Laboratory Tests with Insect Growth Regulators Against Larvae of the Darksided Cutworm, 1986

Two insect growth regulators, Alsystin (triflumuron) and HOE 000522, were evaluated in the laboratory with treated tobacco leaves against darksided cutworms. Tests were conducted on laboratory-reared third- and fifth-instar larvae. A randomized block design of 7 treatments for each tested larval stage was used with 5 replications. Larvae in each tested stage were separated into groups of 10 and placed in 4-inch Petri dishes. Tobacco leaves were dipped in 3 rates of water suspensions of each material. The treated leaves were air dried and placed in the Petri dishes with the larvae. After 3 days, the treated leaves were replaced every other day with fresh, untreated leaves. Rearing was conducted at room temperature (72-74°F) and 16 h photoperiod. Mortality was assessed daily for , 15 days by counting the number of dead larvae in each dish. Thereafter, the number of living pupae and emerged adults were recorded for each treatment. Results have been presented as the number and percentage of dead or live cutworms in each treatment.