17 
statement, as all the writers who describe the habits of this or the 
congeneric species, state directly or indirectly that they hibernate in 
the pupa or chrysalis state. This has been known in Europe from the 
days of Harold, and in America, the same fact has been observed 
from the time of its discovery to the present. 
This species is generally understood to be two brooded. The per¬ 
fect insect was taken here last spring early in March; and there are 
a few worms now (Nov. 26,) on the cabbages. The butterflies have 
been more or less numerous all summer, but they appeared to be most 
abundant at three periods; the spring brood in March and .April; the 
July brood and September brood. Hence I feel quite certain that we 
had three broods in the southern extremity of the State last year. 
Natural Agencies which assist in its destruction —Fortunately for 
the gardener this and the other species of cabbage butterflies are sub¬ 
ject to the attacks of certain parasites which aid very materially in 
their destruction. 
Curtis in his “Farm Insects” describes and figures several species of 
parasites which prey upon the three species of cabbage butterflies 
found in England, and shows how thoroughly they keep in check 
these troublesome worms. These are chiefly minute ichneumon-flies 
of the Chalcid group, some of which deposit their eggs in the eggs 
of the butteiflies; another punctures the caterpillar and deposits its 
eggs in its body, while another places its eggs on the outside of the 
chrysalis so that when hatched the little grubs can work their way 
into the interior. The last of these, the Pteromalus puparum of 
Linneaus is found also to be a native of this country; and since the 
advent of the European cabbage butterfly which, we are now describ¬ 
ing ( Pieris raped), has manifested its desposition by attacking the 
chrysalis. It was not known that this Chalcid was a native of this 
country, but when observed, was supposed to be an importation which 
had been brought over from the eastern continent with its host, until 
Dr. Packard, by comparison of specimens found here and in England, 
ascertained they belonged to the same species. 
This little Hymenopterous insect, rather less than one-tenth of an 
inch long, is wasp-like in form, with four delicate transparent wings, 
very slightly reflecting the prismatic colors, the anterior pair with a 
single short, dull yellowish nerve; the head very short and broad; 
the body of the female is a blackish green, that of the male some¬ 
what pale-green. 
The following more exact description is by Dr. Packard: 
“ Description. —The male of the Pteromalus is a beautiful pale-green 
fly, with the body finely punctured and emitting metalic tints; the 
abdomen, or hind body, is flat, in dried specimens with a deep crease 
along the middle of the upper side, and it is much lighter in color 
and with more decided metallic reflections than in the rest of the 
body. The antennae are honey-yellow, with narrow black wings. The 
legs are pale honey-yellow. It is .08 to a tenth of an inch in length. 
“The body of the female, which would be thought at first to be an 
entirely different kind of an insect, is much stouter, broader, with a 
broad oval abdomen, ending in a very short ovipositor, while the 
underside of the body near the base has a large conical projection. 
It is much duller green than the male, and the body is more coarsely 
punctured. The scutellum of the metathorax is regularly convex, not 
keeled, in both sexes. The antennae are brown, and the legs brown, 
—2 
