ABSTRACT
Objective To detect the resistance index and esterase activity of each generation of DDVP-resistant Culex mosquitoes and analyze the relationship between insecticide resistance and esterase. Methods WHO bioassay and micro-plate measurement were used for the detection. Results The resistance index increased to 12.17 after 43 generations' insecticide selection compared to 1.00 as sensitive isolate. The nonspecific esterase(NSE) activity of the mosquitoes became strengthened with the extension of the generations, and the individual frequency of those with OD values no less than 0.9 increased gradually, consistent basically to the bioassay. The AChE average inhibition rate decreased with the extended generation and increased resistance, and the individual frequency of those with inhibition rate less than 30% became strengthened with the extension of generations, showing a positive correlation. Conclusion The activity of NSE and AChE shows a correlation with DDVP resistance.