Co-occurrence of high levels of deformed wing virus genotype A and B in both managed and wild social bees

Bees are key pollinators that support global food production and plant biodiversity, yet wild pollinator populations are declining due to anthropogenic pressures, including habitat loss, pesticide use, and emerging disease. In honey bees (Apis mellifera), viral disease dynamics have been strongly influenced by the parasitic mite Varroa destructor, which vectors Deformed Wing Virus (DWV) and has altered viral community composition. DWV exists as multiple genotypes, most notably DWV-A and DWV-B, with recent studies suggesting a global shift towards DWV-B dominance. Here, we investigated the prevalence and viral load of DWV-A and DWV-B in honey bees and a wild bumblebee species across ten protected calcareous grassland sites in the UK to evaluate patterns of DWV genotype and the extent of potential pathogen spillover into wild bee populations. Contrary to expectations of DWV-A decline, both genotypes were highly prevalent in honey bees and bumblebees, with frequent co-detections observed. Notably, Bombus lapidarius exhibited higher DWV-A viral loads and similar prevalence to honey bees, indicating a possible role in the maintenance of DWV-A in UK grasslands. These findings challenge assumptions of a shift towards DWV-B predominance and highlight the importance of including wild pollinators in viral monitoring to better understand potential pathogen spillover and multi-host dynamics in managed and wild bee communities.