ABSTRACT

Various insecticides at different rates were used in Lincoln County Arkansas in 2003 to determine the efficacy of those insecticides for controlling the cotton aphid, Aphis gossypii (Glover), population. The control methods for this study consisted of a single spray application of selected rates for cyfluthrin (Baythroid^® 2 EC), acetamiprid (Intruder^® 70 WP), thiamethoxam (Centric^® 40 WG), imidacloprid (Trimax^® 4 SL), and bifenthrin (Capture^® 2 EC). This spray application was applied on June 24, 2003 with a two man CO₂-pressurized hand boom at a rate of 10.17 gallons per acre (GPA). One whole plot consisted of 14.25 feet by 50 feet of Deltapine 451^®. Two subsequent evaluations were conducted at 2 and 5 days after treatment (DAT). These evaluations were conducted on a five leaf per plot basis, with each leaf selected at random from the tops of the plants. A one inch square area at the leaf / petiole junction was visually evaluated to provide a uniform evaluation method for determining the aphid population numbers. An average across the two evaluation dates indicates that acetamiprid (0.03570 lbs. ai / A) had the highest control rate at 99.0 % of the untreated check. On the same average, bifenthrin (0.06 lbs. ai / A) had the lowest rate of control at 19.4 % of the untreated check. At 5 DAT the aphid population in the bifenthrin (0.06 lbs. ai / A) treated area was higher than the aphid population in the untreated check.