53 
moths which are co-generic with it all make their appearance in July 
and August. I,t is hence altogether probable that there are two gen¬ 
erations of the moth in each year; and if so, the first generation will 
make its appearance, it is quite likely, in the month of June, or at all 
events before the heads have begun to form, and when all the leaves 
are young, open, and adapted for its resort. It will consequently be 
liable, then, to do great injury to this vegetable. 
This worm in its appearance, motions and habits, has a close re¬ 
semblance to the Palmer worms which have recently stripped the foli¬ 
age from our orchards and forests so extensively, to which, as we 
shall presently see, it is related. When it is disturbed it runs briskly 
backwards, with a wriggling motion or by a fine cob-web like 
thread lets itself down from the leaf. Its castings are little black 
grains, which appear like gunpowder sprinkled thickly over the leaves 
and the ground beneath them. The pupa or chrysalis is enveloped in 
a pretty gauze-like cocoon, which may be found attached to the eaten 
leaves, two or more of them frequently in a cluster together. It is 
spun of clean white threads, crossing each other and forming an open 
net-work, through the meshes of which the enclosed chrysalis may be 
distinctly seen. The threads composing the net-work are coarsish and 
not very stout. They may be readily broken with the point of a 
needle, and the enclosed pupa be thus removed from its case for ex¬ 
amination, though the cocoon is so slightly attached to the leaf that 
it is frequently torn loose in thus breaking it open. 
Interspersed with these gauze-like cocoons upon the leaves, others 
may be met with quite different in their appearance, being opake and 
of a thick paper-like texture and a brown color. They are of an 
elliptic form, rounded at both ends, and only about the tenth of an 
inch long and a third as broad. These have been constructed by the 
larvae of parasitic Ichneumon flies, which have destroyed the worms of 
the cabbage-moth. And from the information I possess it appears that 
this parasite deposits but a single egg in each worm, from which a 
maggot hatches, which feeds internally upon the worm, yet without 
attacking any vital part whereby the worm would be prematurely de¬ 
stroyed. Thus the parasite, as in other cases of this kind, attains its 
growth at the same time that the worm reaches maturity, when the 
maggot finishes its work by destroying the little that remains of its 
foster parent, and immediately incloses itself in this paper-like cocoon. 
Of three mature worms which I enclosed in a small box over night, 
only two were found next morning. All vestiges of the third had 
disappeared, and in place of it was one of these paper-like cocoons. 
But as the worm of the cabbage-moth is such a choleric mercurial 
little fellow that when he is molested, be it ever so slightly, he darts 
backwards and wriggles about so suddenly and spitefully, it will be 
an interesting topic for some future observer to notice by what artifice 
his mortal foe induces him to remain quiet or is able to cling to him 
long enough to puncture and drop an egg within his skin. 
- The knowledge and skill which these Ichneumon and other parasitic 
Hymenopters often show in their proceedings is truly wonderful. 
Every person will recollect the larva of the Isabella tiger-moth (Arctia 
Isabella )—the large caterpillar with stiff even shorn hairs of a tan- 
color and black at each end of his body, which crawls about our yards 
and even enters our dwellings—and will probably have observed the 
fact that if when crawling he is rudely touched, he suddenly stops 
