Abstract Lettuce was direct seeded into double-rows on 42-in beds on 9 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 gpa at 200 psi. All treatment applications included Crocker’s Fish Oil at 10 oz/acre and Kinetic non-ionic surfactant at 0.10% v/v. Treatments were split into two regimes (early-season and late-season). The early-season applications were applied on 1 Oct, 11 Oct and 17 Oct. The late-season applications were applied on 25 Oct, 31 Oct, 5 Nov and 18 Nov. Evaluations were made five to six days after each application (7 Oct, 16 Oct, 22 Oct, 30 Oct, 4 Nov, 12 Nov and 25 Nov) by randomly selecting 10 plants per plot and counting the number of live small (1st and 2nd instar) and large (>2nd instar) CL larvae. Data were analyzed for treatment differences using ANOVA and an F protected LSD.