Bioassay Evaluation of Japanese Beetle Adulticides on Grapes, 1985

Five insecticides were evaluated for efficacy against Japanese beetle adults in an experimental vineyard of Clinton grapes at Wooster, Ohio. Plots consisted of 1 grape vine, with 4 replications per treatment in a randomized block. Treatments were applied as foliar sprays on 13 Aug using a hand-held CO2 sprayer operating at 45 psi (3.2 kg/cm2) equipped with a 9505-E-TeeJet nozzle. The spreader, Ortho X-77, was used at the rate of 0.5 pint per 100 gal. On 2 and 9 days after application, 5 grape leaves were removed at random from the outside canopy of each treated plant for use in the bioassay. Leaves were brought into the laboratory where they were placed inside a ventilated 1 gal container with 25 Japanese beetles. The 1 gal ice cream cartons were modified by placing 16-mesh wire screen in the bottom and cheese cloth over the top. Each bioassay included 4 replicates. Mortality counts were made at given intervals after holding beetles on treated foliage for 24 h. The insect holding room was maintained at 75°F (23°C) with ca. 75% RH under a 16-h photoperiod.