unknown caterpillar. 
Even in the dead of winter, therefore, this bird does not 
cease its warfare on our predaceous bugs and beetles. 
Summary 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 Noctuidae, 
three per cent, of leaf-cliafers 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 C'arabidae 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., Iulidae 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 Turdidae, we find that the 
bluebird is essentially a thrush in food. From the robin 
it differs principally in the larger number of Hymcnop- 
