Evaluation of Insecticides for Control of White Grubs, 1996

Tests were conducted on 2 X 2 ft plots at the Purdue University Agronomy Research Center in West Lafayette, IN. The plots were arranged in a RCB design, replicated 5 times. A PVC cylinder (6 inch inside diameter) was buried 4 inches into the soil and projected 1 inch above the soil in the center of each plot. Five 3rd instar JB grubs were infested within each cylinder on 1 Oct. Merit 0.5G was used as the insecticide standard treatment and was applied with a homemade salt shaker on 3 Jul. Orthene and Tame treatments were applied on 4 Oct. Dispersible formulations were applied through a TeeJet® 11003 spray tip attached to a 60-ml plastic syringe at a volume of 2 gal water / 1000 ft2. All plots received 0.5 inch of irrigation immediately after treatment. There were two untreated plots in each replicate. Thatch depth (natural) was 0.13 - 0.25 inches on a silt loam soil. Efficacy was evaluated 25 Oct by extracting the cylinders, separating the soil and grass, and recording the number of live grubs.