Biology of Staphylinidae 251 
four eggs before 9.13.26. Quwuedius capucinus, undoubtedly, 
Oviposits during most of the warmer months or we would not 
be able to find the larvae so prevalent at all seasons. Also there 
is no apparent decrease in the number of larvae from mid- 
summer to late fall for many other species. Tachinus fimbriatus 
Oviposited in cultures in late fall. 
Pupation 
he change from larva to pupa apparently is very rapid. 
I have never observed the behavior but Quedius capucinus in 
my culture No. 782 was transferred to a new culture as a very 
sluggish larva. Fifteen pair later the culture was opened 
and the pupa was completely 
While the larva looses sak of the head and thorax before 
pupation, movement of the abdomen is not lost in the Staphy- 
lininae for twenty-four to thirty-six hours after pupation. By 
this time the chitin has hardened and it is doubtful if movement 
could take place. But I am not sure whether it is the breaking 
down of the larval abdominal muscles or the hardening of the 
chitin which first causes the loss of motion. In the subfamilies 
to move the abdomen. The phylogenetic significance of this 
retention of the ability to move the abdomen is not clear. 
Nest ForMING Benavior. The larvae of the Staphylinidae 
' produce a nest-like cavity during the last few days of larval life 
and pupation occurs within this cavity. The larva first looses 
muscular control of its head and thoraces which bend forward 
in such a way that the prothorax is at right angles with the 
head and the remainder of the body. During this time the larva 
turns and twists upon itself until it has crowded all the material 
near it to form the wall of a small cavity. Microscopic examina- 
tions of these so-called nests fail to show that the larva has 
added any substance to hold the nest together but rather the 
nest appears to be the acne product of the twisting and 
turning action of the larv. 
These nests serve as a oe for the larvae while they 
_ are inactive and for the pupae before the chitin dries. It would 
be more difficult for parasites and predators to reach the in- 
active larva or pupa in this nest than it would be if no nest 
was formed. The nests are not necessary to successful pupation, 
as a large number have pupated on the bare surface of the 
tin salve boxes which I use for culture containers. Some larvae 
after the nests were opened for ney ee threw themselves 
- out of the nests and pupated on the floor of the culture, and 
_ quite often the floor of the culture RE one side of the nest. 
The =o available make little or no difference as Philonthus 
