Sensitivity of Nerve Na-K-ATPase, Ca-ATPase and Ca-Mg-ATPase in Resistant Strains of Spodoptera exigua to lambda-Cyhalothrin

The activity of Na-K-ATPase, Ca-ATPase and Ca-Mg-ATPase in susceptible and lambda-cyhalothrin resistant strains of beet armyworm, Spodoptera exigua, were determined. The results indicated that there was no significant difference in Na-K-ATPase activity between the two strains, but the activity of Ca-ATPase and Ca-Mg-ATPase were much lower in resistant strain than in susceptible strain. Lambda-cyhalothrin at concentrations of 1.0×10-8~1.0×10-3 mol/L inhibited obviously the three mentioned above ATPase activities in two strains, and the inhibition was higher in susceptible strain than in resistant strain. For example, at concentration of 1.0×10-4 mol/L, the inhibition on Na-K-ATPase, Ca-ATPase and Ca-Mg-ATPase activities was 29.6%, 34.3% and 22.3% in susceptible strain and 21.8%, 21.9% and 16.9% in resistant strain,respectively. The results showed that the sensitivity of these three ATPases to lambda-cyhalothrin in resistant strain were decreased.