THE FALL WEB-WORM. 



39 



••When the young caterpillars are forced to leave their webs they 

 do not drop -suddenly to the ground, but suspend themselves by a 



fine silken thread, by means of which they easily recover the I 

 Grown caterpillars, which measure 1.11 inches in length, do not 

 spin such a thread. Both old and young ones drop themselves 

 the ground without spinning when disturbed or sorely pressed by 

 hunger. 



Pupa and Cocoon. — ''Favorite recesses selected for pupation are the 

 crevices in bark and similar shelters above ground ; in some cases even 

 the empty cocoons of other moths.* The angles of tree-boxes, the rub- 

 bish collected around the base of trees and other like shelter are em- 

 ployed for this purpose, while the second brood prefer to bury them- 

 selves just under the surface of the ground, provided that the earth be 

 soft enough for that purpose. The cocoon itself is thin and almost 

 transparent, and is composed of a slight web of silk intermixed with a 

 few hairs, or mixed with sand if made in the soil. 



" The pupa (Fig. 18, d and e) is of a very dark-brown color, smooth 

 and polished, and faintly punctate; it is characterized by a swelling or 

 bulging about the middle. It is 0.G0 inch long and 0.23 inch broad in 

 the middle of its body, or where it bulges a little all round. 



The Moth (Fig. 18, 6). — " The moths vary greatly, both in size aud 

 coloration. They have, in consequence of such variation, received 



Fig. 19.—Hyphantria cunea: a-j, wings of a series of moths, showing the variations from the pure 

 :hite form to one profusely dotted with black and brown. 



many names, such as cunea Drury, textor Hear., punctata Fitch, puncta- 



tisshna Smith (Fig. 10). But there is no doubt, as proven from frequent 

 breeding of specimens, that all these names apply to the very same 

 insect, or at most to slight varieties, and that Drury's name vunot. hav- 

 ing priority, must be used for the species. 



"The most frequent form observed in the vicinity of Washington is 

 white, with a very Blight fulvous shade; it has immaculate wings. 



* We have known the substantial ooooon of Centra Co be used tor Ehls purpose. 



