Control of soldier fly with controlled-release insecticides : final report CO95011

Abstract

The activity of controlled-release granules against soldier fly larvae was evaluated in laboratory bioassays. Five different active ingredients were tested in a range of granule sizes. The product selected as the most effective varied depending on the time which had elapsed after mixing with the soil. For most compounds, smaller granules were more active in the short term but lost activity more rapidly than the larger granules. Rates of loss of activity during incubation varied between active ingredients. Granules containing carbofuran and carbosulfan showed increased activity during the first year. The most active products in soil after 0, 1 and 2 years were phorate 2 mm granules, carbofuran 1 mm granules, carbofuran 1.5 mm granules and tefluthrin 1 mm granules, respectively.

Nine field trials using 2 mm chlorpyrifos granules (14%, suSCon Blue), 1 mm chlorpyrifos granules (10%, suSCon Green) or 1.5 mm phorate granules (10%, suSCon FuMing) were sampled for soldier fly. Results show that chlorpyrifos granules will not control soldier fly. Any efficacy of granules containing phorate was short-lived and not detected in larval numbers > 1 year after application. No residues were detected in cane juice 5-8 months after phorate granules were applied at 4 kg ai ha -1.