119 



The niotlis which 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 

 botli 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 the Cecro- 

 pia, which moves very sedately as becomes a, giant. 



The caterpillars of this species, the 

 young Promethea, feed during the sum- 

 mer on leaves of wild cherrv, ash an 

 other trees. They grow to be about 

 two inches long, and are distinguished 

 from others 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. 



* 



* 



79. — Cocoon of 

 Promethea 

 moth fastened 

 to a twig icith 

 silk. 



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 

 winged 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 stage and the e^g stage 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- 

 appear in numbers sufficient to make them of economic 



importance. 



511 



80. — Cocoon 

 of Pr 0- 

 inethea, cut 

 open length- 

 wise to show 

 the valve 

 like decice 

 at upper 

 end through 

 whi c h the 

 adult moth 

 pushes its 

 way out. 



dom 



