Analysis Of Toxicology Mechanisms And Monitor Of Resistance In Myzus Persicae On Potato

Myzus persicae is a global pest of agriculture. The susceptibility of field samples of Myzus persicae to 13 kinds of commonly used insecticides in Hohhot and Wuchuan area was examined. We carried out the study of biochemical mechanisms for carboxylesterase (CarE) and acetylcholin esterase (AchE) in potato aphids. The major results as follows:1. The study shows that the toxicity of fenvalerate, cyhalothrin and bifenthrin had the higher in the seven pyrethroids insecticides to M. persicae on potato of Wuchuan and Hohhot stains, The M. persicae from Hohhot had the lowest susceptibility to deltamethrin, and the value of LC50 was 2397.28mg/L. The M. persicae from Wuchuan had the lowest susceptibility to cypermefhrin, and the value of LC50 was 16904.35 mg/L.2. Results shows that the toxicity of triazophos had the higher than omethoate to M. persicae on potato of Hohhot and Wuchuan stains. The LC50 were 62.72 mg/L and 177.85mg/L, respectively. M. persicae on potato of Hohhot and Wuchuan stains had higher susceptibility to methomyl, the LC50 were 139.36mg/L and 248.17 mg/L, respectively3. The toxicities of imidacloprid to M. persicae on potato from Hohhot was higher than that Wuchuan, and the value of LC50 were 40.708mg/L and 118.63mg/L, respectively. M. persicae on potato of Hohhot and Wuchuan stains had the lower susceptibility to avermectins4. The activity of acetyl cholinesterase (AChE) order of M. persicae on potato of different districts was Wuchuan strain> Hohhot strain> Beijing strain. The value of activity were 0.35、0.27、0.25μmol.min-1.mg.protein-1, respectively. The activity of AChE of Three strains were significantly inhibited by triazophos. isoprocarb showed the lowest inhibiting rates to acetylcholine esterase of three strains Myzus persicae.5. There was a significant positive correlation between the carboxylesterase activity and resistance ration to pyrethroids. Carboxylesterase activity of Wuchuan and Beijng strain were significantly inhibited by triazophos, IC50 was 0.54nmol/L and 0.93nmol/L respectively. Carboxylesterase activity of Hohhot strain was maximum inhibited by isoprocarb, IC50 was 0.42nmol/L. triazophos and isoprocarb will be compounded with pyrethroids respectively, have the potential to control Myzus persicae in Wuchuan and Huhhot than those of single.