ii 
The Regulative Action of Birds upon Insect Oscillations. 
cent, additional. A few Coleoptera (fifteen per cent.) of which 
one-third were carabid larvae, and three per cent, of Cjdnidae 
(. Podisus ), were the only other important elements. Anomala 
binotata (eight per cent.), Telephorus, and an undetermined long- 
horn, were the other Coleoptera. 
AMPELIDiE. Wax- wings. 
Ampelis cedrorum, V. Cedar Wax- wing. 
A flock of about thirty of these birds was repeatedly started 
in the orchard during the first visit, but none were seen in 1882 . 
Seven of the flock were shot, and the contents of their stomachs 
carefully studied. With the exception of a few Aphodii eaten 
by three of the birds in numbers too insignificant to figure in the 
ratios, the entire food of all these birds consisted of canker-worms, 
which therefore stand at an average of one hundred per cent. The 
number in each stomach, determined by actual count, ranged from 
seventy to one hundred and one, and was usually nearly a hun- 
dred. Assuming that these constituted a whole day’s food, the 
thirty birds were destroying three thousand worms a day, or 
ninety thousand for the month during which the caterpillar is 
exposed. 
HIRUNDINIDiE. Swallows. 
Petrochelidon lunifrons, Say. Cliff Swallow. 
This species was nesting in great numbers under the eaves of a 
barn at the edge of the orchard, and many of the birds were 
continually circling through the air. A single specimen was shot, 
and found to contain nothing but the very abundant scavenger 
beetle ( Aphodius inquinatus ), with about two per cent, of unde- 
termined Hemiptera. 
FRINGILLIDAC. Finches. 
Astragalinus tristis, L. American Goldfinch. 
A flock of these birds passed through the orchard, but only a 
single one was shot. No canker-worms had been eaten by it; 
but about seventy per cent, of its food consisted of undetermined 
seeds, and the remainder of a harpalid beetle. 
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