The endosymbiont Serratia symbiotica improves aphid fitness by disrupting the predation strategy of ladybeetle larvae

• Published in: Insect science Vol. 31; no. 5; pp. 1555 - 1568
• Main Authors: Wang, Zheng‐Wu, Zhao, Jin, Li, Guang‐Yun, Hu, Die, Wang, Zi‐Guo, Ye, Chao, Wang, Jin‐Jun
• Format: Journal Article
• Language: English
• Published: Australia Wiley Subscription Services, Inc 01.10.2024
• Subjects: Adaptability; Animals; aphids; Aphids - microbiology; Aphids - physiology; Bacteria; Biological control; Biological effects; Coleoptera - microbiology; Coleoptera - physiology; defense; Disruption; Endosymbionts; Environmental conditions; Fecundity; Foraging behavior; Host-parasite interactions; Insects; Larva - growth & development; Larva - microbiology; Larva - physiology; Larvae; Pests; Predation; predator; Predators; Predatory Behavior; Serratia; Serratia - physiology; Serratia symbiotica; Symbionts; Symbiosis; Trophic relationships; biological control; Serratia symbiotica; defense; predator; aphids
• ISSN: 1672-9609; 1744-7917; 1744-7917
• DOI: 10.1111/1744-7917.13315

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. Harboring the facultative symbiont Serratia symbiotica contributes to: (i) enhanced growth and fecundity of aphids, albeit at the cost of a shorter lifespan; (ii) hindered development of their predators; (iii) inhibited predation capacity of predators; and (iv) altered foraging behavior of predators.