EVALUATION OF SELECTED INSECTICIDES AGAINST FALL ARMYWORM IN A LAB-FIELD TEST, 2005

The efficacy of selected insecticide treatments was evaluated against fall armyworm at the Macon Ridge Research Station near Winnsboro, LA. The soil type for this trial consisted of a Gigger-Gilbert silt loam soil with a pH = 6.1 and 1.1% organic matter. Cotton was planted on 5 May into plots that were four rows centered on 40-inches and 50 feet in length. Treatments were arranged in a RCB design with three replications. On 25 Jul, treatments were applied using a compressed air system calibrated to deliver 10 gpa through Teejet 80015 flat fan nozzles (2/row) at 30 psi. One hour following insecticide application, three first position squares from the upper third of a plant were harvested and placed in a plastic Petri dish. In addition, one first position and quarter-sized boll from the mid-canopy of a plant was placed in a 1 oz plastic cup. For both tissues harvested, 10 plants were sampled in each plot. Each plastic dish was infested with five 2-d-old larvae and 1oz cups were infested with one 5-d-old larva. Mortality was determined at 72 and 96 h after infestation (HAI). Data were analyzed using ANOVA and means were separated according to DMRT. No rainfall occurred during the test.