Control of Early Instar Black Cutworm Larvae with Spinosad Formulations and Dursban, 1997

Abstract

Abstract The rial was conducted at Hanover Country Club, Hanover, NH on a bentgrass nursery. One hundred 3rd-instar larvae per treatment were placed in a PVC cylinder on 9 Jul. Treatments in all cylinders were applied on 10 Jul. There were a total of 12 treatments, replicated 4 times, with 3 rating dates, in a RCB design. The insecticides were applied using 32-oz, hand-held pump sprayers. The volume of water and insecticide mixture per cylinder was 2 gal/1000 ft2. vVeather conditions were as follows: air temp, 68°F; sky, mostly sunny; wind, light. Soil conditions were as follows: surface temp, 78°F; at 1-inch depth, 74°F; at 2-inch depth, 70°F; texture, loam; sand, 64%; silt, 28%; clay, 8%; moisture, 21%; organic matter, 4.8%; pH, 7.3. The trial was rated on 11 Jul, 13 lul, and 17 Jul by applying to each cylinder a dilution of Joy dish soap and water to each cylinder to force live larvae to the surface for counting. During : he rating period, peak daytime surface temperatures were hot (90°F).