﻿FOOD HABITS OP THE VIEEOS 



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weevils, which form almost a fourth (24.82 per cent) of the totaL 

 The beneficial beetles eaten are almost all of the family Coccinellidaey 

 or ladybirds, well-known as enemies of plant lice and scale insects. 

 Thirteen species of ladybirds have been identified from stomachs of 

 the Philadelphia vireo, and these make up a little more than a fifth 

 of all the beetles consumed, or about 5 per cent of the total food. 

 This large percentage, however, is more than offset by the remaining 

 beetles most of which are species of distinctly injurious tendencies. 

 The leaf-eating beetles ( Chrysomelidae) lead the list of families of 

 injurious beetles, mth a total of 7.99 per cent. During May the leaf 

 eaters seem to be more abundant, as then they make^ up a total of 

 nearly 11 per cent. This high percentage is not maintained through- 

 out the year, however, and by September only 4.59 per cent of the 

 food is of this description. Next in order of importance from the 

 viewpoint of quantity consumed come the leaf chafers and dung 

 beetles (Scarabaeidae) . The true dung beetles should be considered 



Fig. 3. — Yearly summary of the various items in the food of the Philadelphia vireo (Vheosylva philadel' 

 phica), based on the analysis of the contents of 75 stomachs 



mildly beneficial, inasmuch as they carry beneath the surface 

 quantities of fertilizing elements. As the very nature and mode 

 of life of the vireo, however, prevents it from catching many of these, 

 they have been included with their injurious cousins, the leaf chafers. 

 Taken together, they represent a total of 6.94 per cent, all eaten 

 before September. In June the percentage is very high (14.08), 

 and it is almost all leaf chafers. 



A third group of injurious beetles found with some frequency in 

 the stomachs is the suborder lUiynchophoia, or weevils, which make 

 up 3.43 per cent of the food of the rhiladclphia vireo. Although 

 this proportion is not very great, it appears to be evenly distributed 

 throughout the year. The wood-boring beetles, Jkiprcstidac and 

 Cerambycidao, and the plant-feeding Elatcridae together make up a 

 little less than 1 per cent of the total. Mxcept in June, when these 

 forms exceed 2 per rent, the itcin is insignificant. TIk; rest of tlio 

 beetles eaten, including benelicial, injurious, and neutral forms in 



