-97- 
Effective control of Japanese "beetles attacking silking; corn ear 
tips was obtained with dusts containing 4 percent of DDT or 4 percent 
of a DDT byproduct (primarily a mixture of dichlorodiphenyltri- 
chloroethane, dichlorodiphenyldichloroethane, and the o,j>-isomer of DDT). 
The counts, in beetles per ear, were 0.11 and 0.04, respectively, for 
the treatments, and 6.10 for the control. Corn dusted with these ma- 
terials contained 1*0 and 1*2 European corn borers per stalk, with 2.8 
as the average for the control. In another test the 4 percent DDT dust 
and a spray containing 0.8 pound of DDT per 100 gallons reduced the av- 
erage borer population to 0.6 and 0.8, per stalk as compared with 2«6 
in the control.— ITolfenbarger et al. (3 79 ) . 
"DDT is promising. It is a very effeotive soil poison. We can 
get as good initial control of this beetle in the soil with 15 pounds 
of this roarerial per acre as with 500 pounds of lead arsenate per acre. 
Probably the most important development in respect to the Japanese 
beetle has been the use of DDT, which has proven very effective on the 
larvae in the soil and apparently is more toxic than any other material. 
We have obtained very excellent control of the adults by using one-six- 
teenth of a pound to 100 gallons of water. With one application of 
stronger concentrations we have been able to get protection on peaches 
from these beetles for the full season. The result this year with DDT 
alone is the most promising thing we have obtained yet, but the results 
on control with milky disease are. very good."— Annand (74). 
In laboratory tests as little as 1/16 pound of DDT in 100 gallons 
of water was as efficient as 6 pounds of le*ad arsenate. In combination 
with most fungicides it was slightly less effective. In field tests 
one to three sprays of DDT (micronized with equal parts of pyrophyllite, 
and with glue as a wetting agent), applied at the rate of 1 pound per 
100 gallons, gave almost complete control of the beetles on peaches, 
early apples, grapes, blueberries, ornamental and shade trees, and shrubs. 
Applications after the first spray were necessary largely to protect new 
growth. DDT applied in spray or in dust form was also very effective 
in soil treatments against the grubs. In tests with 28 different soils 
25 pounds of DDT per acre was more effective against third-instar larvae 
than 1,000 pounds of lead arsenate, and the effectiveness of the DDT in 
the soil was not ohanged during the period of the tests*— Baker and 
Porter (81) . 
A DDT aerosol gave excellent kills.— Ditman (133 ) . 
Three sprays of DDT (same treatment as for grape leafhopper) gave 
very good control of Japanese beetle on grapes.~N. J. Agr. Sept. Sta. 
(275). 
After an application of a DDT spray to sweet grapes (New York 
Muscats) wasps, bees, and Japanese beetles disappeared.— Bromley (96) • 
