As a colonial, social species honey bees are plagued by a variety of viruses. It is suspected that viruses may be behind colony collapse disorder. Bumble bees are also social, and related to honey bees. New work is showing that they are susceptible to many of the same diseases honey bees are, and that viruses can pass between species.
Particularly alarming is that the virus seems able to survive in pollen grains, moving from infected bees to uninfected bees and thereby spreading. A number of floral species were found to contain viruses– and the viruses were not just honey bee specific, but affected carpenter bees, mining bees and sweat bees, even some wasps. While the viruses may not be able to survive in pollen for very long, when flowers are in peak bloom, lots of pollinators may visit in bursts, leading to high rates of transfer.
Should we be concerned about this? In short, yes– spillover effects of disease from managed bumble bee colonies in greenhouses have been shown to harm nearby native, unmanaged bumble bee populations. Of course, wild populations could also serve as disease reservoirs passing diseases back to honey bees. The authors of the article highlight the need to promote health in both managed and unmanaged populations, and recognize the overlap between the two. Healthy bee populations are important to our food supply.
This paper was written in 2010- I’ll try to look into newer findings soon!