INSECT FOOD OF THE BLUE GROSBEAK. 83 
Injurious beetles comprise 24.4 percent of the grosbeak’s food, 
almost half (11.25 percent) of which amount consists of members of 
the May beetle family (Scarabeide). Adult June bugs, and their 
larvee, the white grubs, were devoured by some birds to the exclusion 
of other food, and 1 grosbeak had eaten 3 of the common dung- 
beetles (Aphodius fimetarius). Weevils are next in importance 
among beetles, and 7.18 percent of the bird’s seasonal food was made 
up of these pests. Many of them were scarred snout-beetles (Otio- 
rhynchide) and curculios (Curculionide) ; some of them certainly 
were injurious species. Two grosbeaks selected the conspicuously 
red and black colored hillbug (Rhodobenus 13-punctatus), each 
eating 2. Leaf-beetles (Chrysomelidz), wood-borers (Buprestide), 
click-beetles (Elateride), and long-horned beetles (Cerambycide), 
nearly all of which are injurious, were also devoured. 
The most important element of the animal food, however, is grass- 
hoppers. Crickets and long and short horned grasshoppers are 
eagerly consumed, composing 27.2 percent of the total food. Thirty- 
two of the 51 
blue —_ grosbeaks 
ate them, several 
taking nothing 
else. They are fed 
to the nestlings 
in generous meas- 
ure, and without 
doubt are the 
most important single article of diet. During one of the historic out- 
breaks of the Rocky Mountain locust, the blue grosbeak was found to 
feed on other grasshoppers among the swarming hordes, and it is cer- 
tain that the pest itself was not overlooked. A very closely-related 
species, called in contradistinction the lesser migratory locust (Jfe- 
lanoplus atlanis, fig. 39), has been identified from the stomachs exam- 
ined. 
But little insect food in addition to that above discussed is con- 
sumed. A fly or a wasp is rarely secured, and one ant and a saw- 
fly larva’ were eaten. Besides insects, a small amount of other animal 
matter was present in the stomachs. Spiders or their egg-sacs were 
eaten by 2 birds and snails by 9. The latter may be taken in lieu 
of gravel. . 
Fic. 39.—Lesser migratory locust (Melanoplus atlanis). (From 
Lugger, Minnesota Experiment Station.) 
MINERAL MATTER. 
Only 2 adult blue grosbeaks out of a total of 38 had taken inor- 
ganic mineral matter, and the percentage of such material is only 
0.63. Of 13 nestlings, 7 contained mineral matter in quantity suffi- 
cient to make the average for the whole group 8.8 percent, which is 
