6o 



ELEMENTARY ENTOMOLOGY 



each segment is an oval, pale blue spot with a broader, velvety black 

 spot adjoining it in front, giving somewhat the effect of an eyespot. 

 Cocoon and pupa. Having found a suitable place under loose 

 bark, in a fence, in the grass or rubbish beneath the tree, or in the 

 shelter of some neighboring building, the caterpillar settles down 

 and proceeds to encase itself in a thin cocoon of tough white 



silk. In forming the cocoon 

 the caterpillar rolls its head 

 from side to side, the silk being 

 drawn out from the lower lip 

 and hardening as soon as it 

 comes into contact with the 

 air. With wonderful contor- 

 tions it gradually shapes the 

 oval cocoon, the outer part of 

 which is composed of coarse, 

 loose white threads, with a 

 yellowish powder intermixed, 

 while the inner layer forms a 

 tougher, parchmentlike lining. 

 Frequently, when the caterpil- 

 lars are abundant and there is 

 desirable shelter near the nest, 

 several cocoons are formed en 

 masse. 



Exhausted by its labors, the 

 caterpillar now becomes quiet, 

 the body shortens to about an 

 inch long, and, finally, the skin 

 splits down the back, is sloughed off into one end of the cocoon, 

 and the transformation to a brown, oval object, the pupa, is accom- 

 plished. The pupa is about an inch long, and the surface markings 

 of the solid shell outline the legs and wings of the adult moth, but 

 otherwise there is no indication of any relationship to the larva or 

 to the adult, and, had we not seen it emerge from the larval skin, 

 it would be difficult to believe that it is the same animal. 



Moth. In about three weeks the pupal shell splits open and the 

 adult moth works its way out of one end of the cocoon. Like all moths 



FIG. 77- Web of tent caterpillars which 

 has been riddled by birds. (Reduced) 



(Photograph by Weed) 



