119 



The inotlis wliicli come from these cocoons do not always look 

 alike, but they are all brothers and sisters. The brothers are 

 almost black, while the wings of the sisters are light reddish 

 brown, with a light grey wavy line crossing the middle of \% 

 l^otli wings. The margins of the wings are clay-colored. 

 On each wing is a dark velvety spot. The adults emerge in 

 spring and are most often seen in the late afternoon. 

 Their flight is more spirited than that of tlie Cecro- 

 pia, which moves very sedately as becomes a giant. 



•3v -Jf * 



The caterpillars of this species, tlie 

 young Promethea, feed during the sum- 

 mer on leaves of wild cherrv, ash an 

 other trees. Thev ffrow to be about 

 two inches long, and are distinguished 

 from otliers by their pale bluish green 



color and yellow legs. They 



also have rows of wart-like 



elevations on their backs, some 



black and sliining, four of a 



bright red and one large and 



yellow near the hindmost end. 

 ^ ^ ^ 



The life of these giant in- 

 sects is divided into four distinct stages ; the egg, 

 deposited by the adult moth usually on or near the food 

 plant ; the larva, or caterpillar stage, when most of the 

 eating and all the growing is done ; the pupa, passed 

 inside the cocoon woven by the larva ; and the adult, a 

 wino^ed moth. 



The life cycle or generation is one year, the winter 

 being passed in the pupa stage. The insect lives but 

 a short time in the adult stao-e and the es^p- stao^e is but 

 two or three weeks. Most of the summer is devoted 

 to the caterpillar phase of its life. 



These creatures are entirely harmless. They sel- 

 dom appear in numbers sufficient to make them of economic 



importance. 



511 



79. — Cocoon of 

 Promethea 

 moth fastened 

 to a twig with 

 silk. 



80. - Cocoon 

 of Pr 0- 

 metJiea, cut 

 open length- 

 wise to shcio 

 the valve 

 like device 

 at upper 

 end through 

 whi c h the 

 adult moth 

 pushes its 

 way out. 



