364 ILLINOIS STATE HORTICULTURAL SOCIETY. 



Other legs are rust-colored, and more or less shaded with black; the 

 length of the body varies from three-quarters to an inch and a quarter; 

 the wings expand from an inch and a quarter to two inches or more. 



The female pierces through the bark into the wood in which she 

 deposits her eggs; these are oblong-oval and pointed at each end. The 

 larvae are yellowish white grubs with six true legs; they are cylindrical 

 in shape, rounded at the hind extremity, from which proceeds a horny 

 conical spine; when full grown, they are about one inch and a half in 

 length. They bore into the trunks of the elm and oak, and have also 

 been charged with attacking the apple tree in Illinois, and Mr. Wier has 

 noticed them boring in the sycamore. 



They are subject to the attacks of two ichneumon flies — Pimpla 

 atrata and Pimpla lunator. 



So far as I am aware, they have not proven injurious to any consid- 

 erable extent in the West. 



Xyleutes robinice, Peck. The Locust-tree Carpenter-moth. 



This moth belongs to section Heterocera or moths, family Cossidcs, 

 and was formerly placed in the genus Cossus, but is now placed in 

 Xyleutes, a genus established by Newman for these carpenter-moths. 

 Harris places it in the family Hepialidcz, which is nearly equivalent to 

 CossidcB. The body is densely covered with minute hairs ; the head is 

 small ; antennae of but moderate length, and furnished on the underside 

 with a double set or two rows of minute, closely-set comb-like teeth 

 {bipectinate). The male is dark brown ; the female has the abdomen dark ash 

 brown, constricted at the base, with a mass of hairs each side at this 

 point, which are white at base and dusky at the extremity ; thorax dark 

 brown, thickly covered with ash-colored, scaly down, leaving a narrow 

 dark line each side, and some naked spaces on the disk; anterior wings 

 hoary, with irregular darker reticulations, with some larger irregular dis- 

 cal spots of the same color ; hind wings dusky with black veins, covered 

 with paler hair toward the anterior margin ; tongue or proboscis wanting. 



The female is furnished with a serrated ovipositor ; she is about 1.25 

 inches long to tip of the abdomen, and expands 2 to 2.75 inches ; male 

 expands 1.50 to 1.75 inches. 



The larva of this species is a true caterpillar, possessing sixteen legs, 

 and bores into the trunks of the locust {Robinice pseiidacacia) and red oak 

 {Quercus rubra), especially full-grown and old trees of the former. They 

 perforate the tree in various directions, but mostly obliquely upwards and 

 downwards through the solid wood, enlarging their burrows as they 

 increase in size, and continuing them through the bark to the outside. 

 When fully grown they measure two inches and a half or more in length, 

 and nearly as thick as the little finger. Before transforming they line 

 their burrows with a web of silk, and returning to the interior or some 

 distance from the external opening, spin an imperfect cocoon, in which 

 they assume and pass the pupa state. The pupa is an inch and a half or 

 two inches long, of an amber color, changing to brown in front ; on the 



