The larval stages of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) cause more direct feeding damage to plants than the adults. We, therefore, investigated the behaviour-modifying effects on second instar larvae of two jasmonic acid derivatives. The artificial application of methyl jasmonate and cis-jasmone, both at 1 % concentration, deterred the larvae from settling in a dual choice bean leaf disc assay. We observed a dose-dependent feeding deterrence of both jasmonates and calculated the concentration required to reduce the feeding damage by 50 % relative to the control treatment (FDC₅₀) for each jasmonate. The feeding damage was reduced by the application of cis-jasmone at 1 % concentration, but not by the jasmonates at the respective FDC₅₀ in no-choice leaf disc bioassays. However, significantly more larvae left jasmonate-treated whole potted bean plants by migrating to the soil compared with control plants. Our results may be exploited extending behavioural manipulation by using plant compounds in thrips control programmes to the full lifecycle of the pest. Plant compounds could be used in integrated and biological pest management strategies against F. occidentalis in combination with the application of various above and below ground control measures.

中文翻译：

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Frankliniella occidentalis Pergande 幼虫对茉莉酸甲酯和顺式茉莉酮的行为反应。

Frankliniella occidentalis Pergande (Thysanoptera: Thripidae)的幼虫阶段比成虫对植物造成更直接的摄食损害。因此，我们研究了两种茉莉酸衍生物对二龄幼虫的行为改变作用。茉莉酸甲酯和顺式茉莉酮（均为 1% 浓度）的人工施用阻止了幼虫在双重选择豆叶盘测定中沉降。我们观察到两种茉莉酮酸盐的剂量依赖性摄食威慑，并计算了相对于对照处理 (FDC ₅₀ ) 将每种茉莉酸盐的摄食损害降低 50% 所需的浓度。应用顺式减少了摄食损害-浓度为 1% 的茉莉酮，但在非选择叶盘生物测定中，茉莉酮酸盐在各自的 FDC ₅₀处不是。然而，与对照植物相比，明显更多的幼虫通过迁移到土壤中离开茉莉酸盐处理的整株盆栽豆植物。我们的结果可以通过在蓟马控制程序中使用植物化合物将行为操纵扩展到害虫的整个生命周期。植物化合物可与各种地上和地下控制措施的应用相结合，用于针对F. occidentalis的综合和生物害虫管理策略。