Study On Resistance Mechanisms And Enzymology Resistance Monitoring Of Tetranychus Urticae Koch To Fenpropathrin

Tetranychus urticae Koch is one of important of worldwide pest mites,and caused seriously damage in many countries. In view of pesticide residues problem and food safety requirements, Pyrethroid pesticide were widly used to control for a long time, ( pyrethroids for short ). However, With higher frequency and large amount use the Tetranychus urticae have had resistance. Therefore, Overcoming on Tetranychus urticae resistant to pyrethroids, Extending use of pyrethroids and pyrethroid pesticide resistance management,It,s important to carry out Tetranychus urticae resistant on pyrethroid pesticide research and resistance monitoring techniques for overcoming . Study on resistance mechanisms and resistance monitoring of Tetranychus urticae Koch to fenpropathrin in the paper, The main results are the following:1.Using bioassay to test cross-resistance and resisance the of anti- fenpropathrin Tetranychus urticae Koch population fenpropathrin by indoor cultivation and Tetranychus urticae Koch(Tianshui-Resistance,Tsh-R and(Jingning-Resistance,Jn-R) Resistances collected from Tian-shui,Jing-ning to cross-resistance and resisance to 12 types insecticides.The results showed that:The thirty eight generation anti-fenpropathrin population,s Resistance indexs(RI) were 247.35 fold. and resistance indexs population had cross-resistance to five types Beta-cyfluthrin(RI19.53),Celastrusangulatus(RI19.02),Cypermethrin(RI12.13),Azocy-clotin(RI8.80) and Clofententezine(RI5.13),but no cross-resistance to six types insecticides of Propargite,Pyr-Clofentezine,Abamectin,pyridaben,Hydramethylnon and Dursban (RI<5.00).Tian-shui and Jing-ning resistant strains had high cross-resistance to insecticides of fenpropathrin(RI),The RI are103.76 and 92.3 respectively.Four types insecticides of propargite and Celastrusangulatus Beta-cyfluthrin were resistanted to some extent,RI was on between 5.04 and 29.76;but slight or no cross-resistance to seven types insecticidesof Clofentezine, Pyr-Clofentezine,Abamectin,Pyridaben,Hydramethylnon,Dursban,Azocyclotin(RI<5).2.Though the method of indoor bioassay and physiology and biochemistry,fenpropathrin resistant strains of Tetranychus urticae Koch for enzymological Monitor System were studied. The results showed that: Tetranchus urticae Koch resistant strains to fenpropathrin of the specific activities of Carboxylesterase(CarE),Acid Phosphatase,Alkaline Phosphatase,Mixed Function Oxidases (MFOs) and Glutathion (S-(transferase)) (GSTs) increased 1.84,13.95,3.76,4.262 and 17.386 times compared with the susceptible strain,respectively.After thirty-eight generations. Fe-R38 population michaelis constant (Km) but the maximal reaction velocity (Vmax) of carboxylesterase(CarE)were 0.243 and 1.879 times than that of the S,respectively.Tetranychus urticae Koch to Fe-R population of carboxylesterase Michaelis constant (Km) was decreased ,and the maximal reaction velocity (Vm) of enzyme was accelerated.Detoxifying enzymes activity of Tetranchus urticae resistant strains to fenpropathrin will increase with resistance ratios and selet generation, and exhibit a very strong proportional relation.Regression equation for obtaining resistance ratios, selecting generation and detoxifying enzymes activity of Tetranchus urticae resistant strains to fenpropathrin were studied.The specific activity of detoxifying enzymes to Tetranchus urticae resistant strains of Tianshui and Jingning were fit to regression equation respectively.It found that the two populations were highly resistant to pyrethroid pesticide,equivalent to the 22 generations and 20 generations of resistance level to fenpropathrin resistant strains. Monitoring results, Toxicity Indoor showed the same result. and can be used as enzymology of resistance monitoring method forTetranchus urticae Koch resistant strains to fenpropathrin.