56o 



Bulletin 170. 



shroud or cocoon, composed of silken threads, in which are mixed 

 the hairs from its own body and the whole is given a powdery- 

 appearance by the caterpillar ejecting a liquid which becomes a 

 yellowish powder upon drying. A cocoon is shown in figure 103. 

 Within this cocoon the caterpillar soon changes to the curious 

 brown object — a pupa — shown at p in figure 102. In about ten 

 days or two weeks after the cocoon is spun, or during the latter 

 part of June, there emerges from it the adult insect — a buff- 

 brown colored moth marked viith a slightly darker band across 

 each front wing ; ;;^ and/ in figure 102 represent the male and 

 female moth respectively. The moths fly mostly at night and 

 are often attracted to lights. 



Soon after emerging, the female moths deposit their eggs in 

 masses of about two hundred each around the smaller twigs, as 

 shown at e in figure 102. The eggs are covered with a varnish- 

 like substance ; at^ in figure 102 is shown an old, hatched egg- 

 mass with the varnish-like coating worn off. The eggs thus 



deposited early in July will remain 

 unhatched until the following April. 

 Thus there is but one brood of the 

 caterpillars in a year. 



A very important difference in 

 habit between the forest and the 

 apple tent caterpillar should here 

 be emphasized. It is this: A colony 

 or family of forest tent caterpillars 

 hatching from the same egg-cluster, 

 like their near relatives, work and 

 live together during most of their 

 life dtit they never make any tent or 

 nest. The only approach to a web 

 made by the forest tent caterpillars 

 is a thin carpet spun on the bark 

 or sometimes over several terminal 

 leaves on which the whole family 



IOI.-C0C0071 spun 'by a Forest usually rest in a cluster (as shown 

 Tent Caterpillar in a maple in figure 104) during the day or 



when they are shedding their skins. 



J^M 



> 





1 



} 



leaf, statural size. 



