-117^ 
gave a complete kill. Seeds of watermelon, corn, tomato, and lettuce treat- 
ed with 0.05 percent of DDT were protected against infestation for 2 months, 
whereas untreated seed was heavily infested.— Cotton at al. ( 120 ). 
The larvae in a dairy building were apparently killed by a DDT residual 
spray.— Boss ( 306 ). 
Larvae appear to be resistant to DDT dust. ^Applied as an aerosol and 
as an oil-base spray under precautions, DDT was not so effective as pyreth- 
rum similarly applied. — Smallman ( 322 ). 
Pleridae 
CollaB eurytheme Boieduval, the alfalfa caterpillar f 
In laboratory tests a 3-percent DDT dust gave complete control in 18 
hours. — Okla. Agr. Expt. Sta. (2JS). 
In laboratory tests Gesarol A-3 dust killed 100 percent of full-grown 
caterpillars. — Hamilton ( 200 ). 
Pieris rapae (L.), the imported cabbage worm 
In greenhouse tests on larvae collected in the field, this species was 
very susceptible to DDT with kills approaching 100 percent by sprays contain- 
ing as little as 2 to k ounces of DDT per 100 imperial gallons. A 15-day-olt 
spray deposit of DDT, which had been kept dry, was just as effective as a 
fresh deposit. Although DDT appeared to have no direct repellent action in 
the sense that larvae avoided the sprayed surfaces, it caused most of the 
larvae to leave the plant soon after they had done a very small amount of 
feeding on treated foliage, or after the insects themselves had been sprayed 
and placed on unsprayed plants.— Boss Q06). 
The imported cabbage worm, the cabbage looper, and the diamondback moth 
were completely controlled by a 5-psreent DDT dust in combination with 5 per- 
cent of yellow copper oxide in pyrophyllite dusted lightly five times during 
the season. The plants in the check plots were so badly riddled that not 
a single edible head was formed. The DDT dust was by far the most effective 
of several insecticides tried. The cabbage plants treated with a DDT com- 
bination were absolutely free from holes and assumed a healthier and con- 
spicuously greener appearance in comparison with all other plots. — Granovsky 
(1§I>- 
Same as for Trichoplusla nl (Hbn.). — Allen and Brunn (71); Apple (75). 
A trial dusting of cabbage with a 3-P«rcent DDT dust gave perfect con- 
trol of cabbage worms, whereas an adjacent row, untreated, was badly riddled 
by worms.— Cartwright (108). 
