六种农药对两种果蝇成虫室内毒力和主要解毒酶活性的影响

为明确田间常用农药对伊米果蝇Drosophila immigrans和海德氏果蝇D. hydei的毒力和解毒机制,采用药膜法在室内测定6种田间常用农药原药对2种果蝇实验种群成虫的LC_(10)、LC_(20)和LC_(50),并研究其中3种农药的亚致死剂量(LC_(10)、LC_(20))对果蝇谷胱甘肽S-转移酶(GST)、羧酸酯酶(CarE)、乙酰胆碱酯酶(AchE)3种主要解毒酶活性的影响。结果表明,乙基多杀菌素对伊米果蝇的毒力最大,LC_(10)、LC_(20)和LC_(50)分别为0.29、0.51和1.51 mg/L;甲维盐对海德氏果蝇的毒力最大,LC_(10)、LC_(20)和LC_(50)分别为0.14、0.36和2.09 mg/L;吡虫啉对2种果蝇的毒力均最低。不同亚致死浓度的乙基多杀菌素处理伊米果蝇24 h后,CarE和AchE活性均显著高于对照,而GST活性在低浓度时显著高于对照;高浓度甲维盐仅对海德氏果蝇AchE活性有显著抑制作用;吡虫啉可抑制伊米果蝇AchE和海德氏果蝇CarE活性。表明伊米果蝇和海德氏果蝇可通过改变3种解毒酶的活性来防御杀虫剂对其造成的影响。

Toxicities of six pesticides and their effects on detoxification enzymes in the adults of two Drosophila species in the laboratory

To clarify the toxicity of six kinds of pesticides on Drosophila immigrans and D. hydei, the median lethal concentrations (LC₁₀, LC₂₀, LC₅₀) against Drosophila adults treated with pesticides were studied with residual film method. The effects on the activities of the three main detoxification enzymes (GST, CarE and AchE) were explored by three pesticides with the sublethal dose (LC₁₀, LC₂₀). The results showed that the toxicity of spinetoram was highest to D. immigrans among all pesticide treatments, and the values of LC₁₀, LC₂₀ and LC₅₀ were 0.29, 0.51 and 1.51 mg/L, respectively. The toxicity of emamectin benzoate was the highest to D. hydei, and the values of LC₁₀, LC₂₀ and LC₅₀ were 0.14, 0.36 and 2.09 mg/L, respectively. The imidacloprid had the lowest toxicity to D. immigrans and D. hydei. The activities of CarE and AchE of D. immigrans and D. hydei treated by spinetoram for 24 hours were significantly higher than that of the control, while the activity of GST was significantly higher than that of the control only at lower concentrations. The activity of AchE was inhibited at high concentration of emamectin benzoate in D. hydei; the activities of AchE in D. immigrans and CarE in D. hydei were both inhibited at sublethal concentrations of imidacloprid. The results indicated that D. immigrans and D. hydei could defense the pesticides through changing the activities of detoxification enzymes.