The Regulative Action of Birds upon Insect OftciUations. 9 



birds had eaten Psenocenis'supernotatns^ amounting to four per 

 cent, of the food, and the other Coleoptera were scattered through 

 the families Carabidse, Nitidulidas, Scarabgeida^, Elateridje and 

 Calandridje. The Hemiptera were represented, by trivial numbers 

 of four families, including a few chinch bugs. 



MNIOTILTID^. Warblers. 



Helmixthophaga peeegrixa, Wils. Tennessee Warbler. 



A single specimen of this little warbler was taken in 1882. 

 Four-fifths of its food consisted of canker-worms, and all the 

 remainder of a single species of beetle {TelepJiorus bilineatus). 



Dendrceca estiva, Gmel. Summer Yellow Bird. 



This bird, common every where at this season, was also abund- 

 ant in the orchard. Five specimens were shot in all. The food 

 was insects, excepting six per cent, of spiders. Two-thirds of 

 the total amount eaten by all of the birds consisted of canker- 

 worms. Coleoptera were twenty-three per cent, of the whole 

 amount, six per cent, being Aphodius, and twelve per cent. 

 JPsenocerus supernotatus\, already 'frequently mentioned. Carab- 

 idae and Calandridse were represented by insignificant ratios, and 

 Lampyridaj by a single Telephorus eaten by one of the birds. 

 One per cent, of Hemiptera, and two of Hymenoptera complete 

 the record. 



Dendrceca pennstlvanica, L. Chestnut-sided Warbler. 



Two specimens of this abundant migrant were shot in the 

 orchard in 1882. Like the preceding warbler, two-thirds of their 

 food consisted of canker-worms, and an additional ten per cent. 

 of other caterpillars. A few ants were eaten by both of the birds. 

 Eleven per cent, of Coleoptera, likewise eaten by the two, was 

 about equally divided between some undetermined Scarabseidse 

 and Psenocerus supernotatiis. One of the birds had eaten plant- 

 lice, which amounted to five per cent, of the food; and both had 

 taken ants to the amount of six per cent. 



Dendrceca striata, Forst. Black-poll Warbler. 



Four of these birds were shot in 1882. Some undetermined 

 seeds found in the crop of one of them reduced the insect ratio 



