42 



FOURTH ANNUAL REPORT OF 



Variety nebulella (Fig. 30, e) . — I have bi'ed a single specimen from wild Crab (Cralagus) 

 which differs in some essential features from the normal form, but which nevertheless can only be 

 considered a variety of it, as I observed no larval differences. It differs in the more uniform iiud 

 subued tone of the front wings, the markings being more suffused and indistinct; but principally in 

 the relative narrowness of the space outside the transverse posterior liue the greater consequent 

 width of the middle area, and smalluess of the triangular brown spot — the space it occupies on the 

 inner margin being scarcely one-half as wide as that between it and the ti-ansverse posterior line. 

 The discal spots are also separated. 



Described from one good specimen. An interesting fiict connected with this variety is, that pre- 

 cisely the same form occurs in Europe, as I found a single specimen in the cabinet of M. J. 

 Lichtenstein of Moutpellier, France, which he had captured in that vicinity, and which he allowed 

 me to bring home for comparison . It seems to be rare , even there , and whether indigenous or impoited 

 from this country, is a question yet to be solved. 



THE WALNUT CASE-BEAEEE— ^croias^s juglandis, LeBaron. 



(Lepidoptera Phycidte . j 



[Fig. 20.] 



There are several other worms 

 tolerably common with us which 

 form cases very much like those of 

 the Rascal Leaf-crumpler just de- 

 scribed. One of these which is tor- 

 tuous and crooked, like the pre- 

 ceding, is found attached to the leaf 

 of the Post oak, the worm skeleton- 

 izing- the leaf for food. Another, 

 which is straight, is found on the 

 Soft maple, the inhabitant draAving 

 a few leaves together and likeAvise 

 skeletonizing them. The moths which these produce are not yet known ; 

 but there is a straight case-bearer found on Hickory and Walnut which pro- 

 duces a moth so much resembling our nebulo, that, though the insect cannot 

 be considered a very injurious one, I am led to give a brief account of it for 

 l)ur2D0ses of comparison, and to show how distinct species, with constant 

 larval characteristics, may so graduate into each other in the perfect state 

 as to render knowledge of their larval habits absolutely necessary to dis- 

 tinguish them. 



The case of this insect (Fig. 20, b) is invariably straight, and the excre- 

 mentitious grains which cover it on the outside, are very closely and neatly 

 woven together. It is attached by the small posterior end to the main leaf- 

 stalk, and the worm draws down and fastens two of the leaflets to hide it, 

 and then feeds upon them from the point to the base (Fig. 20, a). The 

 worm differs in no respect from that of nebulo, except in being more com- 

 monly dark greenish. There is, in all probability, but one brood a year, 

 and as with nebulo the larva passes the winter in a i^artially grown condi- 

 tion ; and as it lives during the summer on a compound leaf, it very wisely 

 abandons this leaf, and anchors its case firmly to the more enduring twig, 

 before winter sets in. 



