Honey bee associated viruses are unlikely to impact bumble bee colonies while habitat heterogeneity supports their resilience

Virus host shifts from managed honey bees, Apis mellifera, are thought to contribute to the decline of wild pollinators. However, data on the impact of such viruses on wild pollinators remain scarce, and how landscape structure may affect virus transmission is poorly understood. We experimentally deployed bumble bee colonies in an agricultural landscape to study changes in the bumble bee virome under varying habitat composition and configuration. The results show a decline in prevalence and viral loads of honey bee associated viruses, while viruses common in Bombus spp. increased during field exposure. Honey bee associated viruses had no effect on colony development, suggesting that immediate impacts are unlikely in the field. Notably, we further demonstrate that increased habitat diversity results in fewer viruses in Bombus colonies. To mitigate the decline of bumble bees and other wild pollinators, we suggest focusing conservation efforts on habitat diversification and restoration.