-126* 
. The Texas Agricultural Experiment Station ( 404 ) in .1336 reported that 
derris v/ac considerably more effective than cute against the larvae, re- 
gardless of the carrier used, according to tests, conducted at Tfeslaco and 
Vfinterhaven in January 1935. The derris mixtures and the cube mixtures 
were more effective against the larvae of this moth than against the cab- 
bage looper. On the average, derris-sulfur (15:85) or cube-sulfur (15:85) 
containing 0,75 percent of rotencne gave better control of cabbage worms 
than either lead arsenate or barium fluosilicate in the lower Rio Grande 
Valley, the Vi/inter Garden, or Galveston County, 
The Colorado Agricultural Experiment Station (76) in 1S37 reported 
that the larvae of this species rank about midway between the imported cab- 
bage worm and the cabbage looper in resistance to pyrethrins and rotenone. 
Hutson ( 209 ) in 1937 recommended derris dusts or sprays for control. 
Kelsall and Stultz (234 ) in 1937 reported laboratory tests of dorris 
(4 percent rotenone) as a dust. Gypsum was used as a diluent. Results 
were as follows: 
Concentration of derris 
Percent 
Mortality in ^ 
Percent 
- day 
5 
12,5 

40 
Craufurd-Benson (85) in 1938 reported that experiments were made in 
breeding this species in a greenhouse, under standardized conditions for 
use as a test insect for evaluating derris insecticides by the author's 
dipping method. The result was a failure, because larvae of the same age 
showed wide variation in size and instar, and oven with careful grading 
for size and age the results were still unreliable,. 
Dibble, of the Michigan Agriculture Extension Service, in a "bug 
flash" in 1938, recommended pyrethrum or derris dusts or sprays for con- 
trol on cauliflower and cabbage. 
Gui ( 172 ) in 1938 reported that for protection against cabbage worms, 
including this species, the cabbage should be dusted or sprayed at 10-day 
intervals with paris green or dorris powder. Derris-powder dusts should 
contain not less than 0,5 percent of rotenone. One pound of derris pow- 
der (4 percent rotenone) should be used to 7 pounds of the diluent. De- 
sirable diluents are flour, talc, diatomaceous clay, dusting gypsum, and 
finely ground tobacco stems. Derris-powder sprays should consist of 1.5 
pounds of derris powder containing 4 percent of rotencne in 50 gallons of 
water. When other grades of derris powder are used, dosage should be so 
calculated that the spray contains 0,015 percent of rotenone. A spreader 
and sticker should be used. Federal regulations prohibit excessive resi- 
dues of poison on marketed cabbage; therefore, paris green should not be 
applied after the heads begin to form. Derris powder may be used after 
that date or throughout the season if desired. There are no regulati 
concerning residues of rotenone on fruits and vegetables. 
