• - 40 - ' 
of derris or cube re t sprays containing 0.G1 percent rotenone. For 
trol of the cabbage looper it was necessary to use derris or cube dusts con- 
taining 0.4 to 0.5 percent of rotenone, or to use derris or cube root sprays 
containing 0.015 to 0.02 percent of rotenone. Applications were nade every 
10 to 14 days after the vorns appeared in large numbers. There was no sig- 
nificant difference in the degree of control obtained from the use of derris 
root or cube root dusts or sprays, provided the rotenone contents of the in- 
secticides were practically equivalent. The addition of spreaders or stickers 
to derris root suspensions in water applied as sprays secned to increase 
slightly the control obtained. Very little difference in the degree of control 
resulted from the use of a number pf diluents for d,erris or cube dusts, 
H. H, Richardson (340) in 1935 reported that both derris and cube were 
effective against the corraon red spider, on greenhouse plants. Suspensions 
of powdered cube root (5.3 percent of rotenone and 17.3 percent of total carbon 
tetrachloride extractives) at the rate of 0.25 percent (rotenone approximately 
1:8,000) in combination with 0.25 percent by volume cf sulphonated castor oil 
gave high mortality. Cube killed 97.2 percent of the adults and 96.6 percent 
of the nymphs as compared to 99.2 and 99.5 pereent kill, respectively, for 
adults and nymphs caused, by the same concentration of d.erris with 0.5 percent 
sulphonated castor oil. 
The South Carolina Agricultural Experiment Station (386) in 1935 tested 
powdered cube root (rotenone 5 percent) nixed with talc or tobacco powder as 
a dust and also undiluted as a spray against the Mexican bean beetle. Cube 
compared favorably with derris of equal rotenone content. 
Wcigel and Richardson (461) in 1935 reported that the xoroportion of 
sulphonated caster oil is an important factor in the effectiveness of derris 
sprays against red sender. Tests conducted against the roc. spider mite, 
Tetranychus telarius L. , at Barberton, Ohio, indicated, that x spray composed 
of derris root • powder in water, with a rotenone content of approximately 
0.0034 percent, which has not proved entirely effective, showed a .narked in- 
crease in effectiveness when the proportion of sulphonated castor oil was in- 
creased from 1:400 to 1:300. With this proportion, kills of 98.4 percent of 
the adults and 96.4 percent of the nymphs were obtained. It was observed that 
increasing the rotenone content to 0.0052 percent without increasing the pro- 
portion of sulphonated castor oil did not appreciably increase the effective- 
ness. Similar results were obtained when cube ro. t powder in wo.ter, containing 
approximately 0.0095 percent of rotenone, v/as used with the sulphonated castor 
oil. 
The Bureau of Entomology and Plant Quarantine (418) in 1935 assembled 
the results of codling moth investigations during 1934, Gentner at Talent, 
Orcg. , reported that powdered cube root nixed with kaolin, to a rotenone con- 
tent of 1 percent, at a dosage of 10 lbs. to 100 gals., applied at seven-day 
intervals (calyx and first cover of lead arsenate) gave much poorer control 
then lead arsenate on Bartlett pears. 
F. L. Thomas (405) in 1935 rcco:: ended 1 part derris containing 5 
percent rotenone nixed with 9 parts finely ground conditioned sulphur for the 
control of cabbage worms ( Pieris rapae L. , Autographa brassica c Riley, and 
Plutolla maculipcnnis Curtis) and the tomato fruitworm ( Hcliothis o bsolcta Fab.) 
