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Applications were made on May 11-13, May 21-22, and May 27. In the 
third application, however, only those materials were used which would 
leave no poisonous residue on the berries. Differences in the amount 
of injury that could be detected in the various plots on May 21 were 
slight, but these differences increased as the season advanced. On 
June 10, 600 leaflets from each of the more outstanding plots were 
examined for leaf roller injury. 
The powdered cube root, although it contained the same amount 
of rotenone (4 percent) and was used in the same manner (diluted 1 to 
7 with gypsum), was significantly less effective than powdered derris 
root (47.2 percent control for cube; 75.7 percent control for derris). 
Knowlton and Sorenscn (246) of the Utah .Agricultural Experiment 
Station in 1937 reported that cube or derris sprays applied with 
properly adapted power spray equipment at a pressure of at least 
300 pounds, has given good control of the pea aphid in several States. 
G-ound cube root or derris powder with a 4 percent rotenone content 
should be used at the re to of 3 pounds to 100 gallons of water. Other 
strengths of dust should be diluted to a like strength. To be 
most effective, such a sp?'ay should be applied on a quiet, warm day, 
and before the pea aphid causes noticeable injury to the plants. 
The E-under.bor?el«Bestri jdings-Commissie (362) of Holland in 
1937 recommended aqueous suspensions of derris root for the effective 
control of the cattle grub. Derris powder containing some Lonchocarpus 
powder is encountered in commercial derris products. Although 
Lonchocarpus powder contains rotenone, and frequently has as high a 
rotenone content as derris, it is, nevertheless, much less effective 
than derris. Experiments at the Koloniaal Instituut showed derris 
to be from 1.5 to 2 times as effective as Lonchocarpus, in a large 
number of comparative biological tests. 
The Bureau of Entomology and Plant Quarantine (423) in its 
annual report for 1937 reported that sprays or dusts of cube or derris 
control the Mexican bean beetle at a minimum cost. Cube or derris 
dusts plus sodium oleyl sulphate are effective against pea aphids 
and leave no rotenone or other 'constituent? in peas taken from 
treated plants. Cube and derris dusts gave negative results against 
the corn earworm on lima beans. Tobacco flea beetles, Epi trix 
parvula P. and E. cucumeris Harr. , are controlled by cube or derris 
dusts containing sterilized tobacco dust as the diluent. Cube dust 
did not control thrips on cotton. 
Wallace (454), Secretary of Agriculture of the United States 
of America, in the United States Department of Agriculture Yearbook 
of Agriculture, 1937. wrote as follows: 
"Laboratory and field tests with organic insecticides, 
particularly- derris and cube, have brought many modifications ii 
the recommendations for the control of certain insect pests. I 1 
