Biology of Staphylinidae 241 
Adults fed in confinement as readily as do the larvae. 
Stenus sp. (two cultures of two each) almost immediately 
attacked maimed flies which were placed in the cultures. 
Philonthus —— killed and ate flies (Muscidae and 
Drosophila) and on May 6, 1926, near Bloomington, Indiana, 
I captured one individual with a dipteron, one of the 
AHelomyzidae in its mandibles which clearly shows that the feed- 
ing in the laboratory was natural. Philonthus sp. was found 
in large numbers feeding on fly larvae in dung at Winfield, 
Kansas. Creophilus z villosus fed readily on blow fly larvae and 
pupae which were placed in the culture. At Douglas Lake, 
Michigan, August 1, 1926, at a carrion trap set by C. H. Martin, 
he and I observed Creophilus villosus eating a ‘large fly larva. 
Dithalastes clugulatus fed on blow fly larvae and pupae, ant 
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of this laboratory, while . collecting for me at Charlestown, 
Indiana, saw an O. cingulatus capture a fly which was feeding 
hiding place and captured the fly, one of the Muscidae, before 
it was able to take wing. A second beetle was taken while it 
was chasing a fly. Both beetles and the fly are in my collection. 
Staphylinus —— killed June ec (Melolonthinae), silphid 
beetles (Silpha noveboracensis Forst.), blow fly larvae and 
pupae, ant ee and pupae, tecines and Drosophila. When 
placed in a Drosophila breeding j jar the beetles turned over and 
over in their efforts to capture all the flies which came near 
them. In the open they feed on a variety of insects. On May 
6, 1926 near Bloomington, Indiana, I found a large S. maculo i 
in a small nest-like cavity under “dun ung, and in this nest there 
were large numbers of pieces (abdominal segments, elytra, 
heads, and thoraces) of various Scarabaeidae common to dung. 
Whenever more than one adult or larval staphylinid is placed 
in a culture which is small or which does not contain sufficient 
food, cannibalism will result. Staphylinus violaceus fed readily 
on termites and Drosophila. Olophrum obtectum feed freely on 
fresh beef, several beetles surrounding the beef and feeding 
wherever a small bit was exposed. 
Staphylinus maculosus is convenient for observation because 
of its size. One of these beetles easily killed a medium sized 
moth and ate the abdominal parts. The staphylinid approached 
cautiously, cat-like, with the tip of the abdomen elevated and 
the head held close to the ground. The moth was grasped by the 
tip of its abdomen and during the ibis which ensued, the 
staphylinid, in a bull-dog like manner bit nearer and nearer to 
the thorax. At the first opportunity the oe was securely 
grasped by the thorax and soon crushed. The attack on the 
June bug was not essentially different but as no vulnerable 
