The Regulative Action of Birds upon Insect Oscillations. 11 



cent, additional. A few Coleoptera (fifteen per cent.) of which 

 one-thi|d were carabid larvae, and three per cent, of Cydnidse 

 (^PodisKs), were the only other important elements. Anomala 

 hinotata (eight per cent.), Telephorus, and an undetermined lonor- 

 horn, were the other Coleoptera. 



AMPELID^. Wax-wings. 



x\mpelis cedbortjm, 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. 



HIRUNDINIDtE. Swallows. 



Petrochelidox 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 (AphocUus inquinatus)., with about two per cent, of unde- 

 termined Hemiptera. 



FRINGILLID^. Finches. 



ASTRAGALINUS TRISTIS, L. AlIERICAN 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. 



