Conclusions
We found that V. ceranae prevalence in bumblebees was strongly
associated with the floral visitation behaviors of honeybees. More
honeybee visits and time spent interacting with both the pollen and
nectar contributed to higher V. ceranae prevalence in bumblebees,
despite honeybees visiting flowers less than bumblebees. These results
suggest that even a few visits by honeybees to shared crop flowers may
be having a disproportionately large effect on V. ceranaespillover from managed honeybee populations to wild bumblebee
populations in the agricultural landscapes. Our study provides a first
look at how specific pollinator visitation behaviors on flowers impact
the likelihood of parasite spillover among native pollinators in nature.
Understanding how the risk of V. ceranae infection for different
bee species changes with regard to their shared floral landscape with
honeybees is critical for reducing parasite spillover into declining
native bee populations. This knowledge may be particularly important in
agricultural settings where managed honeybees and wild pollinators from
the surrounding environment may frequently interact on crop flowers and
nearby hedgerows, creating potential hotspots for parasite transmission
on flowers.