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Cube and derris dust .mixtures containing from 1 to 2 percent 
of rotenone usually gave good control, "but the results were less con- 
sistent than the derris and cube spray treatments. 
Dudley and Bronson of the Madison, Wis., station of the Bureau 
of Entomology and Plant Quarantine reported that in a large replicated 
plot experiment satisfactory aphid control was secured "by treatment 
with derris spray, derris dust mixture, and nicotine vapor, "but not with 
nicotine dust. The largest increase in the yield of shelled peas 
resulted from the derris dust treatments, with the nicotine vapor 
treatment second, and the derris spray treatment third. The plots 
treated with nicotine dust yielded less than the checks. Derris spray 
was used at a rotenone concentration of 0.01 percent plus sodium oleyl 
sulphate and in some cases also 1 percent aliphatic thiocyanate. 
Hamilton (185) in 1938 reported the results of tests of cube and 
derris powders (4$ rotenone and 16 to 18fo total extractives) applied 
as a spray at the rate of 4 pounds per 100 gallons, with the addition 
of 4 pounds of rosin residue emulsion. 
Cube powder appeared to be as effective as derris powder in the 
rosin emulsion spray, both as a contact insecticide and as a repellent. 
These tests were made by members of the National Shade Tree 
Conference under a cooperative project with the Hercules Powder Company, 
manufacturers of rosin residue, and five of the principal suppliers of 
derris and cube powders. Sufficient spray material to make from 500 to 
1000 gallons of diluted spray was sent to each of 38 cooperators in 14 
States, together with instructions for using the spray and a report 
blank to be used in giving the results of the tests. 
The results against insects were as follows J 
Cankerworms (various species of Lepidoptera, G-eometridae) on 
various shade trees were satisfactorily controlled. The spray acts as 
a contact poison and as a repellent. The effective period is 3 days 
to 2 weeks. One spraying before larvae were more than two- thirds grown 
gave good kill. 
Tent caterpillars ( Malacosoma americana P., Lepidoptera, 
Lasiocampidae) on wild cherry, apple, and hawthorn trees were satis- 
factorily controlled. The spray acts as a contact poison and as a 
repellent. The effective period is 6 to 8 days. Caterpillars would not 
feed on sprayed foliage. 
Pall webw'orms ( Hyphantria cunea Drury, Lepidoptera, Arctiidae) 
on walnut trees were satisfactorily controlled. The spray acts as a 
contact poison, the effective period being 6 days. There was 100 percent 
kill of larvae in sprayed webs. 
