24 BULLETIN 107, U. S. DEPARTMENT OE AGEICULTUBE. 
The animal portion of the food of the young Brewer's blackbird 
at this time of the year is of economic importance and amounts to 
nearly 94 per cent. Conspicuous are caterpillars (mostly cutworms), 
which totaled 34.57 per cent, or over a third of the stomach contents. 
These insects, abundant in man}' fields and doubtless doing con- 
siderable injury, together with adult Lepidoptera, occurred in 59 
of the 78 stomachs, in several cases amounting to over 90 per cent 
of the food. Ground beetles (Carabida?) amounted to 11.45 per 
cent. WMle these beetles, as a family, are considered beneficial, 
being mainly predaceous, there are some which injure vegetation. 
This is especially true of the genus Amara, which made up the greater 
portion of this part of the food. Spiders were eaten freely by the 
nestlings and constituted 9.37 per cent of the food. Flies amounted 
to 7.34 per cent, while the remaining animal food was divided in 
small quantities among insects of several orders. 
The vegetable food is of little importance at this time of the year, 
both from its character and relatively small proportion (6.08 per 
cent). Over three-fourths was of rubbish, which testifies to the 
voracious temperament of the young, while weeds and a little grain 
formed the rest. 
The young Brewer's blackbirds obtained in July were fully fledged 
and were out of the nest picking up much of their own food. Of 
45 birds only 2 had failed to eat the weevil, and in the remaining 
stomachs it amounted to 25.47 per cent of the food. An average of 
11.47 adults, 0.24 pupa, and 25.53 larva?, or over 37 weevils in one 
stage or another for every bird, was the record made by these juve- 
nals. A few cases will illustrate the inrportance of these birds as 
weevil destroyers. One had eaten 229 larvse, 7 pupa?, and 20 adults ; 
another made away with 140 larva? and 6 adults, and the record of 
a third was 4 adults and 150 larva?. The abundance of adult weevils 
of the year's brood in the middle of July is indicated by the stomach 
of a young blackbird, which contained 95 insects in this stage. 
Another had captured 10 adults, 1 pupa, and 126 larva?. Other 
interesting records are as follows: 94 adults; 1 adult and 60 larva?; 
26 adults and 45 larva?; 21 adults and 35 larva?; 3 pupa? and 63 
larva? ; 3 adults and 50 larva? ; and 5 adults and 52 larva 3 . 
The weevil composed about one-third of the animal food during 
this period, which in turn amounted to 77.8 per cent of the total con- 
tents. Of other animal food Lepidoptera, mostly caterpillars, formed 
13.18 per cent, a little less than two-fifths of the amount taken in 
June. Hymenoptera, many of which were parasitic, made up 11.29 
per cent. Hemiptera, the bulk of which was composed of the small 
cicada, Platypedia putnami, formed 10.11 per cent. Ground beetles 
totaled 8.67, while the remaining portion was divided in small quan- 
tities under several heads. 
