INSECTS. 



133 



NOTE. In France and Italy four days are required to form the 

 cocoon, while in England and certain parts of India forty-six days are 

 necessary for its completion ; 360 of these cocoons weigh i-J pound. 

 In the United States the Telia polyphemus is valued for its silk. Little 

 windows have been cut in their cocoons and mica inserted, so that the 

 growth of the chrysalis might be observed. 



VALUE. The silk goods produced yearly in the United States alone 

 are valued at $27,000,000. 



FIG. 168. Death's-head moth. 



Hawk-Moths (Sphingida). The hawk-moths are 

 large, swift-flying insects, with stout, spindle-shaped bodies, 

 the tongue remarkable for its length. The curious death's- 

 head moth (Fig. 168) belongs to this family. 



VALUE. The moths fertilize flowers, carrying pollen from ^>ne to 

 another, often attached to their eyes (Fig. 164). 



