Parasitic wasp-associated symbiont affects plant-mediated species interactions between herbivores

Microbial mutualistic symbiosis is increasingly recognised as a hidden driving force in the ecology of plant–insect interactions. Although plant‐associated and herbivore‐associated symbionts clearly affect interactions between plants and herbivores, the effects of symbionts associated with higher trophic levels has been largely overlooked. At the third‐trophic level, parasitic wasps are a common group of insects that can inject symbiotic viruses (polydnaviruses) and venom into their herbivorous hosts to support parasitoid offspring development. Here, we show that such third‐trophic level symbionts act in combination with venom to affect plant‐mediated interactions by reducing colonisation of subsequent herbivore species. This ecological effect correlated with changes induced by polydnaviruses and venom in caterpillar salivary glands and in plant defence responses to herbivory. Because thousands of parasitoid species are associated with mutualistic symbiotic viruses in an intimate, speci...

微生物互利共生关系日益被认定为植物-昆虫互作生态系统中隐匿的核心驱动因子。尽管与植物、植食动物共生的共生体显然会调控植物与植食动物间的互作，但针对更高营养级共生体的效应却长期被极大忽视。在第三营养级中，寄生蜂是一类极为常见的昆虫类群，它们可将共生病毒（多DNA病毒，polydnaviruses）与毒液注入植食性宿主体内，以保障寄生蜂子代的发育。本研究证实，这类第三营养级共生体可与毒液协同发挥作用，通过抑制后续植食动物物种的定殖，进而影响植物介导的种间互作。该生态效应与多DNA病毒和毒液诱导的毛虫唾液腺变化，以及植物针对植食性取食的防御响应变化密切相关。由于全球已有数千种寄生蜂物种与互利共生病毒形成紧密的专性...