Abstract The plant mirid bugs, Lygus pratensis Linnaeus and Polymerus cognatus Fieber, are key pests on economically important cotton crops and ecologically important grassland in northwestern China. Lambda-cyhalothrin is frequently used against mirid bugs in the regions. In this study, we examined the sublethal and transgenerational effects of short-term exposure to lambda-cyhalothrin on biological traits using a miminal dose, LD5 [0.484 ng/L. pratensis adult, and 0.171 ng/P. cognatus adult], a low lethal dose, LD25 [1.353 ng/L. pratensis adult, and 0.781 ng/P. cognatus adult] and a moderate lethal dose, LD50 [2.766 ng/L. pratensis adult, and 2.243 ng/P. cognatus adult]. Direct exposure to LD50 of lambda-cyhalothrin led to decreased adult longevity, shorter female oviposition period and lower fecundity of the parental generation for both species, whereas treatment with LD5 lambda-cyhalothrin stimulated female fecundity on L. pratensis, but not on P. cognatus. The F1 generation underwent transgenerational effects, i.e. there was delayed egg-laying period and larval development and decreased hatchability for both species, decreased adult longevity and fecundity for L. pratensis, and shortened adult longevity for the LD50 group of P. cognatus. Compared with the untreated control group, the net reproductive rate (R0), the intrinsic rate of increase (rm), and finite rate of increase (λ) were significantly decreased for the groups treated with different doses of lambda-cyhalothrin, whereas the generation time (T) was increased. Our results demonstrate that sublethal effects of lambda-cyhalothrin can retard development and suppress population growth for both of these mirid species. Therefore, this insecticide can be used effectively against mirid bugs in northern China and its application strategy to control mirid bug is discussed.

中文翻译：

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λ-三氯氟氰菊酯对紫螟Lygus pratensis Linnaeus 和Polymerus cognatus Fieber 的亚致死和跨代效应

摘要 植物绦虫Lygus pratensis Linnaeus 和Polymerus cognatus Fieber 是我国西北部重要经济作物和重要生态草原的重要害虫。Lambda-三氯氟氰菊酯经常被用来对付这些地区的昆虫。在本研究中，我们使用最小剂量 LD5 [0.484 ng/L. pratensis 成虫，和 0.171 ng/P。cognatus 成人]，低致死剂量，LD25 [1.353 ng/L。pratensis 成虫，和 0.781 ng/P。cognatus 成人]和中等致死剂量，LD50 [2.766 ng/L。pratensis 成虫，和 2.243 ng/P。同源成人]。直接暴露于 λ-三氯氟氰菊酯的 LD50 导致两个物种的成虫寿命缩短、雌性产卵期缩短和亲代繁殖力降低，而用 LD5 λ-三氯氟氰菊酯处理会刺激 L. pratensis 的雌性繁殖力，但不会刺激 P. cognatus。F1代经历了跨代效应，即两个物种的产卵期和幼虫发育延迟，孵化率下降，成虫寿命和繁殖力降低，白尾鲟LD50组成虫寿命缩短。与未处理对照组相比，不同剂量λ-三氯氟氰菊酯处理组的净繁殖率（R0）、内在增长率（rm）和有限增长率（λ）均显着降低，而代时间（T）增加。我们的研究结果表明，λ-三氯氟氰菊酯的亚致死作用可以延缓这两个类的发育并抑制种群增长。所以，