THE INIMICAL LEAFHOPPER. "3 
century ago, but the next mention of it from an economic standpoint 
appears to have been in 1884, when Prof. Forbes speaks of it as 
occurring in corn and also injuring wheat in connection with two 
other species of leafhoppers which he described in detail. Dr. Fitch 
merely mentions it in his list published in 1851, but does not seem to 
have recognized its economic importance. Other notice of it does 
not appear until 1890, when, in a report to the Division of Ento- 
mology, I called attention to its abundance and its destructiveness in 
Iowa in connection with other 
insects. I also described the 
general appearance of the larva 
in 1891 and published some de- 
tails of the life history in 1892 
and 1893. Also, in Bulletin 19 
of the Iowa Agricultural Experi- 
ment Station, I described the 
treatment for it, especially with 
the hopperdozer. Prof. F. M. 
Webster, in 1896, mentioned the 
life history, etc., in Bulletin 68 
of the Ohio Agricultural Experi- 
ment Station. 
DISTRIBUTION. 
The species is one of very 
wide distribution in America 
(see fig. 13) and appears to be 
confined to this country. Van 
Duzee, in his catalogue, credited 
it to Canada and the United Fig. 11.—The inimical leafhopper (Dellocephalus in- 
States west to the Rocky Moun- imicus): a, Adult; b, face; c, vertex and pronotum; 
tuins, but later records indicate ele fn «mae gta: J, Sen: 
its general occurrence all the 
way from Maine to Washington State and south at least to Tennessee 
and southwest to Kansas. 
In the summer of 1909 I found it on grass at Ames, Lowa; in the 
Missouri Valley in grass, timothy, wheat, and alfalfa; in South 
Dakota at Vermillion, and at Brookings in wheat, bluegrass, timothy, 
and wild grass; in North Dakota at Fargo, June 25 to 28, full-grown 
nymphs and adults, in pasture, especially an old brome-grass pasture 
and a timothy-clover pasture. At Ada, Minn., July 2, in wheat fields 
and grass; at Dickinson, N. Dak., July 8, in alfalfa; at Mammoth Hot 
Springs, Yellowstone Park, July 14, in irrigated plat (?%); at Bozeman 
and Missoula, Mont., July 15 and 16, on grass; at Moscow, Idaho, 
and Pullman, Wash., on timothy, festuca, and alfalfa; at Kalispell, 
