10 
ally a small amount of the bark over which the web is constructed appears 
to have been excavated. The cavity is lined with fine silk. 
THIRD-STAGE LARVA 
When first molted, the third-stage larva is about 6 mm. long. In its hiber- 
nating web it contracts to about 4 mm. in length. Head black, 0.63 mm. wide. 
Body slightly darker in color than in second stage ; being contracted, it 
appears much more hairy. Contraction of the body makes the light colors 
on dorsum more pronounced. 
Normally the third-stage larvae do not feed and do not leave their 
hibernaculum until the following spring. Occasionally they have 
been observed crawling on the trees on warm days in the late fall 
and early winter. Such larvae have not been known to reenter their 
hibernating quarters, and those observed died without attempting 
to construct new ones. In the laboratory experiments which have 
been performed, third-stage larvae have not fed or left their hiber- 
nating webs at any time during the fall or winter. 
In the latter part of April the third-stage larvae begin emerging 
from hibernation, the emergence continuing through the first three 
weeks of May, with a maximum early in the month. After five or 
six days of feeding, under laboratory conditions, the larvae inclose 
themselves in rather coarse webs, in which they molt. In the field, 
just before molting, the larvae construct for this purpose webs simi- 
lar in appearance to the hibernating w r ebs. Only the epidermis of 
the leaf is eaten by third-stage larvae. 
FOURTH-STAGE LARVA 
Newly molted larva 8 mm. long. Head black, 0.95 mm. in width. Body 
similar to that of third-stage larva, with hairs much longer. 
Fourth-stage larvae feed from five to six days, consuming much 
more food than larvae in the previous stages. They do not confine 
their feeding to the epidermis of the leaves, but eat small, irregular 
holes, avoiding the larger veins. These larvae prepare slight webs 
across the fissures of the bark, beneath which they molt. 
FIFTH-STAGE LARVA 
Newly molted larva 12 mm. long. Head black, with a slight bluish tinge, 
2 mm. in width. Body black, mottled with white markings of irregular shape, 
which form distinct subdorsal lines on each segment. On the dorsum of the 
first, and that of the last, body segment is a white irregular blotch. On each 
of the intermediate segments are two white blotches of irregular shape. These 
are placed anteriorly and posteriorly on the segments, so that the posterior 
blotch on each segment combines with the anterior blotch of the one following. 
These white blotches make the caterpillar conspicuous, and are characteristic 
of this species. Tubercles in this stage reddish brown, and hairs longer than 
in preceding stage. 
In feeding, the fifth-stage larvae consume the entire leaf with 
the exception of the larger veins. This stage occupies five to six 
days, after which the larvae prepare their molting webs in the fissures 
on the tree trunks. 
