IXSECTS. 





$338,000 for silk-worm eggs raised in the United States. Cocoons are also 

 sent to southern Europe for reeling, and bring from fifty cents, fresh, to 

 two dollars and a quarter, killed, a pound. North Carolina and Kai 

 are the great silk-raising states, the silk produced in the former equalling 

 the best of the French. 



Another silk-worm, the Ailanthus silk-worm, represented in the cut, lias 

 recently been introduced along with its food plant. Owing to the a 

 facility with which it is raised, its greater immunity from dis and it- 



greater power of standing cold, considerable expectations have been bi 

 upon it ; but, although it can be reared in the open air, it lias nol the 

 slightest chance of rivalling the long-familiar form. The general <"l"i 

 the moth is a rusty green, on which are spots and bands of white and pale 

 lilac. The larva is a light bluish green. 



AVe have in the United States several species which spin silk of value, 

 one of which, the Cecropia moth, is represented in the upper centre of our 

 plate. This is one of the largest moths, and is common in almost v. 

 collection. Its rich brown colors and the brightly colored eyes and bands 

 make it very beautiful. Its larva feeds on a large number of plants, and 

 were there some way of reeling the silk easily, the species might be of some 

 economic importance. 



More valuable of our native 

 forms as a silk-producer is the 

 Polyphemus moth, a form which 

 rivals the last in size and beauty. 

 Mr. Trouvelot has experimented 

 with this species as a silk-producer. 

 As it is a native of our northern 

 states, it stands our climate well, and passes 

 through our cold winters without injury, and 

 the silk is strong and glossy, thus making it 

 of value as a commercial product. Mr. Trou- 

 velot began his experiments in 1860, and, as 

 he had to learn everything, he at first met 

 with ill success, but in 1865 he had become 

 expert in cultivating them, and c; in that year 

 not less than a million could be seen feeding 

 in the open air upon bushes covered with a 

 net; five acres of woodland were swarming 

 with caterpillar life." 



The growth of the larva is astonishingly rapid. On hatching it we 

 but a twentieth of a o T ain ; in fifty-six days it increases its 



Fig. 270. 



American nlk-worn 



- 



