螺虫乙酯对山楂叶螨种群的影响

Effects of spirotetramat on Tetranychus viennensis population

【目的】全面评价螺虫乙酯对山楂叶螨种群的影响。【方法】采用叶片浸渍法测定了螺虫乙酯对山楂叶螨成螨的致死效应,并通过时间-剂量-死亡率（TDM）模型进行了模拟。在此基础上,研究了螺虫乙酯对山楂叶螨雌成螨的亚致死效应。【结果】所建TDM模型通过Hosmer＆Lemeshow拟合异质性检验,螺虫乙酯对山楂叶螨致死率高峰出现在药后24 h,药后24 h、48 h、72 h的LC50值分别为294.58、254.70、172.61 mg·L^-1,浓度为200 mg·L^-1时LT50为62.63 h。药后9~10 d,螺虫乙酯200、20 mg·L^-1处理的山楂叶螨存活率降为20.00%和37.50%。山楂叶螨单雌产卵量、卵孵化率随螺虫乙酯浓度升高而急剧下降。与空白对照比较,螺虫乙酯200、20 mg·L^-1处理的山楂叶螨总繁殖力和净生育力分别降低44.11%、38.00%和82.79%、64.70%,螺虫乙酯0.02 mg·L^-1处理的总繁殖力和净生育力则分别提高1.73%和3.96%。螺虫乙酯各浓度处理对山楂叶螨F1代幼若螨存活率影响较小,与空白对照差异不显著。【结论】螺虫乙酯能够降低山楂叶螨种群数量。

【Objective】To evaluate the effects of spirotetramat on Tetranychus viennensis.【Methods】We in-vestigated the lethal effects of spirotetramat against the adult of Tetranychus viennensis using leaf-dip bio-assay method under laboratory condition. A time- dose mortality model（TDM） was established,whichpassed the Hosmer-Lemeshow test. On this basis,the sublethal effects of spirotetramat on female adult T.viennesis was investigated.【Results】The peak mortality of the female adults was found at 24 h after treat-ed with spirotetramat. The values of the LC50 at 24,48,72 h after treated with spirotetramat were 294.58,254.70,172.61 mg·L^-1,and the median lethal time（ LT50） of spirotetramat was 62.63 h at the concentra-tion of 200 mg·L- 1. The survival rates of the female adults treated by two sublethal concentrations（200mg·L^-1and 20 mg·L^-1） of spirotetramat fell to 20% and 37.5% at 9-10 d,respectively. The fecundity perfemale and the egg hatching rate declined sharply with the spirotetramat concentration increased. Com-pared with the control group,the gross fecundity and net fertility of female adult T. viennesis at the dose of200 and 20 mg·L^-1significantly reduced respectively 44.11%,38.00% and 82.79%,64.70% but the grossfecundity and net fertility increased respectively 1.73% and 3.96% at the dose of 0.02 mg·L^-1. The surviv-al rate of F1 generation was not significantly different with the control.【Conclusion】Spirotetramat can re-duce the population of Tetranychus viennensis.