APPLE AND WALNUT LEAF CRtJMPLERS. 



119 



Ezplanatio7i. — a, the larya in it* case suspended between two leaves; the dotted lines «how 

 the position of the case behind the leaf; b, the case seen separately; c, the wings of Phycila 

 nebula ; d, wings of Phycita juglandis ; e, wings of a variety of F. nebulo bred on the crab-apple. 



Phydta Juglandis, N. Sp. 



The insect to which I have given the specific name of juglandis, 

 lives in its larva state upon the hickory and black-walnut. The prin- 

 cipal interest that attaches to it lies in its close relationship to the 

 species just described, involvinoj the curious question of identity of 

 species, under diversity, not only ©f the coloration of the imago, but 

 also of the food-plant and habits of the larva. 



The moth is a much plainer insect than the apple-tree species ; for 

 whilst the latter, though tinted with subdued colors, is rather prettily 

 variegated, the walnut species is a plain cinereous or ash-gray moth, 

 with its markings so obscure and obsolete that, in most individuals, 

 they can scarcely be detected. I have before me at the present mo- 

 ment five specimens of the Phycita nebulo, and fifteen of the jP. jug- 

 landis, twelve of which I bred from larvse taken from the black-walnut, 

 and three are from the Walsh cabinet, marked as having been obtained 

 from the hickory. These last have their markings rather more distinct 

 than those from the black-walnut, but much less so than those of the 

 genuine nebulo. If we compare the P. nebulo with the average speci- 

 mens of the P. juglandis, their specific identity could scarcely be sus- 

 , pected. But if we take the best developed specimens of the latter, and 

 select the most characteristic marks of each of them, we can make up 

 an imaginary individual which would present a considerable similarity 

 of pattern to that of the genuine P. nebulo. 



But it is in the habits of the larvse, and the form and mode of at- 

 tachment ©f its case, that the most striking differences are observed. 



