New research suggests diseases common in managed honeybees have now spread to the widespread bumble bee population in the U.K.
"Wild and managed bees are in decline at national and global scales. Given their central role in pollinating wildflowers and crops, it is essential that we understand what lies behind these declines. Our results suggest that emerging diseases, spread from managed bees, may be an important cause of wild bee decline," Doctor Matthias Fürst and Professor Mark Brown from Royal Holloway University of London, said in a Biotechnology and Biological Sciences Research Council news release.
The researchers collected bumble bees from 26 sites across the U.K. to make their findings.
The team looked at common diseases to see if they could spread from honeybees; they found deformed wing virus (DWV) and the fungal parasite Nosema ceranae could both infect worker bumblebees and shorten their lifespan.
"One of the novel aspects of our study is that we show that deformed wing virus, which is one of the main causes of honeybee deaths worldwide, is not only broadly present in bumblebees, but is actually replicating inside them. This means that it is acting as a real disease; they are not just carriers," Doctor Fürst said.
The team looked at genetic differences between DWV DNA in different bee populations. They found honeybees higher background levels of both the fungus and the virus. Bumble bees and honeybees share genetic strains of the microbes and infections in honeybees tend to predict outbreaks in bumblebees.
"What our data show is that these same pathogens are circulating widely across our wild and managed pollinators. Infected honeybees can leave traces of disease, like a fungal spore or virus particle, on the flowers that they visit and these may then infect wild bees," Professor Mark Brown of Royal Holloway University of London said in the news release.
"National societies and agencies, both in the [U.K.] and globally, currently manage so-called honeybee diseases on the basis that they are a threat only to honeybees. While they are doing great work, our research shows that this premise is not true, and that the picture is much more complex. Policies to manage these diseases need to take into account threats to wild pollinators and be designed to reduce the impact of these diseases not just on managed honeybees, but on our wild bumblebees too," he said.
