亚致死浓度吡虫啉对麦二叉蚜多个世代生命表的影响

【目的】探究不同吡虫啉亚致死浓度处理麦二叉蚜Schizaphis graminum（Rondani）]后对其试验种群亲代及连续2个子代世代的影响，以揭示麦二叉蚜多个世代对吡虫啉亚致死浓度的响应，为田间合理用药提供理论依据。【方法】采用不同亚致死浓度（LC₂₀和LC₄₀）吡虫啉处理当代麦二叉蚜后，利用生命表技术分析经吡虫啉亚致死浓度胁迫后麦二叉蚜亲代（F₀）及连续2个子代世代（F₁和F₂）存活及生命表参数的变化。【结果】不同亚致死浓度吡虫啉对麦二叉蚜的存活和发育影响不同，与对照相比，LC₂₀浓度吡虫啉对麦二叉蚜亲代种群及子代种群的存活率和寿命均无显著影响（P>0.05，下同）；LC₄₀浓度吡虫啉显著降低亲代麦二叉蚜种群的中位生存期（P<0.05，下同），为对照的71.55%，但对2个子代种群的中位生存期无显著影响；不同世代间，LC₄₀浓度处理的存活率和寿命随世代数的增加而增加。与对照相比，LC₂₀浓度吡虫啉对麦二叉蚜亲代及2个子代种群的繁殖均无显著影响；LC₄₀浓度吡虫啉可显著抑制麦二叉蚜亲代种群的繁殖，但对F₁及F₂世代种群的繁殖无显著影响。生命表分析结果表明，与对照相比，2个亚致死浓度吡虫啉对麦二叉蚜同一子代世代的种群生命表参数均无显著影响；同一亚致死浓度吡虫啉对2个子代世代的种群生命表参数也无显著影响。【结论】不同亚致死浓度（LC₂₀和LC₄₀）吡虫啉对亲代麦二叉蚜的生存率、寿命和繁殖率存在显著影响，且呈明显的剂量效应，但对2个子代种群的生命表参数均无显著影响。

Effects of sublethal concentrations of imidacloprid on the transgenerational life table characteristics of Schizaphis graminum (Rondani)

【Objective】 The effects of the imidacloprid on the parental generation and two successive filial progeny of the Schizaphis graminum(Rondani)were assessed. It was beneficial for revealing the response of an experimental population of S. graminum to sublethal concentrations of imidacloprid through multiple generations,which could provide a theoretical basis for the reasonable usage of insecticides in the field.【Method】 The life table and survival characteristics of S.graminum in the parental generation(F₀)and two successive filial progeny(F₁ and F₂)were detected after the parental individuals have been exposed to different sublethal concentrations of imidacloprid(LC₂₀ and LC₄₀).【Result】 Different concentrations of imidacloprid exerted different influences on the survival rate and growth of S. graminum. The LC₂₀ concentration of imidacloprid had no significant effect on the survival rate and median survival time of the parental and successive two filial generations of S. graminum populations(P>0.05,the same below). However,the LC₄₀ concentration of imidacloprid in the F₀ generation significantly reduced the survival rate of aphids(P<0.05,the same below),and median survival time of the LC₄₀ group was only 71.55% compared with the control aphids. However,there was no significant effect on the median survival of the two offspring populations. The survival rate and longevity of the LC₄₀ group increased with numbers of generations in three successive generations. The LC₂₀ concentration of imidacloprid had no significant effect on the fecundity of the parental and successive two filial generations of S. graminum populations compared with control.Moreover,the LC₄₀ concentration of imidacloprid significantly reduced the fecundity of aphids in the F₀ generation,while without a significant effect on the fecundity of S. graminum populations in the F₁ and F₂ generations. In addition,within generations,the values of life table characteristics of S. graminum in the LC₂₀ or LC₄₀ group were no significantly different compared with those of the control of both two successive filial generations. Moreover,the values of life table characteristics of aphids to the same sublethal concentrations of imidacloprid(the LC₂₀ or LC₄₀ group)were not significantly different between their two successive filial progeny.【Conclusion】 The results suggests that the survival rates,life span,and fecundity of parental aphids are significantly different from groups(LC₂₀ and LC₄₀)exposed the two sublethal concentrations of imidacloprid with obvious dose effect,while this effect on life table characteristics of S. graminum in two treated groups is not significantly different in the two successive filial generations.