57 



figure 44 a. and b.^ with figure 42 i5. shows at once. They are laid 

 in larger and more conspicuous clusters, and are not often con- 

 cealed, as are those of the common canker worm. The larvae are 

 less readily distinguished, although they can generally be separat- 

 ed. As seen in figure 44, c. d. /"., as compared with figure 42, c. 

 d. a., the markings along the back arc less numerous. The head 

 is darker in the fall canker worm, and the lai-v^ae when first hatched 

 are lighter green. They feed alike on the leaves of the food plants 

 as they unfold in the spring. The first described species in all 

 cases, I believe, does greater damage than the other, as it is most 

 abundant. 



As shown in figure 45, b.^ the female is wingless, the body is 

 smoother and rather more slender than in a., vernata, and has not 

 the dark median band. The general color is a dark gray. Figure 

 45 shows the magnified surface of the back, and this may be com- 

 pared with figure 45, c/., to show the difference in the two species. 



Figure 45. 



Anisopteryx pometaria, Harr. 



Fall Canker Worm. 

 Adult forms, a. male, b. female. 



The male, figure 45, «., of the fall canker worm, is darker than 

 that of the other species, though closely resembling it. Other 

 differences, as well as many resemblances, will be noticed on com- 

 paring the figures of one species with those of the other. So far 

 as preventive measures go, I wisli to notice that although so simi- 

 lar, the two species require dissimilar treatment. Says Dr. Riley 

 in this connection : "In brief, all the more important measures to 

 be pursued in our warfare against the spring canker worm, such 

 as hindrances to the ascending of the moths in the spring, the re- 

 moval of loose bark, and keeping the trunk and limbs as smooth 

 and clean as possible, the employment of hogs and fall plowing 

 are in the main useless as directed against the fall canker worm, 

 which must be fought principally by traps or barriers applied to 



