A <scp> <i>Rickettsiella</i> </scp> transinfection in <scp> <i>Rhopalosiphum padi</i> </scp> reduces fitness and alate production but not plant virus transmission

This Rickettsiella transinfection imposes deleterious host effects, while retaining the capacity to persist in populations through horizontal transmission. Although it does not influence BYDV transmission, the reduced alate formation and slower movement suggest potential impacts on pest spread and population structure. These findings advance our understanding of symbiont-host interactions and highlight the potential for endosymbiont manipulations to influence aphid ecology and management. © 2026 Society of Chemical Industry.