MAINE AGRICULTURAL EXPERIMENT STATION. 23 



is bluish gray. A well defined row or band of light markings 

 near the outer margin of the front wings, and three darker, 

 irregular bands, across the same wings, together with the 

 slightly lighter color and absence of markings on the hind 

 wings, are characteristic features. The inconspicuous female 

 moths are wingless and, because of this fact, the spread of the 

 species is very slow, occurring mainly by the transportation of 

 nursery stock infested with eggs. 



The moths usually emerge from the ground early in the 

 spring — about April, or farther south in March — and the 

 females climb up the trunks of trees to deposit eggs. The eggs, 

 which are shaped something like hens' eggs and are about the 

 size of fly specks, are deposited in irregular masses, usually 

 partially concealed by loose pieces of bark. They hatch about 

 the time the leaves unfold ; the time varying with the locality 

 and the season. The larvae are "measuring worms" with 2 

 pairs of legs at the hind end of body (fig. 5). The young larvae 



Fig. 5. a, larva, showing the two pairs of pos- 

 terior legs; b, single egg, much enlarged. (Af- 



ter Riley) 



are voracious feeders and they grow rapidly, usually attaining 

 full size in from three to four weeks from the time of hatching. 

 Upon reaching full size they drop to the ground, burrowing 

 beneath the surface to a depth of two to five inches. Here each 

 one forms a cell, lined with silk which it spins, and soon trans- 

 forms to the chrysalis stage, where it remains until the following 

 spring, when the adult moth emerges as before. 



II. FALL CANKER-WORM. 



(Alsophila pometaria.) 



The fall canker-worm so closely resembles the other species 

 as to be frequently mistaken for it. For all practical purposes 

 they may be considered together, but the fall canker-worm is 

 more distinctively a northern insect. As in the other species, 

 the female moth is wingless, but in this species she lacks the 

 hairiness which characterizes the other. The male moth has 

 two light bands across the front wings instead of the single one 



