354 



COLLEGE ZOOLOGY 



Fig. 287. — Order Lepidoptera. Army- 

 worm, Heliophila unipuncta. a, adult, b, 

 larva, with eggs of a parasitic fly (tachinid) States 

 on back, c, pupa or chrysalis. (From 

 Webster, Yearbook Dep't Agric, igo8.) 



Tropcea luna, the " tent-caterpillar," Clisiocampa americana, 

 and the silkworm moth, Bombyx mori. The silkworm moth 



(Fig. 286, C) is thoroughly 

 domesticated and, so far 

 as is known, does not occur 

 in a wild state. The silk 

 industry originated in 

 China many centuries B.C. 

 It did not become very 

 important in this country 

 until the nineteenth 

 century. There are now 

 about a hundred million 

 dollars invested in the silk 

 industries of the United 

 The moths lay 

 their eggs on cloth or 

 paper provided for them. 

 The larvae (Fig. 286, A) are fed principally on mulberry leaves, 

 and when about forty days old spin a cocoon (B) of a single 

 continuous thread averaging over a thousand feet long. In 

 the cocoon the larva pupates. 

 Silk is obtained by killing the 

 pupa with heat or boiling water, 

 then clearing away the loose out- 

 side floss, and unwinding the 

 thread. 



Among the important moths 

 of the family Noctuid^e are the 

 army-worm, Heliophila uni- 

 puncta, the cotton-worm, Aletia 



argillacea, and the boll- worm, 



. Fig. 288. — Order Lepidoptera. 



Heliothis armiger. The army- Spring canker-worm. a, male. 



worms (Fig. 287) are striped b - fe ™ ak - <= larva, d, eggs- 



' * natural size and enlarged, (rrom 



caterpillars that feed on growing circ. 9, Bur. Ent., U. S. Dep't Agric.) 



