34 WOOLY BEARS. 
by connecting it with the adjoining leaves and twigs; thus 
as they gradually work downwards their web becomes 
bulky, and as it is filled with brown and skeletonized leaves 
and other discolored matter, as well as with their own old 
skins, it becomes quite an unpleasant feature in our public 
thoroughfares, parks and orchards. The caterpillars always 
feed protected by these webs; but as soon as they approach 
maturity, which requires about a month, they commence to 
scatter, searching for suitable places in which to spin their 
cocoons. If very numerous upon the same tree the food 
supply gives out, and they are forced by hunger to leave 
their sheltering homes before the usual time. When the 
young caterpillars are forced to leave their webs they do 
not drop suddenly to the ground, but suspend themselves 
g. 82.—Hyphantria cunea Drury; a, b, c, differently marked caterpillars; 
d,e, pupz; f, moth. From Div. of Entomology, Dep. of Agriculture. 
Fi 
by a fine silken thread, by means of which they easily re- 
cover the tree. Grown caterpillars, which measure 1.11 
inches in length, do not spin such a thread. Both old and 
young ones drop themselves to the ground without spin- 
ning when disturbed or sorely pressed by hunger. Favorite 
recesses selected for pupation are the crevices in bark and 
similar shelters above ground; in some cases even the empty 
