The Regulative Action of Birds upon Insect Oscillations. 15 



and Coleoptera to a little more than anotlier fourth. Of these, Cara- 

 bidie made four per cent., Cerambycid;e two, Rhynchophora one, 

 and Anomala binotata fourteen. 



TYRANNID^. Flycatchers. 



TyBANNUS CAROLINENSIS, L. KlISrGBIKD. 



This species was not uncommon, but only three were shot. 

 Two of these, to my surprise, were found to have eaten canker- 

 worms, which made more than a fourth of the food of the whole. 

 Five per cent, of the remainder consisted of undetermined Hem- 

 iptera, and all the balance was Coleoptera. Seven per cent, was 

 Elaterid;e, two Lampyrid;i?, and more than fifty-eight Scarabiei- 

 d;t, all Anomala except thirteen per cent, of Ap/iodius inqui7ia- 

 tus, eaten by one of the birds. 



CONTOPUS VIEENS, L. WoOD PeWEE. 



Three of these were shot, none of which had taken canker- 

 worms. Their food consisted chiefly of flies and gnats, which 

 amounted to fifty-five per cent. Thirteen per cent, of Aphodius 

 and ten per cent, of Ips, with a few ants and other Hymenoptera, 

 are also worthy of mention. 



Empidonax tkailli, Aud. Traill's Flycatcher. 



Two specimens, shot in 1882, had eaten only insects, one-fourth 

 of which were canker-worms, and one-third Ichneumonidas. 

 Another fourth consisted of Coleoptera, nearly half of which 

 were Anomala; and ten per cent, were ants and other Hymenop- 

 tera. 



Empidonax flaviventris, Bd. Yellow-bellied Flycatcher. 



A single specimen had eaten a number of Lepidoptera and 

 their larvie, but no canker-worms. Half the food was Coleoptera, 

 nearly all Aphodius and Anomala binotata., — fifteen per cent, and 

 twenty-five per cent, respectively. The little Psenocerus was 

 likewise taken by this bird, and a specimen of Hymenarcys 

 (Hemiptera). 



