Toxicity and the effects of four pyrethroid insceticides on the activity of ATPase and GSTs in Aphis sp.

In order to find out pesticide that can control Aphis sp. effectively, residual film method was used to determine the toxicity of four pyrethroid insecticides, and the effects of four insecticides on ATPase and glutathione S-transferases (GSTs) in Aphis sp. were investigated. The results indicated that Aphis sp. showed the highest sensitivity to bifenthrin, with LC50value of 4.34 mg/L, while the LC50 values of permethrin, beta-cypermethrin and fenpropathrin were 17.08 mg/L, 40.50 mg/L and 184.84 mg/L, respectively. The activity of two kinds of ATPase in Aphis sp. could be significantly inhibited by the four insecticides. When the concentration of the four pyrethroid insecticides was 1×10-4 mol/L, the inhibition to Na+-K+-ATPase was higher than that to Ca2+-Mg2+-ATPase; The order of inhibition to Na+-K+-ATPase was bifenthrin > beta-cypermethrin > permethrin > fenpropathrin; While to Ca2+-Mg2+-ATPase, the inhibition of bifenthrin was the highest, with inhibition rate of 46.41%, and the inhibition of beta-cypermethrin was the lowest, with inhibition rate of 33.04%. The effects of four pyrehtroids on glutathione S-transferases (GSTs) in Aphis sp. varied. Bifenthrin could induce the GSTs activity at low concentration, but inhibited significantly at high concentration; Both beta-cypermethrin and permethrin inhibited the activity of GSTs, and the maximum inhibition rate was 85.02%; Meanwhile, the activity of GSTs increased by 193.07%-249.96% after Aphis sp.was treated with fenpropathrin.