Bioassay and Avoidance (Repellency) Evaluation of Japanese Beetle Adulticides on Grapes, 1986

Abstract

Abstract Four insecticides were evaluated for efficacy against Japanese beetle adults in an experimental vineyard of Clinton grapes at Wooster, Ohio. Plots consisted of one grape vine, with 4 replications per treatment in a randomized block design. Treatments were applied as foliar sprays at rate of 100 gal/acre (379 1/ha) on 21 Jul using a hand-held CO2 sprayer at 45 psi (3.2 kg/cm2) with a 9505-E-TeeJet nozzle. After treated foliage was dry, 5 grape leaves were removed at random from the outside canopy of each treated plant. Leaves were brought into the laboratory and placed in a ventilated 1-gal ice cream container with 10 Japanese beetles. The containers were modified by placing plastic liners inside and cheese cloth over the top. A mortality count was made after holding beetles on treated foliage for 24 h. The insect holding room was maintained at 75°F (23°C) with ca. 75% RH. In addition to the bioassay, a reading of the number of live Japanese beetles present in the field plots was taken 24 h after initial application of the insecticides. The number of live beetles present on the grape foliage of each plot were counted. All treatments in the bioassay were statistically better than the check in both the lab and the field. None of the treatments was phytotoxic to the grape foliage.