Control of the Southern Masked Chafer at the Purdue University Agronomy Research Center, W. Lafayette, In, 1993

All treatments were applied to a 4 ft2 area (plot), replicated five times in a RCB design. A PVC cylinder (6 inch inside diam) was buried 4 inches into the soil and projected 1 inch above the soil in the center of each plot. Five third-instar grubs were infested within each cylinder, with the exception of plots treated with Merit which were infested with second-instar grubs, 2 d prior to treatment, 2 Sep. Dispersible formulations were applied at 2 gal/1000 ft2 using a 2 pint squeeze bottle with a mist nozzle. Granular formulations were applied with a homemade salt shaker. All plots with the exception of those treated with Triumph, Diazinon, and one Orthene 15G treatment (not watered-in), received 0.5 inches of irrigation immediately after treatment. Triumph and Diazinon treatments were irrigated with 0.5 inches of water 24 h after treatment. Conditions at the time of treatment were: air temp., 22°C; soil temp, at 1 inch, 20°C; thatch depth (natural), 0.13-0.25 inches; soil texture, silt loam; RH 92%; wind speed 3-5 mph. Turf in PVC cylinders that was treated with chlorpyrifos (FN 5354 and NAF-53) and its associated wetting agent (HM 8902) was brought in from another location and had a thatch layer of 0.5 inches. Efficacy was evaluated 30 DAT by extracting the cylinders, separating the soil and grass, and recording the number of live grubs.