176 



When full-fed the larvsB enter the gronnd and construct long cocoons 

 of brownish silk with which particles of earth are incorporated. The 

 construction of the cocoon is hardly of distinct threads, but seems to 

 be rather of a glutinous nature resembhng silk. The cocoons of the 

 male are 7.5 by 3.5 mm., and of the female 9to 10 by 5 mm. (Fig. 14, (?). 

 There is but one yearly generation. 



Although no observations were made on this point, our knowledge of 

 allied species renders it almost certain that the contracted larvje remain 

 unchanged during the balance of the summer and over winter and do 

 not pupate until shortly before the appearance of the winged insects in 

 the spring. 



The adult insect is about one-third of an inch long and has an ex- 

 panse of wing of about two-thirds of an inch. The males and females 

 differ markedly in shape and coloration. The female (Fig.l4,/) is stout 

 and in general hght yellowish or ochraceous in color. A black spot on 

 the head includes the ocelli, and the thorax is marked with two long- 

 itudinal black stripes. The abdomen is for the most part dark brown 

 or black dorsally except the posterior lateral margin and the extreme 

 tip. The hind feet and antennce are also dark. 



The male (Fig. 14, e) is much more slender and elongate than the fe- 

 male, and is almost black in color, the tip of the abdomen being reddish 

 and part of the legs whitish. The antenna^ of the male are much longer 

 than in the female, equaling the body in length ; they are also stouter 

 and strongly pilose or hairy. The wings in both sexes are large and 

 transparent, and the main or costal veins of the fore-wing and the stigma 

 are pale. 



The wings of this species possess with great uniformity a peculiarity 

 of venation which has been employed to separate a distinct genus 

 {Messa). This consists in that the second submarginal cell receives 

 but a single recurrent vein, instead of two, as is commonly the case in 

 the species of Nematus. This character can not be relied upon, although 

 measurably constant in this species, since in other species with the 

 normal venation of N'ematus this peculiarity sometimes occurs, and not 

 unfrequently a single specimen will display the venation of Messa on 

 one side and of JSfamatus on the other. 



This species was first described by Mr. Edward Norton from a single 

 specimen of the male taken in Maryland (Proc. Entom. Soc. Phila., 

 Vol. Ill, p. 7, 1864). The female was described as a distinct species 

 [Nematus aureopectus) by Mr. Norton several years later, from speci- 

 mens received from Massachusetts, New York, and Pennsylvania. 

 (Trans. Am. Ent. Soc. Vol. I, 1867, p. 219.) The male having been 

 first described, gives the name to the species — N. aureopectus becoming 

 a synonym. 



The natural food-plants of this insect are undoubtedly certain of our 

 native grasses from which it very naturally spreads to cultivated grasses 

 and small grains. 



