IMIDACLOPRID FORMULATIONS FOR THE PREVENTIVE CONTROL OF JAPANESE BEETLE LARVAE IN TURFGRASS, 2008

Abstract

This study was conducted to evaluate different formulations of imidacloprid for the preventive control of JB larvae in turfgrass. Testing was done in a turf plot maintained at the NYS Agricultural Experiment Station (Geneva, NY). The site had been renovated and reseeded to perennial ryegrass in May, and maintained at a mowing ht of 3.5-4 inches. Evaluation units were PVC arenas (diameter 12 inches, depth 4 inches) placed in the ground so that the upper lip was level with the soil surface. Arenas were arranged in a RCB design with eight repetitions of four treatments. Infestations were made on 25 Jul 2008 by enclosing 15 male and 15 female JB adults over each ring for seven days of mating and oviposition. Treatment applications were made 1 Aug 2008. Liquid formulations were applied with a pressurized CO2 sprayer coupled with a single nozzle spray wand and a Teejet 8002VS flat fan tip. Granular formulations were evenly applied using a shaker jar. Conditions at time of application were the following: skies partly sunny; wind negligible; air temp 73.0°F; soil temp at 2inch depth 80.5°F. Until the study was rated, rainfall was supplemented with 0.25 inch irrigation if five consecutive days lapsed with <0.10 inches rain on any of those days. Mean daily precipitation was 0.13 inch; mean daily air temp (min/max) 57.0/73.5°F; and mean daily soil temp at 2.0-inch depth (min/max) 65.0/82.5°F. JB larval populations were evaluated on 5 Sep 2008 by destructively searching the soil in each arena. Data were transformed by sqrt(x+0.5) before ANOVA, followed by LSMeans separation using Student’s t.