Control of Black Cutworms on a Bentgrass Golf Course Fairway, 1994

Conventional and biological insecticides were evaluated for control of BCW larvae on a golf course creeping bentgrass fairway in Lincoln, NE. The turf (100% creeping bentgrass) was maintained at a mowing height of 0.5 inches. Thatch accumulation (finger compressed) in the plot area was 0.125 inches. Field conditions at the study site were: soil type, silty clay loam; soil organic matter, 3-5%; soil pH, 6.7; water pH, 7.0. Soil moisture was adequate throughout the study. Plots were 6 × 8 ft and the experimental design was an RCB with 4 replications. Insecticide treatments were applied on 14 Jul 1994. Liquid insecticides were applied using a CO2 sprayer with an Lf-4 nozzle at 40 psi and delivering 5 gal finished spray/1000 ft2. Following applications, plots were irrigated with 0.5 inch of water. A total of 1.78 inch of rain fell during the post treatment period. Treatments were evaluated 4 DAT (18 Jul) by drenching two 6 ft2 areas in each plot with 0.5 oz. of lemon-scented dish washing detergent per gal of water. BCW were recorded as they appeared on the turf surface. Pretreatment estimated life stages were: 26% under 3rd instar, 7% 3rd instar, 16% 4th instar, 41% 5th instar, 7% 6th instar, and 3% 7th instar.