THE APPLE-TREE TENT CATERPILLAR, 5 
adjacent twigs, the resulting caterpillars may unite in one nest. 
Wherever they go each larva spins a thread of silk, the young indi- 
viduals hanging suspended from a silken thread when they drop, as 
do the cankerworms and many other larve. The nests, at first small 
and affording but little shelter, are gradually enlarged as the cater- 
pillars grow and soon furnish ample protection. Upon close exami- 
nation the nests of this species will be found to be made up of layers 
of silk, with room for the larve between the layers. According to 
Fitch these layers are the result of the caterpillars’ habit of lying on 
the outside of the nest during bright weather, the few restless indi- 
viduals crawling back and forth over the resting mass, spinning silk 
Fig. 4.—Full grown apple-tree tent caterpillar. About twice natural size. (Original.) 
as they go, soon forming a new layer. During rainy and cloudy 
weather the larve remain mostly within the nest, but when the 
weather is favorable they feed at regular intervals; according to Fitch, 
in the morning, in the afternoon, and again during the night. Upon 
becoming nearly full grown the larve wander singly away from the 
nest, feeding upon such plants as come to hand. This wandering 
habit preparatory to pupation results in the scattering of the pupe 
and greatly increases the chances of their escape from destruction 
from their numerous natural enemies. 
When full grown the caterpillars are about 2 inches long, cylin- 
drical, deep black, with a white stripe along the back, and lateral 
markings, as shown in figure 4. On each side is a row of oval pale- 
84973°—Bull. 662—15 2 
