OF EASTERN PENNSYLVANIA. 221 



Vireo flavifrons, Vieill. 



The Yellow-throated Yireo 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 

 solitaries. Like the most of its family relations, it 

 is characterized by remarkable agility, arid 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 cliptera, hymenoptera, 

 and the larvae and imagos of the smaller lepidop- 

 tera, with a small percentage of beetles and berries. 

 It feeds upon Musca domestica, Tabanus lineola, T. 

 cinctus, Cut ex tcgniorhynchns, Syrphus obliquus, S. 

 obscurus, Anthrax elongata, among diptefa; the 

 larvae and mature forms of Thecla Innnuli, Ca/li- 

 mor'pha Lecontei) Cimacodes scapha, Argynnis bel- 

 lona, Plusia prccationis, Cher r odes transvcrsata, En- 

 nonws subsignaria, Zerene catenaria, Anisopteryx 

 vcrnata, A. pomctaria, Lozoteznia rosaceana, and 

 other lepidoptera ; besides, Aphis mali, the hymen- 

 opterous forms of Apis inellijica, Megachile centun- 

 cularis, Selandria roscc, with many Andrenee and 

 Halicti, and a small number of the phyllophagous 

 coleoptera. 



