72 



REMEDIES FOR THE CANKER-WORM 



tudinal lines. On the under side of the body are ten legs, six 

 just back of the head, and four near the hind end. In moving 

 about, the middle of the body is humped up, and in conse- 

 quence these insects are commonly called looping caterpillars or 

 measuring worms. When the branch upon which the insects 

 are feeding or resting is jarred, the canker-worms drop toward 

 the ground, each spinning from its mouth a silken thread, up 

 which it can crawl again when danger passes. 



Late in spring or early in summer the full-grown canker- 

 worms descend to the ground, where, at or slightly beneath the 

 soil surface, they make slight silken cocoons. Within these 

 they change to chrysalids or pupa, remaining in this condi- 

 tion until the autumn or spring following. Then they emerge 



as small, grayish moths. 



There is a remarkable dif- 

 ference in the appearance 

 of the sexes of these moths. 

 The males (Fig. e) have 

 small bodies and broad, well 

 developed wings ; the fe- 

 males {d) have large bodies 

 but no wings. While the 

 former can fly freely the lat- 

 ter can only crawl up the 

 neighboring trees to deposit 

 their eggs ; they die soon 

 afterwards. The eggs hatch 

 when the leaves begin to ex- 

 pand in spring and the young 

 worms begin their ruinous 

 work. 



(h 



Fig. 3. — The spring canker-worm : 

 a, egg mass, natural size; b, egg, 

 magnified ; c, larva ; d, female 

 moth; e, male moth. (After 

 Riley.) 



Those who have studied the canker-worms most carefully 

 have found that there are two common species — the Fall 

 Canker-worm {Anisoptcryx po??ietarla) and the Spring 

 Canker-worm {^Paleacrita vernata). The moths of the 

 former species appear and lay their eggs mostly in autumn, 

 while those of the latter (Fig. 3) appear in spring. Both 

 species are found in New Hampshire, the spring species being 

 apparently the more destructive at the present time. 



