OF EASTERN PENNSYLVANIA. 221 



Vireo flavifrons, Vieill. 



The Yellow-throated Vireo is less abundant 

 according to our experience than the one last de- 

 scribed. It makes its appearance during the last 

 of April, or the beginning of May, and confines its 

 foraging to the tall tree-tops in retired places, 

 generally in high woods, seldom visiting the habi- 

 tation of man. It is more shy than even the Vireo 

 solitarius. Like the most of its family relations, it 

 is characterized by remarkable agility, and is a 

 busy gleaner among the leaves for insects, which 

 it also secures after the fashion of the Muscicapi- 

 dce. 'Unlike the Kinglets it is a more careful 

 nsect-hunter, thoroughly searching one tree before 

 leaving it for another. 



Its food consists chiefly of diptera, hymenoptera, 

 and the larvae and imagos of the smaller lepidop- 

 tera, with a small percentage of beetles and berries. 

 It feeds upon Musca domestica, Tabahus lineola, T. 

 cinctus, Cmex tceniorhynchiis, Syrphus obliquus, S. 

 obscurus, Anthrax elongata, among diptera; the 

 larva* and mature forms of Thecla humuli, Calli- 

 mosp/ia Lecontei, Cimacodes scapha, Argynnis bel- 

 lona, Plusia precationis, Choerodes transversata, En- 

 nomos subsignaria, Zcrene catenaria, Anisopteryx 

 vernata, A. pometaria, Lozotcenia rosaceana, and 

 other lepidoptera ; besides, Aphis mali, the hymen- 

 opterous forms of Apis mellifica, Megachile cenlun- 

 cularis, Selandria roscc, with many Andrence and 

 Halicti, and a small number of the phyllophagous 

 coleoptera. 



