6 
through the cracking skin, leaving the chrysalis hanging from the bag, 
as shown atc, figure 5. Thechrysalis of the female does not push its 
vay at all out of the bag, but the skin cracks and the female gradually 
works her way partly out, her head reaching the lower end of the bag, 
(fig. 5, d@). The males fly about, seeking the bags of the females, and 
when one is found in which the head of the female is near the end, 
showing that she has emerged from her chrysalis skin, the male pushes 
his enormously protrusive and, in fact, telescopic genital apparatus up 
into the bag to the anal end of the female and fertilizes her. The 
female then works her way back into the chrysalis skin, gradually filling 
it with eggs until more than half of it is filled, scattering in among the 
eggs some of the sparse hairs from her body. Having done this she 
forces her shriveled 
body out of the open- 
ing, falls to the ground, 
and dies. The eggs re- 
main in this way until 
the following spring, 
when they hatch, as 
previously described. 
There is thus only one 
generation annually. 
Nore.—There is a possi- 
bility that the bags of this 
extremely common insect 
might be made commer- 
cially useful. Itssilk, from 
a practical standpoint, has 
always been ignored, but it 
is firmer and stronger and 
more easily spun as carded 
Fic. 5.—Bagworm at (a, b, c) successive stages ot. growth. c, Male gilk than that of most other 
bag; d, female bag. Natural size (from Howard). 
native silk cocoons. 
NATURAL ENEMIES. 
Although apparently well protected from the attacks of birds by 
its tough case, the bagworm is somewhat extensively parasitized by 
several forms of ichneumon and chalcis flies, most of them species 
which affect also similar tree-feeding caterpillars. Prominent among 
these is the common /%mpla inquisitor Say (fig, 6), which, however, 
more commonly parasitizes the tussock moth and tent caterpillars.@ 
The related P. conquisitor Say is also a parasite of the bagworm and 
a third species of ichneumon, A//ocota ( Hemiteles) thyridopterigis Riley 
(fig. 7), is usually the most abundant of all. Four or five individuals 
of this species commonly infest a single bagworm, spinning for them- 
selves white silken cocoons within the bag. 
«@ Malacosoma spp. 
[Cir. 97] 
