Field and Bioassay Evaluations, 1988

Abstract

Abstract Four insecticides were evaluated for efficacy against the adult Japanese beetle, tarnished plant bug, meadow spittlebug, and strawberry sap beetle. A 10-yr-old experimental raspberry planting at Wooster, Ohio, was used for this study. Replicates consisted of 18-ft2 areas, with 4 replicates/treatment in a randomized complete block design. Treatments were applied as foliar sprays at a rate of 100 gal/acre (935 liter/ha) on 5 Jul and 26 Jul, using a hand-held CO2 sprayer operating at 45 psi (3.2 kg/cm2) and equipped with a 9505-E-TeeJet nozzle. For the field evaluation readings of the number of live Japanese beetles in each plot were taken immediately before insecticides were applied; at 4 h after treatment; and at 2, 3, and 6 DAT. The bioassay evaluation began 26 Jul, after the insecticides had dried on foliage. Five leaves were sampled from each replicate and placed in 1-gal round ice cream containers. In the bioassay, 10 adult tarnished plant bugs, 10 meadow spittlebugs, and 10 strawberrry sap beetles were added to each container. The number of dead insects was recorded 24 h after exposure to the treated foliage. At 3 DAT a Japanese beetle bioassay of treated foliage was begun and the number of dead insects was recorded 24 h after exposure.