Effects Of Insecticides And Enzyme Inhibitors On Three Ladybird Species And Lipaphis Erysimi Kaltenbach And Toxicological Mechanism

The susceptibility to insecticides in the Propylaea japonica (Thunberg), Chilomenes quadriplagiata (Swartz) and Verania discolor (Fabricius), collected from the vegetable districts of Nongda and Shangjie, Fuzhou, were detected using residual film. The results showed the order of the susceptibility to insecticides was, emamactin benzoate> avermectins, imidacloprid> spinosads> dichlorvos> fenvalerate> methamidophos in P. japonica, dichlorvos> emamactin benzoate, methamidophos, avermectins > imidacloprid, fenvalerate> spinosads> fipronil in C. quqdriplagiata, and emamactin benzoate > avermectins >cypermethrin > imidacloprid> dichlorvos >fenvalerate, fipronil > chlorpyrifos > methamidophos in V. discolor. Besides, the susceptibility to insecticides in the field populations of Lipaphis erysimi Kaltenbach that collected from the vegetable districts of Nongda and Shangjie, Fuzhou, were detected using leaf-dip bioassays. The order of the susceptibility to insecticides was, emamactin benzoate > avermectins > spinosads > Imidacloprid > fipronil > fenvalerate > methamidophos. Avermectins, fipronil, spinosads and imidacloprid showed high selective coefficients between three ladybird species and L. erysimi.Three enzyme inhibitors, piperonyl(PB), triphenyl phosphate (TPP) and diethyl maleate (DEM), were used to analyzing the synergistic effects on methamidophos , fenvalerate and avermectins In P. japonica and L. erysimi. The synergisms on the three insecticides by PB were significantly higher than those by TPP and DEM in two insect species.Based on the inhibitions of the three synergists on the enzyme activities, in vivo, significant inhibitions of glutathione-S-transferase (GSTs), carboxylesterase (CarE) and acetylcholinesterase (AChE) activity by PB, CarE activity by and TPP, and GST activity by DEM were found in In P. japonica and C. quadriplagiata. In some time, the AChE activity by TPP and DEM were found in In P. japonica and...