Does keeping non-native honey bees in Iowa prairies endanger wild bees through exposure to viruses?

Populations of wild and managed pollinators are declining in North America, due in part to a loss of flowering resources. Tallgrass prairies can provide floral resources for managed honey bees, as well as wild bees such as bumble bees. However, if honey bees are kept on or near prairies, they could transfer diseases to wild bees. Information is lacking on the potential for honey bees to transmit diseases to wild bees in the context of native habitats. We quantified viral levels in honey bees and bumble bees at prairie sites with and without honey bee hives. Bumble bees from both site types showed low levels of all viruses measured, much lower than those of honey bees. However, bumble bees collected at sites with honey bee hives present had higher levels of deformed wing virus compared to bumble bees at sites with no hives present. These data suggest that the presence of honey bees in tallgrass prairie could increase exposure of wild bees to viruses. This study, along with future studies on direct effects of virus infection on bumble bee health, could be useful for informing decisions about both honey bee management and wild bee conservation