80 
LEAFHOPPERS AFFECTING CEREALS, ETC. 
one near the tip of the vertex and a larger round one above the 
ocellus, usually quite conspicuous. The color is pallid and the veins 
are usually but slightly apparent; the wings extend beyond the 
abdomen; the length is about 4 mm. 
This species occurs upon the annual grasses and has a very general 
distribution, especially in the southern part of the "United States, 
from Florida to southern California. It sometimes appears in great 
abundance, as shown by the collections of Mr. C. N. Ainslie in Texas 
and New Mexico, and by the writer in California, and may be a 
distinctly economic species passing from annual grasses or weeds to 
cultivated crops. The most 
evident method of control, 
with our present knowledge of 
the species, is the elimination 
b Nv ^J|^' °f the host grasses during the 
early part of the summer. 
Deltocephalus fusclner- 
vosus Van D. 
Deltocephalus fuscinervosus 
Van D. is a southwestern 
form closely related to D. 
nigrifrons, but with darker 
coloration above and a more 
complete fusion of the spots 
on the vertex. (See fig. 15.) 
Fig. 15. — Deltocephalus fvscinervosvs: a, Adult; b, face; c, 
vertex and prone-turn; d, female genitalia; e, male gen- 
italia; /, wing. AH enlarged. (Original) 
The genitalia are quite similar, and it is probable that the two forms 
stand as divergent branches from a common stock. 
This form occurs abundantly in the wild grasses of southern Cali- 
fornia and is found as far north as San Francisco. 
Deltocephalus coxfiguratus Uhl. 
Deltoceplialus configuratus was described in 1878 by Prof. Uhler 
from specimens which were collected in one of the geological surveys 
through the Kocky Mountains region, but no intimation was given 
of its economic importance and no statement of any such importance 
occurs until the report on the work of Iowa species in 1896. At that 
time it was recognized as important, as it was taken in great abun- 
dance in both the nymphal and adult forms in grasses. The species has 
a wide distribution throughout the northern part of the United States 
and probably in the southern portion of Canada. Records from 
various sources show it to occur from Mount Washington, N. H., 
through New York and northern Ohio, Illinois, Iowa, the Dakotas, 
