FIELD-EVALUATION OF STEINERNEMA-CARPOCAPSAE (RHABDITIDA, STEINERNEMATIDAE) AGAINST BLACK CUTWORM (LEPIDOPTERA, NOCTUIDAE) LARVAE IN FIELD CORN

An entomopathogenic nematode, Steinernema carpocapsae (Weiser) All strain (BioVector(R), applied at two rates (1.25 and 2.5 X 10(9) nematodes/ha) was compared with several registered insecticides for controlling black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), larvae during the 1991 growing season in Illinois. Fonofos, tefluthrin and chlorpyrifos were applied at planting time; permethrin and the two rates of nematodes were applied as postemergence rescue treatments. The nematodes generally performed as well as or better than the conventional insecticides in controlling black cutworm larval injury to seedling corn. Bioassays with black cutworm larvae showed that nematode efficacy was lost 8 days after application in the field. Entomopathogenic nematodes hold promise for controlling black cutworms in corn, particularly for corn grown under irrigation.