Derris (rotenone 5.4 
percent; total extrac-' 
tives 15,5 percent) as 
a dust 
Derris-talc dust 
(rotenone 1 percent) 
Derris-talc dust 
(rotenone 0.5 percent) 
Cube (rotenone 4.4 
percent; total extrac- 
tives 20.7 percent) as 
a dust 
-128- 
Test insect 
Diamondback oabbage worn 
Fourth ins tar 
Second ins tar 
Fourth instar 
Second instar 
Fourth instar 
Fourth instar 
Second instar 
Dosage 
per cm. 
Mortality 
.in 48 hours 
Hicrograns Percent 
140 
140 
170 
170 
140 
140 
140 
100 
100 
100 
100 
100 
100 
100 
M. 1. d. of derris and cube powders in 48 hours 
Insect 
Instar 
Fifth 
Fourth j Third Second \ First 
Diamondback cabbage worm 
140 (0.5) 
140 (0.5) 
Agicide DC-4 (rotenone 0.6 percent) at the rate of 4 pounds per 100 
gallons of v/ater (0.003 percent rotenone in spray) killed from 50 to 100 
percent within 96 hours. — Agicide Laboratories (_§_) in 1S39. 
In experiments with insecticides derris dust (l percent rotenone) or 
paris green plus wood ash (2:15) gave 99- to 100-percent mortality cf tho 
larvae. Paris green is cheaper than derris, but is dangerous to use. and 
stains the vegetables. Pyrethrum powder (1.3 percent pyrethrins) plus 
wood ash (1:6) gave almost as good results. The pyrethrum had a mere, 
rapid effect on the larvae than the derris, but did not protect the plants 
so long. The insecticides should bo applied four times at -weekly inter- 
vals and at the rate of 22-1/2 pounds per acre. — Ghesquiere ( 158 ) in 
1939. 
Haude, in advertising literature publishod by John Powell and Co., 
New York, N. Y., in 1939 recommended cube or derris dust (0.5 porcont 
rotenone) at 25 to 30 pounds por ucrc or spray (5 pounds of powder of 4 
percent rotenone contont) por 100 gallons of water. 
