ATTACKING THE LEAVES. 



223 



fawn-colored silky down ; they hatch during May or early 

 in June. 



The young larvae are of a brown color ; they are very 

 active, and begin at once to make for themselves coverings of 

 silk, to which they fasten bits of the leaves of the tree on 

 which they are feeding, forming small cones, as shown at g 

 in the figure. As the larvae grow, they increase the size of 

 their enclosures or bags from the bottom, until they become 

 so large and heavy that they hang instead of remaining 



Fig. 226. 



upright, as at first. By the end of July the caterpillars 

 become full grown, when they appear as shown at /, Fig. 

 226, where the larva is seen with its head and a portion of 

 its anterior segments protruded from the bag. When taken 

 out of the enclosure at this stage, it presents the appearance 

 shown at a in the figure, that portion of the body which has 

 been covered by the bag being soft, and of a dull-brownish 

 color, inclining to red at the sides, while the three anterior 

 segments, which are exposed when the insect is feeding or 

 travelling, arc horny and mottled with black and white. 

 The small, fleshy prolegs on the middle and hinder segments 

 are fringed with numerous hooks, by which the larva is 



