-55- 
Strong in 1936, in a* letter to the Chief of the Bureau of Plant In- 
dustry transmitted the results of tests with'devil' s-shoestrings on various 
insects. A comparison of this insecticide with derris was made against 
codling moth larvae at Beltsville, Md.," using Siegler's apple-plug method, 
with the following results: 
Treatment 
Larvae 
Successful 
entrances 
None 
Tephrosia virginiana 
(1.72 percent rotenone, 7.5 percent 
total extractives, carbon tetra- 
chloride) 4 pounds in 10Q gallons 
Derris root 
(3,6 percent rotenone, 15.6 percent 
total extractives, carbon tetra- 
chloride) 2 pounds in 100 gallons 
Number 
226 
40 
Percent 
S5 
85 
41 
71 
Lead arsenate was not used in this series but, on the average, tests 
carried on by this technique gave approximately 40 percent of successful 
entrances. 
The United States Department of Agriculture on January 13, 1936, 
issued a press release which called attention to certain disadvantages 
that bar the use of rotenone insecticides for some types of insects. 
Derris is not effective against all insects. / \ though toxic to codling 
moth larvae in the laboratory, rotenone preparations, exposed to light 
and air in a thin spray film, decompose too rapidly for economical use. 
Allman (_12) in 1938 reported the results of a series of experiments 
in commercial control, carried out during the 1936-57 season at Maimuru 
(Young) in Australia, the tests including four varieties. The derris and 
white-oil emulsion specially prepared for the test was ineffective at 
1:100, and a residue of derris usually ran to the calyx end of the fruit, 
resulting in oil staining. Excessive use of the usual white oils has 
caused a somewhat similar' condition, but the presence of the derris pow- 
der apparently encouraged this tendency to oil-burn. 
Infestation on apple, pear, and plum was- mitigated by a product con- 
taining 12 percent of powdered Lonchocarpus nicou root (6 percent rote- 
none) and 88 percent of talcum, according to Etablissements Rotenia, in 
a letter to R-. C. Roark in 1938. 
The New York County Agents'. Training School ( 298 ) in 1938 heard re- 
ports on rotenone products. Cube was not a satisfactory control in a 
moderately Infested orchard. 
