LEPIDOPTERA, 2/5 



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. The early stages of this species 

 are unknown ; but the larvae of European species feed upon 

 birch and poplar. With these the prolegs are all present ; 

 but the first three pairs are stunted. As this is probably the 

 ^lost primitive Geometer occurring in our fauna, we suggest 

 •he popular name Firstborn for it. In Germany an allied 

 species is known as the Jungfernkind. 



Canker-worms, — In many parts of our country Canker- 

 worms are extremely abundant. In such localities they are 

 among the more important of insect pests, often completely 

 stripping the foliage from fruit and shade trees. There are 

 two distinct species of Canker-worms; but they resemble 

 each other so closely that they were long confounded; and 

 to this day they are distinguished only by entomologists. 

 The two specit" ' >Tree in being loopers or measuring-worms 

 in the larval statev .>£i the possession of ample wings by the 

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

 differ in structural characters, as indicated below, and also to 

 a certain extent in habits. In one species the greater num- 

 ber of moths mature in the autumn and emerge from the 

 ground at this season ; in the other species the insects re- 

 main in the pupa state during the winter, emerging as moths 

 in the spring. The two species are therefore appropriately 

 designated as the Fall Canker-worm and the Spring Canker- 

 worm respectively. 



The Spring Canker-worm, Paleacrita vernata (Pal-e-ac^ri-ta 

 ver-na'ta). — The eggs are ovoid in shape, and are secreted in 

 irregular masses, usually under loose scales of bark>or be- 

 tween the leaflets of the expanding buds. The larvae hatch 

 about the time the leaves expand, and become full grown in 

 from three to four weeks. They vary greatly in color, and 

 are marked on the back with eight narrow, pale, longitudinal 

 lines which are barely discernible ; the two lateral Hnes of each 

 side are much farther apart than the others ; and there are 



