Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China.
International Joint Laboratory of China-Belgium on Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China.
Insect Sci. 2024 Oct;31(5):1555-1568. doi: 10.1111/1744-7917.13315. Epub 2024 Jan 9.
Aphids, the important global agricultural pests, harbor abundant resources of symbionts that can improve the host adaptability to environmental conditions, also control the interactions between host aphid and natural enemy, resulting in a significant decrease in efficiency of biological control. The facultative symbiont Serratia symbiotica has a strong symbiotic association with its aphid hosts, a relationship that is known to interfere with host-parasitoid interactions. We hypothesized that Serratia may also influence other trophic interactions by interfering with the physiology and behavior of major predators to provide host aphid defense. To test this hypothesis, we investigated the effects of Serratia on the host aphid Acyrthosiphon pisum and its predator, the ladybeetle Propylaea japonica. First, the prevalence of Serratia in different A. pisum colonies was confirmed by amplicon sequencing. We then showed that harboring Serratia improved host aphid growth and fecundity but reduced longevity. Finally, our research demonstrated that Serratia defends aphids against P. japonica by impeding the predator's development and predation capacity, and modulating its foraging behavior. Our findings reveal that facultative symbiont Serratia improves aphid fitness by disrupting the predation strategy of ladybeetle larvae, offering new insight into the interactions between aphids and their predators, and providing the basis of a new biological control strategy for aphid pests involving the targeting of endosymbionts.
蚜虫是全球重要的农业害虫，它们拥有丰富的共生资源，可以提高宿主对环境条件的适应能力，同时控制宿主蚜虫与天敌之间的相互作用，从而显著降低生物防治的效率。兼性共生菌 Serratia symbiotica 与它的蚜虫宿主有着密切的共生关系，这种关系已知会干扰宿主-寄生蜂的相互作用。我们假设 Serratia 也可以通过干扰主要捕食者的生理和行为来为宿主蚜虫提供防御，从而影响其他营养相互作用。为了验证这一假设，我们研究了 Serratia 对宿主蚜虫 Acyrthosiphon pisum 和其捕食者日本龟蜡蚧的影响。首先，通过扩增子测序证实了不同 A. pisum 群体中 Serratia 的流行情况。然后，我们表明携带 Serratia 可以提高宿主蚜虫的生长和繁殖力，但降低了寿命。最后，我们的研究表明，Serratia 通过阻碍捕食者的发育和捕食能力，并调节其觅食行为，为蚜虫提供防御，抵御日本龟蜡蚧。我们的研究结果表明，兼性共生菌 Serratia 通过破坏龟蜡蚧幼虫的捕食策略来提高蚜虫的适应性，为蚜虫及其天敌之间的相互作用提供了新的见解，并为涉及针对内共生体的蚜虫害虫的新生物防治策略提供了基础。
