28 BUTTERFLIES OF MAINE. 
tween them. They measure about one twenty-fifth of an 
inch in length, and about one-fourth as much in diameter. 
The eggs hatch in about a week, and the young larva, which 
is then very pale yellow, first eats the shell 
from which it has escaped, and next it spins a 
carpet of silk upon which it remains, except 
when feeding. At some point outside of the 
mat upon which it rests, it eats a round hole 
through the leaf, and very soon changes its 
color to a pale green, or near to that of the 
leaf upon which it feeds. Dr. Fitch states 
that it sheds its skin three times before it 
S% reaches maturity. At this time they are about 
Fig. 7. Pieris rape. an inch long or a trifle more. (Fig. 7, a), of a 
@ larva. pup® Hale grass green color, with a pale yellow line 
along the back, and a row of small yellow spots along the 
side. 
Having reached its full growth, the larva wanders off to 
some sheltered place, as under a board, fence-rail, or even 
under the edge of a clapboard on the side of a building, where 
it spins a button of silk in which to secure its anal legs, then 
the loop of silk to support the forward part of the body, after 
which the skin is molted and the pupa appears. 
The pupa (Fig. 7, 6), is about three-fourths of an inch 
long, quite rough and uneven, with projecting ridges and 
angular points on the back, and the head is prolonged into a 
tapering horn. In color they are very variable; some are 
pale green, others flesh colored or pale ashy gray and sprinkled 
with numerous black dots. There are two broods a year in 
Maine; the first butterflies are on the wing during the early 
part of June, and the next brood in September. The winter 
is passed in the pupa state. 
A minute insect ( Pteromalus puparum, L.) frequently 
attacks the pupa, boring through the outside and depositing 
its eggs within. These hatch before the time for the butter- 
fly to emerge, and feeding on the contents, destroy the life 
of the pupa. Ihave bred over forty of these minute parasites 
from a single pupa. 
