Identification of reservoirs of vectors and viruses responsible for beet yellows

The ban on neonicotinoids used against aphids transmitting viruses responsible for beet yellows has spurred significant efforts to identify alternatives. This study, conducted from 2021 to 2023 in major beet-growing regions, aimed to identify the winter reservoirs of vectors and viruses for integration into management strategies. The results show that oilseed rape and mustards are major reservoirs of aphids colonising sugar beet in spring, although they are not the sources of beet viruses. Sugar beet volunteers and, potentially, phacelia (and faba bean for BtMV) appear as combined reservoirs of both vectors and beet viruses. The potential role of wild beets seems limited due to the specificity of the viral populations infecting them. This work provides clues to better understand epidemic dynamics and guide disease management.