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pyre thrum, arsenical, and fluosilieate insecticides. In all cases the 
derris and pyrethrum insecticides proved -ore efficient than the ars^fiicals 
or fluosilicates. 
Roney and Thomas (318) in 1935 reported excellent control of three 
species of cabbage worms, Pieris rapae . Autograoha brassicae , and rlutella 
maculipennis , in Galveston County, Tex., with pyrethrum and derris dusts. 
Diluents used were 300-mesh sulfur, a finely ground clay, and fuller's earth. 
Tests were made with the following derris mixtures: \l) 10 parts of derris 
and 90 parts of sulfur; (2) 10 parts of derris, 15 parts of Powco A, and 75 
parts of sulfur; and (3) 10 parts of derris, 15 parts of Powco A, and 75 
parts of fuller's earth. Each of these mixtures contained 0.5 percent of 
rotenone. It was goneluded that a dust containing 10 percent of derris or 
0.5 percent of rotenone and 90 percent of 300-mesh conditioned sulfur is 
more effective and economical than any other dust or combination used for 
controlling cabbage worms. Derris is slower than pyrethrum in its reaction 
on insects, and little benefit can be seen within 48 hours following an 
application, Pyretirum is limited "ore than derris as to usefulness in dry 
or irrigated areas. 
The South Carolina Agricultural Experiment Station (3 r 8l) in 1935 
reported that experiments of the 1934-35 season indicated that a dust mix- 
ture consisting of/ powder and clay, and containing 0.5 percent of rotenone, 
was approximately as toxic, and in some cases superior to, undiluted calcium 
arsenate, to paris green and lime (1:9), and to synthetic cr olite and 
clay (1:3), when used against the cabbage looper. 
F. L. Thomas (410) in 1935 recommended 1 part of derris containing 5 
percent of rotenone mixed with 9 parts of finely ground, conditioned sulfur 
for the control of cabbage worms including this species. Mr. Thomas ( 411 ) 
in 1936 rep >rted that in Texas derris-sulfur dust (0.5 percent rotenone) 
gave good results in the control of the cabbage looper. 
The Bermuda Department of Agriculture (34) in 1936 reported that two 
dusts containing derris, Cooper's Drymac and Sherwin-'.'illiams' Rotodust, 
were tried against the looper on cabbage. Three applications were made 
and each dust gave a significant degree of control. 
The Colorado Agricultural Experiment Station (73, 74, 7£) in 193^ 
reported that in control of the cabbage looper, the imported cabbage r . 
and the diamondback moth pyr.tl'rum and rotenone gave very satisfactory 
results at reasonable cost. Against cabbage worms pyrethrum- and rotenone- 
bearing materials were more effective as dusts than as spr ys. The imported 
cabbage worm is controlled with pyrethrin- and rotenone-bearing dusts of 
lower strengths than will control the cabbage looper and the diamondback 
moth. Derris and cube dusts wore equally effective n used at the snme 
rotenone content, although the cub... appeared somewhat more erratic 
used during cool weather in the fall. Rotenone ind pyr thrir.9 are known 
to break down mor..- rapidly in direct sunlight; ho , there were no 
significant differences in the results from morn.i - v ning 
applications. 
This Station reported that the 19.35 ii * ion on c ■ uli- 
flower consisted of the cabbage looper, the alfalfa loop, r, • ocnd- 
back moth. These -ire more difficult to kill ' imported cabbage worm. 
