Control of Russian Wheat Aphid (RWA) in Winter Wheat, 1989:

Seventeen insecticides in a total of 26 combinations were evaluated for performance in controlling RWA in a lightly infested field near Connell, Franklin County, WA. Treatments were applied with a CO2-powered backpack sprayer with a 9 ft boom calibrated to deliver 20 gal/acre at 30 psi. The insecticides were applied on 19 Oct (treatments 1-12) and 20 Oct (treatments 13-28) because wind increased to > 5 mph before spraying could be completed. Plots were 18 x 18 ft, replicated 4 times, and arranged in a completely RCB design. The plots were located within a block of wheat seeded on 27 Aug (seeding rate: 42 lb/acre, 18 inch row spacings). Pretreatment wheat seedlings averaged 3 tillers and main stems. Treatments were evaluated at 7 and 14 DAT. Approximately 7 plants with symptomatic tillers were taken from each plot, placed into paper bags and held in a cooler until they were placed in Berlese-Tulgren funnels later in the day. After extraction, the number of plants and tillers for each sample was recorded; aphid densities for this evaluation are expressed as number of aphids per tiller. RWA comprised 96% of the aphid species while the remaining 4% were bird cherry-oat aphids. Results were thus analyzed on the basis of the total number of aphids extracted per treatment.