CANKER WORMS. 



W. M. MUNSON. 



Every year come complaints of the defoliation ot orchard 

 and shade trees in May and early June. This trouble is usual- 

 ly caused by small slender inch-worms or measuring worms 

 which from their effect upon the foliage are commonly called 

 "canker worms." These larvae appear in immense numbers 

 just as the leaves put forth in the spring. They are so small 

 in the beginning, however, that they are often overlooked and 

 the cause of the backward appearance of the trees is not 

 recognized. When they first appear, and while not more than 

 one-eighth to one-fourth of an inch long, the larvae gnaw small 

 holes in the young leaves. As they increase in size the entire 

 leaf, except some of the larger veins, is destroyed and the trees 

 if badly attacked look as if swept by fire. 



Two distinct species of insects are concerned in this de 

 structive work, viz., the fall canker-worm and the spring 

 canker-worm. The habits of the two insects are much alike 

 and to the casual observer there are no distinguishing marks. 

 The striping of the larvae is slightly different, however, and 

 the spring canker-worm has three pairs of legs under the rear 

 portion of its body while the other has but two. Both species 

 are natives of this country and are about equally destructive 

 where they occur. The spring canker-worm is, however, the 

 more widely distributed, ranging from Maine to Iowa and 

 southward to Texas. 



THE SPRING CANKER-WORM (Paleacvita veruata.) 



The male moths of this species have rather large, thin, silky 

 wings, about one inch across when spread. The general color 

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



