78 LEAFHOPPERS AFFECTING CEREALS. ETC. 
DISTRIBUTION'. 
The distribution of the species, as here limited, covers a large part 
if not the entire territory of the northern and eastern United States, 
as material has been examined all the way from New York to Wash- 
ington, D. C. and south to South Carolina and Georgia, and west to 
Xew Mexico. In this distribution there seems no particular limit to 
the different varieties, but any of them may occur within the different 
territorial limits. 
FOOD PLANTS. 
It has a considerable range of food plants, but there is apparently 
a quite distinct preference for the annual grasses, such as foxtail or 
panic grasses and others, but it migrates very readily from these into 
wheat, oats, and other cereals and also occurs very commonly in 
bluegrass and timothy, especially after the withering of the annual 
grasses upon which it has fed earlier in the season. On this account 
it is one of the most troublesome forms occurring in fall wheat and 
oats, since it has developed in great numbers upon early grasses and 
with the failing of these as a food supply is forced to migrate, and this 
migration, coming with the appearance of the young and succulent 
plants of wheat and oats, affords the most attractive bait. 
DESCRIPTION AND LIFE-HISTORY NOTES. 
The adults (see fig. 14) are to be recognized by the rather short 
vertex, the margins of which are plainly rounded, and especially by 
a distinct row of black spots which lies next the border of the upper 
part of the head and bends down alongside the eyes in front . Of these 
spots there are four on the upper part between the ocelli, usually one 
on each ocellus, and two on each side between the ocellus and base of 
the antenna?. Other spots may occur with greater or less distinctness 
on the upper part of the head, but are too variable to constitute good 
characters for recognition. The face is usually marked with numer- 
ous black bars; sometimes it is entirely black or with only a few light 
streaks on the lower portion. The upper part of the body, the thorax, 
and the wings vary greatlv in intensitv of color, sometimes bennr very 
light, occurring without any distinct markings, and sometimes pre- 
senting distinct dark-brownish markings, especially along the veins 
of the forewing. The forewing presents a peculiar diversity in the 
development of the cross veins, some examples presenting two dis- 
tinct veins, while others, apparently identical in every other respect, 
are wanting in the hinder one of these cross veins. These two forms 
not only agree in other respects but are evidently derived from nymphs 
which are idistinguishable. 
The nymph is rather broad and resembles in characters the Delto- 
cephalus Jiavicosta, but is slightly narrower and not so distinctly 
