A persistent bacterialRegiellatransinfection in the bird cherry-oat aphidRhopalosiphum padiincreasing host fitness and decreasing plant virus transmission

The bird cherry-oat aphid, Rhopalosiphum padi , is a major pest of agriculture due to its ability to directly damage crops and transmit plant viruses. As industries move away from chemical pest control, there is interest in exploring new options to suppress the impact of this pest. Here we describe the production of a transinfected line of R. padi carrying the bacterial endosymbiont, Regiella insecticola , originating from the green peach aphid, Myzus persicae . We show that Regiella increases the fitness of its novel host despite decreasing fitness in its native host. Regiella also shows a low level of horizontal transmission. Importantly the infection suppresses the ability of R. padi to transmit the barley yellow dwarf virus which damages wheat plants. This transinfection could be released to suppress virus transmission by aphids with its ability to persist and spread, making it potentially suitable for wide area release.