Abstract Lettuce was direct seeded into double-rows on 40-in beds on 6 Sep at the Yuma Valley Agricultural Center, Yuma, AZ. Plots were four beds wide by 30 ft long. Each plot was bordered on each side by two blank beds. Plots were arranged in a RCB design with four replicates. Treatments were applied using a tractor-mounted sprayer with three TX-6 hollow cone nozzles per bed, calibrated to deliver 40 gal/acre at 200 psi. All treatment applications included Kinetic spreader-sticker at 0.05% v/v. Treatments were applied on 21 Sep, 28 Sep, 6 Oct, 14 Oct, 19 Oct and 26 Oct. Evaluations were made five days after each treatment (26 Sep, 3 Oct, 11 Oct, 19 Oct, 24 Oct and 31 Oct) by randomly selecting 25 plants per plot and counting the number of live small (1st and 2nd instar) and large (>2nd instar) BAW and CL larvae. Data were analyzed for treatment differences using ANOVA and an F protected LSD.