48 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
were coming in in numbers this spray would need to be followed by a 
second one 10 days later. 
Several mechanical devices have been used to catch different leaf- 
hoppers, and no doubt several of these could be used against this insect 
with advantage. The tar pan, or " hopper-dozer," drawn over the 
beets two or three times in the first few weeks would capture a large 
number of them. The females, before the eggs are laid, are quite 
heavy and do not jump or fly as readily as the males and would be 
easily caught. A modified form of this machine, consisting of a 
couj^le of tarred wings to be drawn along on each side of a row of 
beets, while a drag agitated the tops and caused the insects to fly, 
would probably capture more than the simpler tar-pan. 
If the insects appeared while the beets were quite small, they could 
be largely destroyed by rolling when the weather was cold or damp 
and the insects sluggish. 
A number of preventive measures may be used to assist the beets 
in withstanding the attack of the leafhoppers. In some sections early 
planting will produce beets large enough to shade the ground by the 
time the beet leafhoppers appear, and thus reduce the temperature 
below the danger line. In a few places, like the Grand Junction dis- 
trict in Colorado and Sevier County in Utah, early planting alone 
would not avail, as the insects appear soon after the earliest beets 
come through the ground. For such sections early and frequent irri- 
gations would assist in keeping the ground cool until the beets grew 
large enough to shade it and thus take care of themselves. 
All preventive measures will depend for success upon some method 
of controlling the temperature in the field so that the ground may not 
be hot and dry at the time the leafhoppers appear. 
BIBLIOGRAPHICAL REFERENCES. 
1895. Gillette, C. P., and C. F. Baker. — A preliminary list of the Hemiptera 
of Colorado.<Bul. 31, Colo. Agric. Exp. Sta., p. 100. 
On sugar beets in Colorado. Mention as Thamnotettix tenellus Uhl. MSS. 
1896. Baker, C. F — New Hemiptera. < Psyche, Vol. VII, Suppl., p. 24. 
Species described from New Mexico as Thamnotettix tenellus n. sp. 
1900. Forbes, S. A., and C. A. Hart. — The economic entomology of the sugar 
beet. <Bul. 60, 111. Agric. Exp. Sta., pp. 423, 523. 
On sugar beets in Colorado. Mention as Eutettix tenella Bak. 
1903. Chittenden, F. H.— Yearbook U. S. Dept. Agric. f. 1902, p. 730, 1903. 
Mention. " Reported as injurious to sugar beet in Arizona." 
1906. Howard, L. O— Yearbook U. S. Dept. Agric. f. 1905, p. 630, 1906. 
Injury in Utab. Mention as Eutettix striata Ball. 
1907. Ball, E. D. — Report of the entomologist. <16th Rept. Utah Agric. Exp. 
Sta., p. 16. 
Character of injury and damages in 1905. Mention as Eutettix tenella Bak. 
1907. Ball, E. D. — The genus Eutettix. <Proc. Davenport Acad. Sei., Vol. VII, 
pp. 27-94, Pis. I-IV. 
A systematic and economic review of the group, with original illustrations. 
