154 INJUKIOUS INSECTS 



and having finally decided on the spot, each one spins an 

 oblong-oval yellow cocoon (fig. 100, d], the silk composing 

 which is intermixed with a yellow fluid or paste, which 

 dries into a powder looking something like sulphur. A 

 few individuals almost always remain and spin up in the 

 tent, and these cocoons will be found intermixed with the 

 black excrement long after the old tent is deserted. 



Within this cocoon the caterpillar soon assumes the 

 chrysalis state, and from it, at the end of about three 

 weeks, the perfect insect issues as a dull yellowish-brown 

 or a reddish-brown moth (fig. 101), characterized chiefly 

 by the front wings being divided into three nearly equal 

 parts by two transverse whitish or pale-yellowish lines, 

 and by the middle space between these lines being paler 

 than in the rest of the wing in the males, though it is 

 more often of the same color, or even darker in the fe- 

 males. The species is, however, very variable. 



The moths do not feed, and the sole aim of their lives 

 seems to be the perpetuation of their kind; for as soon 

 as they have paired and each female has carefully con- 

 signed her eggs to some twig, they die, and when the 

 proper time comes around again the eggs will hatch, and 

 the same cycle of changes take place each year. 



This insect in all probability extends wherever the 

 wild Black Cherry (Prunus serotina) is found, as it pre- 

 fers this tree to all others; and this is probably the reason 

 why the young so often hatch out before the apple buds 

 burst, because, as is well known, the Cherry leaves out 

 much earlier. Besides the Cherry and Apple, both wild 

 and cultivated, the Apple-Tree Tent-caterpillar will feed 

 upon Plum, Thorn, Rose, and perhaps on most plants be- 

 longing to the Rose family, though the Peach is not con- 

 genial to it, and it never attacks the Pear, upon which 

 it is said that it will starve. It does well on Willow and 

 Poplar, and even on White Oak, according to Fitch, who 

 also found it on Witch Hazel (Hamamelis) and Beech. 



