372 
LEPIDOPTERA. 
or the camp * lackey-caterpillars of Europe, for which they 
have been mistaken. From the first to the middle of June 
they begin to leave the trees upon which they have hitherto 
lived in company, separate from each other, wander about 
awhile, and finally get into some crevice or other place of 
shelter, and make their cocoons (Plate VII. Fig. 15). 
These are of a regular long oval form, composed of a thin 
and very loosely woven web of silk, the meshes of which 
are filled with a thin paste, that on drying is changed to a 
yellow powder, like flour of sulphur in appearance. Some 
of the caterpillars, either from weakness or some other 
cause, do not leave their nests with the rest of the swarm, 
but make their cocoons there, and when the webs are opened 
these cocoons may be seen intermixed with a mass of 
blackish grains, like gunpowder, excreted by the caterpillars 
during their stay. From fourteen to seventeen days after 
the insect has made its cocoon and changed to a chrysalis, 
it bursts its chrysalis-skin, forces its way through the wet 
and softened end of its cocoon, and appears in the winged 
or miller form. Many of them, however, are unable to fin- 
ish their transformations by reason of weakness, especially 
those remaining in the webs. Most of these will be found 
to have been preyed upon by little maggots living upon the 
fat within their bodies, and finally changing to small four- 
winged ichneumon wasps, which in due time pierce a hole 
in the cocoons of their victims, and escape into the air. 
The moth (Plate VII. Fig. 14 male, Fig. 17 female) 
of our American lackey-caterpillar is of a rusty or reddish- 
brown color, more or less mingled with gray on the middle 
and base of the fore wings, which, besides, are crossed by 
arc blue, with a narrow red stripe; on the top of the eleventh ring is a little 
blackish wart; and the belly is dusky. 
* The castvensU , or camp-caterpillar, has a narrow broken white line on the 
top of the back, separating two broad red stripes, which are dotted with black; 
the sides arc blue, with two or three narrow rod stripes; the head and firstring 
are not marked with black dots; there is no wart on the top of the eleventh ring; 
and the belly is whito, marbled with black. 
