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Erythroneura spp., grape leafhoppers 
A spray of 1 pound of DDT per 100 gallons of water used against 
Po ol Ilia ^aponlca Newm. gave excellent control of leafhoppers on grapes. 
— Hadley and Fleming (196) • 
A 3-percmt DDT dust was effective against leafhoppers on grape.— 
Baseman (203) • 
Promising results in the oontrol of the grape leafhopper were obtained 
in preliminary tests in Ohio with 1.6 pounds of DDT (dissolved in a mix- 
ture of benzene and kerosene whioh was then emulsified) per 100 gallons, 
and in New Jersey with the same formula as used in tests against adults 
of the Japanese beetle.— Baker and Porter (81) • 
One application of DDT, 8 ounoes per 100 imperial gallons of water, 
on July 15 gave complete control of nymphs and prevented breeding for 
the remainder of the season* In a large-soale field test two applications 
of DDT, 16 ounces, at 10-day intervals, gave apparently 100 percent con- 
trol.— Ross (306) . 
Butettix tenellus (Bak.), the beet leafhopper 
In 11 replications of a field experiment with the beet leafhopper on 
sugar beets at Twin Falls, Idaho, 116 pounds per acre of a 5-percent DDT 
dust resulted in an average reduotion in populations of 95 percent after 
3 days and 89 percent after 10 days. A spray containing 4 pounds of 10- 
percent DDT applied at 200 gallons per acre did not give so great a re- 
duction.— White (373 ). 
Macrosteles divisus (Uhl.), the six-spotted leafhopper 
A large carrot field was divided into plots with an area of 1.335 
acres for each of six treatments, two of whioh contained DDT at 20 and 
25 pounds per acre in three applications per season. DDT, 5 percent in 
pyrophyllite, and also 5 percent plus 5 percent of yellow copper oxide 
in pyrophyllite, gave very satisfactory results in controlling this in- 
sect, and a greater percentage of disease-free carrots as oompared with 
other plots.— Gran ovsky (185 , 186 , 187) . 
A 3-peroent DDT dust was oompared with a 1 percent rotenone-25 per- 
cent sulfur dust and an untreated check. Dusts were applied to a com- 
mercial planting of Big Boston lettuoe with a self-propelled 6-row power 
duster using two nozzles per row. Five applications were made at week- 
ly intervals, the first one when the leaves were about 1 inch in diameter. 
The dusts were applied at the rate of 25-30 pounds per acre. A rotenone- 
sulfur dust was substituted for the DDT at the fifth application. Leaf- 
hopper counts 3 days after the third application were as follows: DDT 0.20 
