唑虫酰胺对甜菜夜蛾亚致死效应及解毒酶活性的影响

为明确唑虫酰胺对甜菜夜蛾的亚致死效应以及甜菜夜蛾对唑虫酰胺的生化抗性机制, 本研究在测定10种药剂对甜菜夜蛾室内毒力的基础上, 研究了唑虫酰胺LC10、LC30和LC50浓度对甜菜夜蛾生长繁殖和解毒酶活性的影响及甜菜夜蛾的生化抗性机制。结果表明, 高浓度处理组(LC50)的甜菜夜蛾成虫寿命、羽化率和卵孵化率等均显著低于对照组, 低浓度唑虫酰胺(LC10)诱导了甜菜夜蛾谷胱甘肽 S-转移酶(GST)和羧酸酯酶(CarE)活性的上升, 显著抑制了多功能氧化酶(MFO)的活性;增效试验表明, 增效醚(PBO)和磷酸三苯酯(TPP)对唑虫酰胺有明显的增效作用。抗性种群的CarE、MFO和GST酶活都显著高于敏感种群。综上, 低浓度的唑虫酰胺对甜菜夜蛾的生长发育有显著的抑制作用, MFO、CarE和GST在甜菜夜蛾对唑虫酰胺的抗性中发挥了重要作用。

Sublethal effects of tolfenpyrad and its impact on detoxifying enzymes to Spodoptera exigua

To clarify the sublethal effects of tolfenpyrad to Spodoptera exigua and biochemical resistance mechanism of S.exigua to tolfenpyrad, the indoor toxicity of 10 different pesticides against S.exigua were measured and the impacts of tolfenpyrad at LC10, LC30, and LC50 concentrations on the growth, reproduction, detoxifying enzyme activity were assessed, and biochemical resistance mechanism of the S.exigua to tolfenpyrad was explored. The results indicated that the adult lifespan, emergence rate, and egg hatching rate of S.exigua in high concentration treatment group (LC50)were significantly lower than those in the control group. Low concentration of tolfenpyrad (LC10) induced an increase in the activity of glutathione S-transferase (GST) and carboxylesterase (CarE) in S.exigua, while significantly inhibiting the activity of multifunctional oxidase (MFO). Synergism tests showed that piperonyl butoxide (PBO) and triphenyl phosphate (TPP) exhibited noticeable synergistic effects on tolfenpyrad. The enzyme activities of CarE, MFO, and GST in the resistant population were significantly higher than those in the susceptible population. In summary, low concentrations of tolfenpyrad exert a significant inhibitory effect on the growth and development of S.exigua, with MFO, CarE and GST playing crucial roles in its resistance to tolfenpyrad.