TE;NT-CA'rivl.U>ILLAR. 295 



TENT CATERPILLAR. 



Encircling the twig of apple, plum, and wild cherry trees is 

 frequently found a glistening brown mass about three-fourths 

 of an inch in length. Fig. 39. 



From such an egg cluster hatch in the spring from 200 to 300 

 caterpillars, which live in a colony and construct a whitish tent- 

 like web in the angle of two convenient branches. It is in the 

 habit of the tent caterpillars to pass their time when not feeding, 

 particularly at night and during cold or stormy weather, within 

 the tent which they enlarge as their own rapid increase in size 

 calls for more room. During the warm sunny hours of the day 

 they leave their protection and feed voraciously, defoliating the 

 branches in the vicinity of the tents. One colony is enough to 

 denude a young tree or several large branches of an old tree. 



The tent which is at first a delicate filmy silken web becomes 

 by the time the caterpillars are full grown a structure two feet 

 or more in length, unsightly with the accumulation of molted 

 skins and other rubbish. Fig. 40. 



The full grown caterpillar is nearly two inches long. It is 

 slender, dark, and velvety with numerous soft golden brown 

 hairs upon the body. A white stripe marks the middle of the 

 back, while the sides are streaked irregularly with white or 

 yellow. Along each side of the dorsal white line is a row of 

 transverse pale blue spots. 



After feeding for four or five weeks the caterpillars leave 

 the tree in search of a sheltered place for their cocoons, a 

 crevice in the bark, the eaves of buildings, or rubbish piles, 

 proving attractive for this purpose. The cocoon is an elon- 

 gated oval with the outer silk delicate and loosely woven and 

 the inner part firmer and close. The inner cell is painted on 

 the inside with a thick yellow liquid which soaks through the 

 cocoon and soon dries to a yellow powder. Fig. 41. 



The insect remains in the cocoon from two to three weeks, 

 when it emerges as a brown moth expanding about one and 

 one-half inches. The fore wings are crossed obliquely by 



