664 AN INTRODUCTION TO ENTOMOLOGY 



Subfamily BREPHIN^ 



The members of this subfamily are most easily distinguished 

 from other geometrids by the fact that their eyes are small and oval. 

 It is represented in our fauna by only five species, of which the follow- 

 ing one is the best-known. 



Brephos mfans. — This interesting species has been found only in 

 the northeastern part of our country ; its range is from Labrador to 

 New York. It is a blackish-brown moth with 

 the fore wings marked with pinkish white 

 and the hind wings with reddish orange (Fig. 

 8 1 8). The specimen figured is a male. In 

 the female the black border on the outer 

 margin of the hind wings is narrower, and 

 the subterminal, light band on the fore wings 

 is more distinctly marked. In the larva the 

 -Brephos infans. prolegs are all present; but the first three 

 pairs are stunted. The full-grown larva 

 measures 30 mm. in length. The color of the larva on the dorsum 

 varies from apple-green to blue-green according to age. The food- 

 plant is white birch. 



Subfamily CENOCHROMIN^ 



This subfamily is represented in our fauna by only three species 

 of which only the following one is well known. 



The fall canl<:er-worm, Alsophila pometdria. — The canker-worms 

 are well-laiown pests, which are often very destructive to the foliage 

 of fruit-trees and shade-trees. Although they attack many kinds of 

 trees, the apple and the elm are their favorite food-plants. 



There are two species of canker-worms which resemble each other 

 to such an extent that they were long confounded; but they differ 

 structurally, being members of different subfamilies; and they differ 

 also in habits. The two species agree in being loopers or measuring- 

 worms in the larval state, in the possession of ample wings by the 

 adult male, and in the adult female being wingless. They are easily 

 distinguished however, in all stages, the eggs, larvae, and adults 

 differing markedly. 



The fall canker-worm is so called because the greater number of 

 the moths mature in the autumn and emerge from the ground at this 

 season; but a considerable number come out of the ground in the 

 winter during warm weather, and in the spring. As the females are 

 wingless they are forced to climb up the trunl<:s of trees in order to 

 lay their eggs in a place from which the larv^ae can easily find their 

 food. The eggs appear as if cut oft" at the top, and have a central 

 puncture and a brown circle near the border of the disk. They are 

 laid side by side in regular rows and compact batches, and arc 

 generally exposed. They hatch in the spring at the time the leaves 

 appear; and the larvse mature in about three weeks. In this species 



