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4. The Easpberry Plume Moth. 



{Oxyptilus delavariciis, Zeller.) 



Order Lepidoptera. Family Pterophorid.e. 



(Plate X. Fig. 2.) 



Late in May we found occasionally at Normal, feeding upon the 

 leaves of the blackberry, a very peculiar, small green larva, having 

 a general resemblance to the raspberry slug, (Selandria ruhi), but 

 belonging to the Lepidoptera. This larva, neAV to us when first 

 observed, was determined by breeding to be that of the plume moth, 

 Oxyptilus delavaricus, of the family Pterophoridfe. 



This insect has already been noticed in Saunders' Insects In- 

 jurious to Fruits (pp. 814 and 315), where figures of the larva and 

 imago are given, and all these stages are briefly described, but the 

 species is not there identified. For the determination of the speci- 

 mens bred by me I am indebted to Prof. Fernald, of Orono, Maine. 



The larva, when full grown, is about .4 of an inch long, of a pale 

 green color, sometimes slightly streaked with pale yellow; with a 

 single transverse row of six large tubercles to each segment, each 

 tubercle bearing a spreading cluster of stiff spines which are slightly 

 emarginate at their tips. The dorsal rows of tubercles are larger 

 than those upon the sides, and the spines upon the former (six or 

 eight in number) are likewise the longest of all. Scattered spines 

 also occur elsewhere on the body. 



The prolegs of this larva are of very unusual form. They arise 

 from thick wart-like bases, and extend downward a distance equal 

 to two-thirds the depth of the body, as smooth, straight, slender, 

 tapering appendages, which expand suddenly at their tips. The 

 posterior pair of these prolegs, however, thicker than the others, are 

 beset with spines. 



The tarsal joints of the articulated legs are similarly slender, 

 tapering, and elongate, and each terminates with a movable claw 

 capable of shutting back against the tip of the extremity. 



The head is yellowish, smooth, with a few long bristles in front, 

 mouth parts dusky, thoracic legs nearly black, the abdominal pro- 

 legs pale at base, but rapidly darkening and becoming black on the 

 distal half. 



The pupa is green when fresh, angular, margined on each side 

 with a whitish ridge, and with a double row of clusters of stout 

 branched spines along the back. The abdomen is slender and acute ; 

 the wing pads extend three-fourths the length of the body, the head 

 and thorax being de curved so as to give the front of the pupa an 

 obliquely truncate outline. The back of the thorax is beset with 

 rather slender simple spines ; wing pads and under surface of the 

 body smooth except for a thick transverse tuft of hairs upon the 

 middle of the under side of the abdomen, a short distance behind 

 the tip of the wing pads. 



Length 8 mm. 



