370 Report oF THE ENTOMOLOGISTS OF THE 
covered with long gray hairs. When first hatched they swarm 
upon the egg mass. If other food is not plenty they will eat the 
glue that covers the eggs. About 100 caterpillars hatched in a 
cage in the laboratory subsisted for 6 days upon no other food 
than the frothy glue that protected the eggs from which they 
hatched. 
The caterpillars spread a thread of silk wherever they go. The 
young when disturbed will drop suddenly, suspending themselves 
by means of a silken thread in much the same manner as the 
canker worm. ‘This habit of the young is not common with the 
mature caterpillars. . ag | 
Soon after hatching, if food is plenty, they select. a place to 
build a nest. Usually the nest is built by only one colony of cater- 
pillars, but if two masses of eggs are placed near together the 
caterpillars from both masses may unite in building a single nest. 
From observations on several nests it appears that if the weather 
is favorable and food plenty the caterpillars are ready to begin 
building the nest within about two days after hatching. The 
place selected is usually the angle formed by some branching limb 
near the egg mass. _ The larve are social, living together within 
the nest-and feeding together upon the leaves. 
The number of molts.— Some of the caterpillars kept in breed- 
ing cages molted 5 and a few 6 times. The first 2 molts 
take place within 7 or 8 days after hatching and the third 
about a week from the second. The fourth and fifth take place 
within the next 2 or 8 weeks and the sixth, when it occurs, 
4 or 5 days later. The color markings begin to show prominently 
after the first molt. 3 
Growth and feeding habits—— Most of the caterpillars under 
observations were fully grown and ready to pupate about 6 weeks 
after hatching. They were extremely voracious especially when 
about two-thirds grown. It has been estimated that when at this 
age a single caterpillar will eat two fair-sized apple leaves in a 
single day. A nest of 200 caterpillars all eating at this 
