82 BULLETIN" 621, U. S. DEPARTMENT OF AGRICULTURE. 
the most destructive pests are at their lowest ebb. A little later, 
nestling crows appear on the scene, outnumbering their parents two 
to one, and assist in the work of destruction. Not only do the young 
birds eat a much larger proportion of insect food than do their 
parents at the same time of year, but the quantity of food required 
to develop their rapidly growing bodies is considerably greater. 
That injurious insects greatly outnumber beneficial insects in the 
diet of the crow will be seen from the following review of the four 
most important orders : 
Beetles. — The crow's relation to beetles is all that the frugal agri- 
culturist could desire. Foremost among these insects in its food are 
May beetles and their destructive larvae, white grubs. These, with a 
few other phytophagous scarabaeids and scavengers of the same 
family, as disclosed by stomach examination, totaled over half the 
beetles eaten. The destruction of a few click beetles, weevils, and 
wood-boring beetles also must be considered in the bird's favor. 
Ground beetles^ most of which are beneficial, made up about a fifth 
of the beetle food and must be charged against the crow. Copropha- 
gous and necrophagous forms eaten, as Silphidee and Staphylinidse, 
are slightly beneficial. 
Grasshoppers. — In its consumption of grasshoppers the crow ren- 
ders man its most important service. In regions where these de- 
cidedly injurious insects are abundant their nymphs form the prin- 
cipal insect-food of nestlings. Not only do the food habits of these 
young birds exert a strong control on the increase of grasshoppers, 
but the destruction of these insects is accomplished so early in the 
season that it has the added effect of preventing much of the damage 
which would be inflicted if the work were delayed till later in the 
year. 
Caterpillars. — In its consumption of caterpillars the nestling crow 
exceeds its parent in effectiveness in the ratio of about ± to 1. This 
food, found in over a third of the stomachs of young crows, is all 
in the bird's favor, especially since cutworms constitute the major 
portion. 
True bugs. — Among the true bugs, only soldier bugs (Penta- 
tomidse) and the periodical cicada, are worthy of mention in this 
summary. The former, taken in small quantities on numerous occa- 
sions, embrace both predacious and herbivorous species^ an indis- 
criminate destruction of which must be largely neutral in effect. The 
destruction of the periodical cicada must also be considered of minor 
economic importance. 
Spidees. 
The exact economic status of the large wolf spielers (Lycosidae), 
which comprise the major part of the arachnid food of young crows, 
