on single 3- by 50-ft. rows of cabbage plants in randomized blocks. Unless 
otherwise indicated, the compounds were formulated as emulsifiable concen- 
trates and were applied as sprays with a hand-operated knapsack sprayer at 
approximately 50 gallons per acre. Five applications were made at 7-day 
intervals each spring beginning early in May and extending to early in June. 
With the exception of 1964, five applications were also made at 7-day intervals 
in the fall, beginning in mid-September and extending to mid-October. In 1964, 
seven applications were made at 7-day intervals between mid-September and 
mid-November. 
Evaluation of the compounds was based on the number of surviving cater- 
pillars, by species, on 10 plants per plot on the second day after each spray 
application; also, on the degree of caterpillar injury to the plants at harvest. 
Plant damage, was estimated according to a system of classification reported by 
Reid (1940) .4/ Plants whose firm head and four wrapper leaves were free of 
visible caterpillar feeding were recorded as being in class 1. Class 3 plants 
were those with firm heads and four wrapper leaves sufficiently damaged by 
caterpillars to be ineligible for U.S. grade No. l. 
RESULTS 
Spring Treatments 
Results of spring treatments are summarized in table 1. In 1963, each 
insecticide tested was effective against moderate infestations of the imported 
cabbageworm and diamondback moth [ Plutella maculipennis (Curtis)/. Endrin at 
0.4 pound/acre and Monsanto compounds CP-10273 and CP-40294 each at 1.0 
pound/acre were superior in all respects to naled against a moderate infesta- 
tion of the cabbage looper. ene (Bayer 44646) at 1.0 pound/acre was 
superior to naled in reducing the number of class 3 plants and tended to be 
more effective than naled in reducing the looper population and in the pro- 
duction of class 1 plants. Surviving cabbage looper populations were 
significantly higher on plots sprayed with Bayer 41831 and Compound 4072 than 
on naled-treated plots. However, the plant protection provided by these. 
compounds was equal to that provided by naled. The addition of methyl 
parathion to the endrin spray did not increase its effectiveness significantly. 
Bayer 41831 and Compound 4072 caused severe injury to the plant foliage. 
Monsanto CP-40273 caused slight injury to the head and surrounding leaves. 
In 1964, treatments with American Cyanamid CL-4+7470 and Azodrir® (She11 
SD-9129) resulted in the highest production of class 1 plants, each giving 
adequate control of the cabbage looper population, which averaged 2 loopers 
per plant in the untreated plots. Bayer 25141 and methyl parathion were 
superior to endosulfan in the production of class 1 plants and were superior to 
4/ Reid, W. J., Jr. A System of Classifying Cabbage According to the 
Extent of Caterpillar Injury. U.S. Dept. Agr. Bur. Ent. and Plant Quar. 
Et-160, 7 pp. 1940. 
Ee 
