WARBLERS. 45 



Bugs collectively amount to nearly 20 percent, of which a little 

 more than 4 percent are scales and plant-lice. The black olive scale 

 (Saissetia olece) and another species {Aspidiotus rapax) were found 

 in 15 stomachs. Plant-lice (Aphidida?) were contained in 39 stom- 

 achs, and from the numbers eaten appear to be favorite food. Sev- 

 eral stomachs were entirely filled with them, and the stomachs in 

 which they were found contained an avera^ of 71 percent in each. 

 The remainder of the hemipterous food, more than 15 percent, is 

 made up of stink bugs, leaf -hoppers, and tree-hoppers, with a con- 

 siderable residue of other remains not further identified. Bugs, as a 

 whole, are eaten rather irregularly, and the greater number are eaten 

 in the fall months, after which the number consumed gradually 

 decreases. Caterpillars are eaten rather regularly by the Audubon 

 warbler, but not in great numbers. They amount to nearly 14 percent 

 of the food of the season, though this figure includes a few moths and 

 chrysalids. Some cocoons of tineid moths were in several stomachs. 



Beetles of all kinds aggregate something more than 6 percent of 

 the whole diet. They belong to several families, but the snout-beetles 

 are most prominent. The others belong to about a dozen families, 

 and, except a few carrion and ladybird beetles, are injurious. A few 

 insects other than the above and some spiders, in all a little less than 

 2 percent, make up the rest of the animal food. 



Vegetable food. — The vegetable food of the Audubon warbler con- 

 sists of fruit, weed seed, and a few miscellaneous substances. As the 

 bird does not visit the fruit-growing regions during the fruit season, 

 it is not chargeable with injury to cultivated crops. Almost all the 

 fruit eaten is wild and of no value, though in the fall it probably 

 feeds to some extent upon various belated products of the orchard. 

 The total of fruit for the season is less than 5 percent, of which the 

 greater amount is eaten in the autumn and early winter, after which 

 the quantity is unimportant. 



The most prominent item of vegetable diet, however, is weed seed. 

 This is eaten to the extent of a little more than 9 percent of the whole 

 food, and is taken in almost every month of the bird's stay, the 

 greater quantity in winter. Something more than 31 percent was 

 eaten in December, 22 in January, and 31 in February, after which 

 it decreases regularly to April. One of the most important seeds 

 eaten by the Audubon warbler is that of the poison oak (Rhus diver- 

 siloba (PI. II, fig. 9). In most cases the whole seed is not eaten by 

 this bird, but only the waxy outer coating, which is easily identified by 

 certain woody granules which it contains; hence the bird does not aid 

 in the distribution of these noxious plants. The remaining vegetable 

 food, amounting to less than 2 percent, consists principally of rubbish. 



