Common facultative endosymbionts do not influence sensitivity of cereal aphids to pyrethroids

Cereal aphids, including the bird cherry-oat aphid, Rhopalosiphum padi, and grain Sitobion avenae, can transmit viruses that significantly reduce crop yields. To mitigate against yield losses, insecticides are routinely used to manage aphid populations. Aphids form relationships with endosymbionts confer fitness benefits or consequences aphid. Recent artificial inoculation experiments indicate could increase susceptibility insecticides, but this has not been explored using populations naturally infected endosymbionts. Here, we sampled aphids from an important cereal production region in Lower Saxony, Germany. We characterized endosymbiont profile of these conducted pyrethroid dose–response assays test hypothesis facultative insecticides. find level insecticide is highly variable S. avenae identify sensitive tolerant pyrethroids, collected same field. For R. evidence for decreased sensitivity representing first report reduced pyrethroids padi Central Europe. detected high infection frequencies 84% carry one 9% two associations Regiella insecticola, Fukatsia symbiotica, Hamiltonella defensa. However, do a link between susceptibility, indicating other factors may govern development resistance need alternative management strategies.