Efficacy and Effects of Guthion and Pydrin Applied from Aircraft on Selected Non-Target Arthropod Predators for Sugar-Casle Borer Control, 1979

Abstract

Abstract Guthion and Pydrin applications for full-season sugarcane borer (SCB) control were applied to sugarcane (plant cane crop, Cultivar CP 65-357) in a large-plot field trial located on Little Texas Plantation near Napoleonville, LA. A randomized complete block experimental design with treatments replicated 6 times was employed. Individual plots ranged in size from 2.8 to 3.2 acres. Treatments consisted of an untreated control, guthion applied at 0.75 lb ai/acre and Pydrin applied at 0.10 or 0.20 lb ai/acre. All insecticide concentrates were applied in water to the plant canopy at a rate of 2 gal finished formulation/a per application. Insecticide applications were initiated after sugarcane inter nodes were first visible above ground and when 5% of the stalks (x per plot) harbored small (lst-to 3rd-stage) SCB larvae in leafsheaths. Applications were repeated only when that level of infestation was found again in guthion-treated plots. All insecticide treatments ceased in early fall when SCB infestations no longer posed a threat to the sugarcane crop. Two applications of each insecticide formulation were made one month apart (August 22, September 21). Ongoing populations of non-target (ground associated) arthropods were sampled by placing two pitfall traps 150 ft apart on the center row of each plot. Each trap consisted of a 1-pt jelly jar imbedded in the soil at ground level and partially filled with a solution composed of 3 pt erhanol plus 1 pt mineral oil. A 9 in dia metal disk on a tripod was placed 1 in above ground level over each trap to exclude rain and debris. Accumulated trapped arthropods were removed biweekly from July 7 to October 5. Residual efficacy of insecticide treatments was determined at crop harvest time (October 9) by examining 100 stalks randomly selected from each treated or untreated plot for the presence of SCB-bored inter nodes.