16 BULLETIN 621, U. S. DEPARTMENT OF AGRICULTURE. 
beetles of the genus Aphodius, so abundant in spring and fall. The 
function, of most of these beetles is that of scavengers, though one 
species, A. granarius, has been known to feed on and injure corn. A 
crow collected in California in February had eaten 50 of these. In 
view of their abundance, it is not surprising that upward of a score 
of these small beetles were frequently found in single stomachs. 
Members of the genus Atcenius, which live in rich earth, appeared less 
frequently than Aphodius. Tumblebugs (Canthdn and Geotrupes) 
often form a considerable portion of the stomach contents, and asso- 
ciated with them frequently are the remains of other scavengers, 
Copris, Onthophagus, or the brilliantly colored Phanceus carnifex. 
While it can not be said that the crow is aiding man by consuming the 
scavenger scarabseids, unless it be in case of some species possessing 
herbivorous habits, as Aphodius granarivs, it is doubtful whether it 
is doing serious harm. Feeding on these beetles may well be consid- 
ered to have a neutral effect. 
Carabidje (ground beetles). — Only recently has anything like a 
fair value of predacious beetles been recognized, and economic en- 
tomologists are depending more and more on them in battling with 
insect pests. A most striking example of the effective work of 
predacious carabids is found in the activities of the larva of the im- 
ported Calosoma sycophanta, a foe of the gipsy moth in New Eng- 
land. When it is considered that carabid beetles, including members 
of such a highly beneficial genus as Calosoma^ are frequently eaten 
by crows, a study of this portion of the food becomes of the utmost 
importance. It must be borne in mind, however, that certain ground 
beetles, as Agonoderus pallipes and a few members of the genera 
Amara and Anisodactylus^ to some extent are herbivorous and have 
been known to do appreciable damage. 
Ground beetles constituted 1.56 per cent of the yearly food of the 
adult crows examined, the bulk of these insects being taken in the 
months from April to September. May, with 5.54 per cent, was the 
month of greatest consumption, and June, with 3.24, stands next. 
In the fall and winter months these beetles did not form so much 
as 1 per cent of the food. Eeference to the tabulation on page 43 
will show that the monthly percentages of these insects eaten well 
represent their relative abundance at different seasons of the year. 
While fragments of carabids were found in a great number of stom- 
achs, only rarely did they occur in numbers or constitute a large pro- 
portion of the food, the exceptional stomachs coming mainly from the 
West, where many of the smaller and apparently herbivorous species 
are extremely common. 
The caterpillar hunters (Calosoma spp.) are probably the most 
conspicuous and valuable carabids eaten by the crow. Both adults 
