Bacillus thuringiensis Berliner subsp. kurstaki (Btk) and Habrobracon hebetor Say are both biological control agents of Helicoverpa armigera Hubner. The present study evaluated their compatibility for combined application against this pest by examining the acceptability of Btk-inoculated hosts for H. hebetor females and testing for negative life-history impacts on developing progeny. Second-instar H. armigera larvae fed for 72 h on potted chickpea plants treated with three concentrations of Btk (LC₁₅, LC₃₅, and LC₇₀) and were then used in bioassays of parasitoid development and parasitism behavior. Survival of parasitoids was significantly reduced, and immature development prolonged, on hosts fed chickpea plants treated with LC₃₅ and LC₇₀ Btk, but not on plants treated with LC₁₅ Btk. Parasitoids failed to discriminate against hosts treated with LC₁₅ or LC₃₅ Btk in choice tests, but attacked fewer hosts treated with LC₇₀ Btk, paralyzing and parasitizing more healthy hosts, and laying more eggs on them. In contrast, a no-choice test revealed that more hosts treated with LC₃₅ and LC₇₀ Btk were paralyzed compared with control or LC₁₅-treated hosts, but the numbers of hosts parasitized and eggs laid did not vary among Btk treatments. Thus, females required an experience with healthy hosts, as they had in the choice test, to discriminate against diseased ones. We conclude that H. hebetor and Btk are compatible for joint application against H. armigera, which could potentially improve biological control of this pest.

中文翻译：

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接种不同浓度苏云金芽孢杆菌变种的Habrobracon hebetor（Hymenoptera：Braconidae）对棉铃虫幼虫的行为和发育反应。库尔斯塔克亚种（芽孢杆菌：Bacillacae）

苏云金芽孢杆菌柏林亚种。kurstaki（Btk）和Habrobracon hebetor说都是Helicoverpa armigera Hubner的生物防治剂。本研究通过检查接种Btk的宿主对He。hebetor雌性的可接受性并测试其对生命后代的负面生活史影响，评估了它们对这种害虫的联合施用的相容性。在用三种浓度的Btk（LC ₁₅，LC ₃₅和LC ₇₀处理）的盆栽鹰嘴豆植物上喂食第二龄棉铃虫幼虫72小时），然后用于寄生虫发育和寄生行为的生物测定。在用LC ₃₅和LC ₇₀ Btk处理的鹰嘴豆植株上饲喂寄主的寄主，但未在用LC ₁₅ Btk处理的植株上寄生虫的存活率显着降低，未成熟发育得以延长。寄生虫在选择测试中未能区分使用LC ₁₅或LC ₃₅ Btk治疗的宿主，但攻击较少的使用LC ₇₀ Btk治疗的宿主，使更多健康的宿主瘫痪和寄生，并在它们身上产卵。相反，无选择测试显示，更多接受LC ₃₅和LC ₇₀ Btk治疗的宿主与对照或LC ₁₅处理的宿主相比，它们被麻痹了，但是在Btk处理之间被寄生的宿主和产卵的数量没有变化。因此，女性需要有健康的宿主经验，就像他们在选择测试中所经历的那样，以区别患病的宿主。我们得出结论，H。hebetor和Btk可以与棉铃虫的联合施用相容，这可能会改善对该害虫的生物防治。