Residual Effect of the Insecticides Flonicamid and Spiromesifen against Aphis craccivora (Hemiptera: Aphididae) and Persistence Dynamics in Faba Bean1

Field efficacy trials determined that flonicamid was more effective than spiromesifen and the negative control compound acetamiprid against Aphis craccivora Koch on faba bean, Vicia faba L. Flonicamid and spiromesifen residues in bean tissue and in soil were determined with high-performance liquid chromatography and gas chromatography-mass spectrometry. Using a spike level of 0.1–1 mg/kg, the recovery of flonicamid from bean tissue was 89.2% and from soil 81.4%. Spiromesifen recovery was 99.4% from bean and 90.3% from soil. The relative standard deviations ranged from 2.54 to 8.14%. According to the dissipation kinetics, the half-life of flonicamid residue in beans was 1.93 d and 1.96 d in soil, while that of spiromesifen in beans was 2.35 d and in 2.59 d in soil.