BIRDS IN RELATION" TO THE ALFALFA WEEVIL. 29 
tents. Among the weed seeds were those of filaree (E'r odium cicu- 
tarium), sunflower (Helianthus sp.), pigweed (Amaranthus retro- 
flexus and A. olitoides), cockle (Vaccaria vaccaria), smartweed 
(Polygonum spp.), panic grass (Pardcum sp.), and brome grass 
(Bromus sp.). 
Four vesper sparrows were collected in May, three of which had 
eaten the weevil, the fourth having been secured in a wooded ravine 
some distance from the nearest field. The weevil formed nearly 40 
per cent of the stomach contents of the four, with an average of 
about three adults and six larvae per bird. In the remaining food, 
caterpillars (8.25 per cent), grain (11 per cent), and weed seeds (42 
per cent) predominate. 
Examination of a series of 19 stomachs in June shows that these 
fringilline birds are decidedly insectivorous during the breeding 
season. Every one had fed on the weevil, and in 4 it amounted 
to over 95 per cent of the food, while the average for the month was 
nearly 60 per cent. As many birds were collected at a time when 
the larvae were most abundant, this form of the insect appeared in 
large numbers in some stomachs. An average of 3.8 adults and over 
24 larvae per bird was recorded. One bird had eaten 2 adults and 60 
larvae, another 6 adults and 55 larvae, and a third 1 adult and 50 
larvae. The weevil contents of several others are as follows: 5 or 
6 adults and about 45 larvae ; 2 adults and 45 larvae ; 1 adult and 40 
larvae; 7 adults and 28 larvae; and 10 adults and 21 larvae. 
Of the other animal food items Hemiptera, composed chiefly of the 
small cicada, Platypodia putnami, so abundant in the oak chaparral 
of the foothills at this time of the year, formed the next largest 
portion (7.79 per cent). Clover root curculios (Sitones), "bill 
bugs" (Sphenophorus) , caterpillars, parasitic Hymenoptera, and 
grasshoppers follow in the order named. The vegetable portion 
(10.63 per cent) is divided between grain and the weed seeds pre- 
viously mentioned. 
For the month of July a larger series of stomachs (44) affords 
added evidence of the remarkable work of these sparrows as de- 
stroyers of the weevil. Only one had failed to feed on the insect. 
There was an increase in the average number of adults taken (5.36) 
and a decrease in the number of larvae (18.43) as compared with the 
preceding month, because of the presence of more adults of the year's 
brood during July. Animal food comprised 73.02 per cent of the 
contents, 52.09 per cent being weevils. One bird had eaten 65 larvae 
and 2 adults and was carrying 17 larvae of the weevil in her bill for 
her young. Another had taken 46 larvae and 22 adults. The stomach 
of a full-fledged sparrow collected in July, and still being fed by its 
parents, contained 45 larvae and 8 adults. Eighteen other birds had 
