68 
LEAFHOPPERS AEEECTING CEREALS, ETC. 
1 ' This species, in common with the others which occur in long and 
short winged forms, are usually very thick, where they occur at all; 
but the eggs, being deposited only upon the Elymus, they are limited 
in their range to a radius of a few feet at most from their host. 
"They have been observed to feed upon the heads of Elymus 
virginicus indiscriminately with those of canadensis where the two 
grasses are near together, or near enough for migration, and in the 
spring, when the larvae were large and abundant and the grasses 
small and inconspicuous, they were found upon everything occurring 
within a reasonable distance of the host." 
Parabolocratus viridis Uhl. 
Parabolocratus viridis Uhl. is a species of wide distribution, occur- 
ring from Massachusetts to northwestern Montana, and has been 
Fig. 8.— Parabolocratus viridis: a, Male; b, female; c, nymph; d, female genitalia; e, male genitalia; /, egg3 
in stem; g, eggs, enlarged; h, single egg, still more enlarged; i, j, young nymphs. All enlarged. (After 
Osborn and Ball.) 
collected by many different observers, though usually in small 
numbers. So far as definite records go, it develops only on the wild 
oats (Stipa spartea). Except for collections extending its known 
range, scarcely any information has been gained since the publication 
of the life-history details in the Proceedings of the Iowa Academy of 
Sciences in 1897, by Osborn and Ball, and I can not do better than 
quote directly from the account published at that time: 
"The adult female is about 7.5 mm. long by 2 mm. broad, with a 
parabolically curved, thin-edged vertex and a stout abdomen, attenu- 
ated posteriorly and extending beyond the rounding elytra. The 
males are smaller and have the vertex shorter and more obtusely 
pointed. The abdomen is smaller and does not extend beyond the 
narrow and nearly parallel-margined elytra. (See fig. 8.) 
