Safety Evaluation and Toxicity Determination of 5 Biopesticides to Myzus persicae (Sulzer) and Aphidoletes aphidimyza(Rondani)

To screen for biopesticides safe to Aphidoletes aphidimyza (Rondani) in tobacco fields, the toxicities of five kinds of biopesticides against Myzus persicae, as well as three instars larvae (spray method) and adults of A. aphidimyza were evaluated. The results showed that the highest toxicity on M. persicae was from emamectin benzoate and matrine both at 24 h and 48 h after treatment, with LC₅₀ 2.166 and 3.695 mg/L (24 h), 1.567 and 2.874 mg/L (48 h), respectively. The highest toxicity on larva of A. aphidimyza was from rotenone, with LC₅₀ 18.137 mg/L (24 h) and 13.771 mg/L (48 h). The highest toxicity on adults of A. aphidimyza was from spinosad, with LC₅₀ 7.249 mg/L (24 h) and 4.125 mg/L (48 h). Therefore, matrine, emamectin benzoate and Bacillus thuringgiensis in the five biological pesticides have higher selectivity to M. persicae and A. aphidimyza, so they are suitable for the combined application of biopesticides and A. aphidimyza in the field to control M. persicae.