FOOD HABITS OF THE VIKEOS 27 
Other insects and spiders. —The rest of the animal food of the Bell 
vireos is composed of a few miscellaneous insects and spiders and a 
very few snails, spiders (2.71 per cent) being the most important. 
The first appearance of this group of food items was in the stomachs 
of birds taJken in June, at which time it composed 6.93 per cent of 
the food. An immediate drop to 2.52 per cent took place the next 
month, and the percentage in August was nearly the same. 
VEGETABLE FOOD 
It is not until July that the Bell vireos feed on wild fruits. At 
that time 1.57 per cent of the subsistence is of vegetable matter. 
In August the percentage decreased slightly to 1.25. The average 
percentage for the year is only 0.7. 
SUMMARY 
During the summer months the Bell vireos consume a great many 
injurious insects and very few beneficial ones. Grasshoppers, 
locusts, caterpillars, and^ moths are frequently injurious to man's 
best interests, as also are many of the hemipterans. The percentage 
of these insects in the food of birds of this species is 73.58, nearly 
three-fourths of the total. Of the remainder about half the beetles 
and hymenopterans are injurious. This will add about 11 per cent, 
leaving about 16 per cent of the food of debatable import. As the 
small quantity of vegetable matter eaten is of no economic significance 
it may be disregarded. Ladybird beetles are about the only beneficial 
forms that the birds take, and these are not consumed in very great 
numbers. 
GEAY VIREO 
Vireo vicinior 
The gray vireo is a rare bird in a restricted range, and for this 
reason is of very little economic importance. It may be seen in 
southern California, southern Nevada, Arizona, New Mexico, as far 
east as western Texas, and south to northern Mexico and on the 
peninsula of Lower California. 
There are only two stomachs in the collection of the Biological 
Survey, and, while from such limited material it is impossible to draw 
more than an inference, it may be said that the habits indicated are 
similar to those of the Hutton and Bell vireos. Caterpillars and a 
small moth were found in one stomach, together with a stink-bug 
(Prionosoma podopioides) , a tree hopper (Platycentrus acuticornis) , 
and a tree cricket (Oecanihus) . In the other stomach two dobson 
flies (Chauliodes), a small cicada (Tibicinoides hesperius), and a 
long-horned grasshopper made up the greater part of the contents; 
two beetles (Acmaeodera neglecta and Pachybrachys) complete the 
list. 
Because of the relative infrequency of its occurrence and the 
chiefly beneficial nature of its food habits as here indicated, it is 
probable that the gray vireo will never prove destructive. 
