LEAF HOPPERS INJURIOUS TO CEREAL AXD FORAGE CROPS 23 



DISTRIBUTION 



It has a very extensive distribution, having been reported under 

 various names from the New England States and throughout the 

 northern part of the United States and southern Canada and is 

 evidently a form that was reported by Ashmead under the name 

 harrimani from Alaska (i, p. 132) . It is now considered as identi- 

 cal with the widely distributed form occurring in Europe. 



DESCRIPTION 



The adult insect is of a light gray or brownish gray, often pale, 

 but varying so much in color that it has been many times described 

 under different names. It is nearly one-sixth of an inch long and 

 is to be separated from D. ini- 

 mieus by the absence, of definite 

 black spots on the head and tho- 

 rax and by the slightly smaller 

 size. The head, too, is a little 

 more distinctly pointed. (Fig. 6.) 

 The most positive characters are 

 found in the genitalia, the last 

 ventral segment of the female be- 

 ing short, nearly straight on the 

 hind border, while the male valve 

 is very much enlarged and con- 

 vexly rounded, almost covering 

 the plates, the tips of which ap- 

 pear as slight projections beyond 

 its hind border. 



The nymphs are of about the 

 same form as those of inimicus. 

 but differ distinctly in that the 

 body is uniformly light yellow 

 without the black lateral border 

 which is characteristic of inimicus. 

 The head is bluntly angled in 

 front, and in the last nymphal 



citncrp tha wincr r>nrlc; pynnnrl in i Figure 6. — The striate leaf hopper {Del- 



stage me wing pacts expand m a tocephaius striatus) ■. a, Adult xio ; &, 



rather sharp anode back to the face ; c, vertex and pronotum ; d, female 



1 1 -i • i srenitalia ; e. male genitalia ; f. wing ; 



second abdominal segment. J, nymph 



LIFE HISTORY 



The life history of the species has not been determined with com- 

 plete accuracy and is difficult to establish because of the irregularity 

 with which the different generations appear and the overlapping of 

 adult and nymphal stages. On the basis of observations in Iowa, it 

 was believed that there might be three or possibly four generations 

 each year ; and the separation of the broods, so far as they could be 

 determined, showed adults from the middle of May until the last of 

 June, nymphs from the first week in June until the middle of July, 

 adults, again, from the first week in July through August, nymphs 

 through August until the middle of September, and again adults 

 from the middle of September through the season. The evidence is 



