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tke lead arsenate treatments. Compared with the lead arsenate spray, ro- 
tenone dust will give as good or better immediate kill of both species of 
cabbage worms, but the lead arsenate spray has a greater residual effect 
and v/ill, therefore, remain effective on the plants over a longer period. 
Compared with lead arsenate dust, the rotenone dust gives a better immed- 
iate kill and is about equal or better in residual effect. On Long Island 
rotenone-conto.ining dusts were used largely in 1938 as a substitute for 
pyrethrum dust, and in the absence of serious cabbage looper attack they 
provided the needed protection. 
The North Central States Entomologists ( 509 ) in 1938 discussed the 
control of certain insects by the use of cube and derris. Compton repor- 
ted a heavy infestation of cabbage worms in northern Illinois in 1937, in- 
cluding the imported cabbage worm. Control experiments included tests ex- 
tending over a period of several weeks during the latter part of the sum- 
mer, with lead arsenate, calcium arsenate, cryolite, cube, pyrethrum, and 
several proprietary materials, applied by means of a Niagara traction 
duster with trailer or Bean power sprayer. Potenone-bearing dusts or 
sprays, and lead arsenate dusts or sprays gave the best results in these 
'tests. W. H, White remarked that derris and cube dusts satisfactorily 
controlled the cabbage worm. 
Farks and Pierstorff (324) in 1938 recommended rotenone dust for the 
control of the imported cabbage worm. 
Re id and Bare ( 347 ) in 1938 reported 'that against the imported cab- 
bage worm the 0.5-percent rotenone, the 1-percent rotenone, and the der- 
ris-pyrethrum dust (0,5 percent rotenone +0.2 percent pyrethrins) wero 
significantly different and significantly superior to the pyrethrum. 
Against this species, the 7- and the 10- to 11-day intervals were super- 
ior to the 14-day interval, 
Ro'ark ( 357 )' in 1938 reviewed the comparative action of dorris and 
cube of equal rotenone content on many insects. Kc referred to List and 
Swectman ( 255) who in 1935 tested cube and derris on Picris rapao in 
Colorado and found them to be of equal value when diluted to a rotenone 
content of 0.5 percent ;/Howard, who, in a typewritten report to the Divi- 
sion of Truck Crop and Garden Insect Investigations, of the Bureau of 
Entomology and Plant Quarantine, United States Department of Agriculture, 
in 1935 stated that cube and derris dusts or sprays gave similar result*), 
provided the rotenone content was the same; and to Campbell, who, in a 
typewritten report to the same Division, stated that in field tests on 
cabbage with cube and derris dusts containing 0.5 percent of rotenone, 
derris destroyed 54 percent of the imported cabbage worms, as compared 
with 47.7 percent for cube. In 1935 Campbell (63) reported that cube 
dust was slightly more toxic to the imported cabbage worm than derris 
dust with an oqual rotenone content, 
Agicide DC-4 (rotenone 0,6 percent) at the rate of 4 pounds per 100 
gallons of water (0,003 percont rotenone in spray) killed from 50 to 100 
percent within 96 hours. — Agicide Laboratories (8) in 1939. 
