Oxamyl as a Pretransplant Drench Treatment for Control of the Colorado Potato Beetle (Coleoptera: Chrysomelidae) on Tomato

A liquid formulation of oxamyl (Vydate 2L) was used in a pretransplant drench treatment to control Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), on tomato. Insecticide rates of 0, 473, 946, or 1,892 rol (AI)/378.5 liters of water were applied to greenhouse flats of tomatoes at 0 (day of transplant), 7 or 14 days before transplant. Significantly fewer CPB larvae were recorded in 1982 in plots treated with all rates of Vydate on day of transplant; in 1982 and 1983 significantly less defoliation was observed in plots treated with all rates of Vydate on day of transplant. Phytotoxicity was recorded in 1982 on plots receiving the 473 and 946 ml rate of Vydate on day of transplant or 7 days before transplant. Tomato growers could adapt this procedure to drenching tomato plants in the field to control CPB as they transplant.