-90- 
G. D, Jones ( 224 ) stated that in 1938 in instructions issued for the 
control of garden pests a dust containing 0.5 to 1.0 percent of rotenone 
had proved satisfactory in controlling the tomato fruitworm. As diluents 
use clay, talc, cheap flour, or sulfur, and prepare by mixing 1 part of 
derris to 4 to 8 parts of the carrier. Hydrated lime cannot be used as a 
carrier because of harmful chemical reactions. 
The Louisiana Agricultural Experiment Station ( 258 ) in 1938 published 
a summary of entomological progress, in which C. E. Smith reported that 
against larvae of the corn earworm the inorganic materials (paris green, 
calcium arsenate, and cryolite) were superior to the organic materials 
(derris-root powder and pyre thrum-flowers powder). 
JMichelbacher and Essig ( 274 ) in 1938 described tests against the 
fruitworm on tomatoes. The materials, replicated twice, were applied to 
plots approximately 0.1 acre in area and were placed along the edge of the 
experimental series located at San Jose and Santa Clara, Calif. A dust 
containing 80 percent of sulfur and 20 percent of derris (0.75 percent 
rotenone) was ineffective. 
Against the corn earworm, none of the synthetic or plant insecticides, 
including derris, compared in toxicity to lead arsenate. — New Jersey 
Agricultural Experiment Station ( 294 ) in 1938. 
The North Central States Entomologists ( 309 ) in 1938 discussed the 
control of certain insects by the use of cube and derris. W, H. White re- 
marked that cube and derris do not control the corn earworm. 
Wilcox and Stone ( 4-83 ) in 1938 reported that cube-dust mixtures con- 
taining as high as 2 percent of rotenone gave inferior results and are not 
recommended for use against the tomato fruitworm. 
Haude, in advertising literature by John Powell and Co., New York, N, Y., 
in 1939, wrote that preliminary tests indicated that rotenone dusts are ef- 
fective for the control of the young cotton bollv/orms, especially if sul- 
fur is used as the diluent. A 0.5-percent-rotenone dust applied before 
the infestation became heavy was effective against young tomato f ruitworms. 
Early applications at 20 to 25 pounds per aero, repeated at weekly or 10-day 
intervals, and complete coverage are essential. 
Although rotenone dust has been recommended for controlling this in- 
sect on corn, tomato, and eggplant, experimental results have been very in- 
consistent. The Texas and Illinois State Experiment Stations hevo shown 
that a 0,5-percont-rotenone dust is effective against the early stages, but 
this has not been substantiated by work in Now York, New Jersey, and Cali- 
fornia. When the worms are in the early stages, a dust containing 0.5 per- 
cent of rotcnono with sulfur as the diluent is rocommondod. 
Moreland and Gaines ( 281 ) in 1939 reported the results of tosts mix do 
in 1936 in the Brazos River bottoms, Tex., with dust insecticides for the 
control of the bollworm on cotton. Calcium arsenate, culciu'n arsenate 
plus paris green (5 and 10 percent), calcium arsenate plus oube (0,8 per- 
cent rotenone in the mixture), and calcium arsenate plus 50 percent of 
