Cabbage Looper and imported Cabbageworm Control On Cabbage, 1977

Abstract

Abstract Eli Lilly and Co.’s experimental molt inhibiting insecticide EL-494 was tested against cabbage looper and imported cabbageworm. Treatments were applied to ‘Late Flat Dutch’ cabbages planted June 10at the University of Minnesota Rosemount Experiment Station. Field plots were single, 25-ft rows spaced 40 inches apart, with 18-inch in-row plant spacing. The insecticide was applied August 11 for the first test and August 19 for the second with a 2-gallon hand-operated compressed-air sprayer in 137 gal water/acre at ca 40 psi. Different plots were used for each test. The day after spraying cabbage leaves were cut from treated plants and from untreated checks, and larvae of both insect species were collected from untreated plants in an adjacent plot. The larvae used in the first test were fifth instar, in the second test the cabbage loopers were third instar and the imported cabbageworm fourth instar. Leaves were harvested from the treatments 1 day after application of thesprays, placed in plastic bags and held at 4°C until used. In the laboratory previously unexposed larvae were placed individually in petri dishes on ca 4 square inches of cabbage leaf. Each test consisted of 10 larvae and was replicated 3 times. Insects were examined daily and food changed as necessary.