INSECTS IN RELATION TO OTHER ANIMALS 289 
quail and prairie hen, enormous numbers. Even shore birds, 
such as geese, ducks, gulls and pelicans came to share in the 
feast. Aughey estimated that the locusts eaten in one day by 
the passerine birds of the eastern half of Nebraska were 
sufficient to destroy in a single day 174.397 tons of crops, 
valued at $1,743.97. 
Weed and Dearborn state that, of Hemiptera, Jasside are very 
often found in the stomachs of birds, and that aphids and their 
eges form a large part of the food of many of the smaller birds, 
such as the warblers, nuthatches, kinglets and chickadees. 
“ A large proportion of the caterpillars of the Lepidoptera are 
eagerly devoured by birds, forming an important element of 
the food of many species.” The hairy caterpillars are eaten 
by cuckoos and blue-jays and the large saturniid caterpillars, 
such as cecropia and polyphemus, by some of the hawks.  AlI- 
most all kinds of Coleoptera are food for birds, but especially 
the grubs of Scarabzeide, which are eagerly devoured by 
robins, blackbirds, crows and other birds. Of the Diptera, 
Cecidomyiidee and other gnats are eaten by swallows, swifts 
and night hawks; while Tipulidze are often found in the stom- 
achs of birds. Among Hymenoptera, ants are eaten exten- 
sively by woodpeckers, catbirds and many other species, as are 
also Ichneumonidze and other parasitic forms—these last by 
the flycatchers in particular. 
The Regulative Action of Birds upon Insect Oscilla- 
tions.—The worst injuries by insects are done by species that 
fluctuate excessively in number as the result of variations in 
those manifold forces that act as checks upon the multiplica- 
tion of the species. 
In order to determine whether birds do anything to reduce 
existing oscillations of injurious insects, Professor [forbes 
made some admirable studies upon the food of birds which 
were shot in an Illinois apple orchard which was being ravaged 
by canker-worms. In this orchard, birds were present in 
extraordinary number and variety, there being at least thirty- 
five species, most of which were studied by Forbes, from 
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