THE TENT CATERPILLAR 



51 



Two or three weeks later another change takes place, and 

 from each cocoon there comes forth a reddish-brown moth 

 (Fig- 7)- The male moths are considerablj- smaller than the 



females. These moths are 

 nocturnal, flying only at night, 

 and are to be found throughout 

 the greater part of July. The 

 JT -— ' ^p "— i^ females deposit the eggs upon 



FIG. 7:-Female Moth (After Riley) ^^^ ^^'^^ "'' ^'^^^ ^"'l «°«n 



die. As already stated, these 



eggs remain unhatched until the following spring. 



THE EXTENDING RANGE OF FOOD PLANTS 



The ordinary food-plants of the tent caterpillar are the apple 

 and the various kinds of wild cherry. The moths apparently 

 choose these in preference to all other trees for the reception of 

 the egg-masses. But during the outbreaks of the insect in New 

 England the last few years, as in fact in previous outbreaks in 

 other regions, many of the caterpillars have been forced by 

 hunger to attack the foliage of other trees and shrubs. In manv 

 localities the leaves of the apple and cherry trees upon which 

 the insects fed when first hatched, have been wholly devoured 

 before the caterpillars were half grown. Of course this must be 

 the result when more egg-masses are laid upon a tree or shrub 

 than can be matured upon its leaves. Thus threatened by star- 

 vation the caterpillars have been forced to leave their nests, 

 descend to the ground, and crawl about in search of food. Many 

 of them ascend the nearest trees and shrubs, and nibble at their 

 leaves. If these- leaves are not too distasteful the caterpillars 

 are likely to remain and complete their growth upon the new 

 food-plant thus found. If the insects are unable to live upon 

 the leaves they are likely again to crawl away in quest of some- 

 thing better. Doubtless thousands of them perish outright in 

 this search forfood, while myriads of others prematurely change 

 to pupae, and either die before maturing into moths, or develop 

 into feeble adults. 



But it is very probable that many of these caterpillars which 

 are able to complete their larval growth upon new food plants 



