35 



received since the above was written, I learn that Mr. Webster 

 found this larva at Normal on the 29th of May. 



Some of the specimens obtained by Mr. Webster, were described 

 by Mr. Eiley under the name of Isosoma grandis in the Bulletin of 

 the Brooklyn Entomological Society for December 1884, pages 111 

 and 11*2, with the remark that they were reared from wheat stems 

 in June. 



DESCRIPTION. 



The following description is in part compiled from that of Mr. 

 Eiley and in past drawn from specimens bred and collected by us. 



Length of body from 4.2 to 4.3 mm. ; expanse 7.6 mm. ; antennse 

 slender, little clavate, but about half the length of the thorax, the 

 latter smooth except the mesonotum, which is decidedly rugulose. 

 Wings large, yellowish in color, less hyaline than those of Isosoma 

 triticl, the veins reaching the outer third, the sub-marginal four 

 times as long as the marginal. All the specimens observed were 

 winged females. Abdomen equal to or longer than the thorax, some- 

 what stouter than in Isosoma tritici, ovate-acuminate in form. The 

 head is tawny, with a narrow black shade down the middle, and 

 another beneath the eye, the posterior surface black. The scape of 

 the antennae and first joint of flagellum yellow, the remainder black. 

 The pronotum is large, and a brighter yellow than that of tritici. 

 There are two tawny spots upon the back, and the propectus is yel- 

 low in front. There is also a large tawny spot upon the pleura, 

 above the middle coxae. The abdomen is shining black throughout, 

 (except the tips of the anal appendages, which are yellow), and is 

 very sparsely covered with pale hair averaging about one-half the 

 length of the segments to which they are attached. The tarsi are 

 yellow, as are also the anterior tibiae in front and within, the other 

 tibiae being tawny and more or less shaded with dusky. The 

 anterior coxae are yellow in front, the posterior yellow externally. 

 The femora have each a definitely limited suboval yellowish spot 

 below, near the tip, extending two-fifths the length of the femur on 

 the front pair, smaller on middle pair, and shorter and less definite 

 on the posterior. 



From Isosoma tritici, to which this species is most nearly allied, 

 it may be distinguished by its larger size and especially by the far 

 greater amount of tawny and yellow colors. The larva is about 6 

 mm. in length, of a greenish yellow color, distinguished from that 

 of tritici only by its larger size. 



The pupa, from 4.5 to 5 mm. long, varies in color from white 

 in its earlier stages, to the colors of the adult when prepared to 

 emerge. It is distinguished from that of tritici by its larger size 

 and in all our specimens by the presence of wing pads folded around 

 the posterior legs. 



LIFE HISTORY AND DISTRIBUTION. 



Although this species has been observed over so short a period, 

 the facts specified are such as strongly to indicate that it is single- 



