When attacked by herbivores, plants emit volatiles to attract parasitoids and predators of herbivores. However, our understanding of the effect of plant volatiles on the subsequent behaviour of conspecific parasitoids when herbivores on plants are parasitized is limited. In this study, rice plants were infested with gravid females of the brown planthopper (BPH) Nilaparvata lugens for 24 hr followed by another 24 hr in which the BPH eggs on plants were permitted to be parasitized by their egg parasitoid, Anagrus nilaparvatae ; volatiles from rice plants that underwent such treatment were less attractive to subsequent conspecific parasitoids compared to the volatiles from plants infested with gravid BPH females alone. Chemical analysis revealed that levels of JA and JA‐Ile as well as of four volatile compounds—linalool, MeSA, α‐zingiberene and an unknown compound—from plants infested with BPH and parasitized by wasps were significantly higher than levels of these compounds from BPH‐infested plants. Laboratory and field bioassays revealed that one of the four increased chemicals—α‐zingiberene—reduced the plant's attractiveness to the parasitoid. These results suggest that host plants can fine‐tune their volatiles to help egg parasitoids distinguish host habitats with parasitized hosts from those without.

中文翻译：

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寄主植物会改变其挥发物，以帮助孤卵拟寄生虫区分具有寄生寄主的生境和没有寄生寄主的生境。

当受到草食动物的攻击时，植物会散发挥发物，以吸引寄生性动物和草食动物的天敌。但是，我们对植物草食性被寄生时对植物挥发物对同种寄生虫随后行为的影响的理解是有限的。在这项研究中，水稻植株被褐飞虱（BPH）Nilaparvata lugens的雌性雌虫侵染了24个小时，然后再过24个小时，其中允许植物上的BPH卵被其寄生卵的拟寄生虫Anagrus nilaparvatae寄生。; 与仅受妊娠BPH雌性侵染的植物中的挥发物相比，经过这种处理的水稻植物中的挥发物对随后的同种寄生性寄生虫吸引力较小。化学分析表明，受BPH侵害并被黄蜂寄生的植物中的JA和JA-Ile以及四种挥发性化合物（芳樟醇，MeSA，α-姜油烯和一种未知化合物）的水平显着高于BPH中这些化合物的水平出没的植物。实验室和现场生物测定表明，四种增加的化学物质之一-α-姜油烯降低了植物对寄生虫的吸引力。这些结果表明，寄主植物可以对其挥发物进行微调，以帮助卵类寄生虫区分具有被寄生虫的寄主生境和没有被寄生虫的寄主生境。