Control of Agrotis ipsilon in seedlings of transgenic Bt maize after treatment of seeds with different products

In an attempt to improve effectiveness control of Agrotis ípsilon caterpillar (Hufnagel) (Lepidoptera: Noctuidae) in transgenic Bt maize, we tested these associated with the treatment of seeds in the field. The trial was conducted in Ribeirão Preto, Brazil, with sowing on 12/16/2013. The experimental plots (blocks in a 3x4 factorial design with 4 replications) were a line of 2 m with 5 plants (seedling) per meter. The treatments were the combination of non-transgenic and transgenic corn expressing the proteins Cry1F PAT (2B707, Herculex®) and Cry1A.105 Cry2Ab2 Cry1F PAT EPSPS (2B707, Powercore®) with seed treatment with imidacloprid + thiodicarb (CropStar®), thiamethoxam (Cruiser® 700 WS), thiamethoxam + abamectin (Avicta® 500 FS) and one without treatment. Two days after germination (12/23/2013), the seedlings of each plot were involved with barriers and infested with one 4th instar of A. ípsilon caterpillar per seedling. After 1 (24/12/2013), 3, 10 and 15 days of infestation, the plants were evaluated for percent defoliation and cut seedlings. Seed treatment did not improve the efficacy of transgenic Bt maize in control of A. ipsilon in seedlings, but the use of thiamethoxam + abamectin was efficient to control caterpillars in non-trangenic maize. The control of A. ípsilon caterpillars was effective in transgenic Bt maize treatments.