July 18, 2013
Tighter Controls On Bee Imports Needed To Reduce Disease Risk To Native Populations
Lee Rannals for redOrbit.com - Your Universe Online
Researchers, publishing a study in the Journal of Applied Ecology, wrote that stricter controls over bee imports are needed in order to prevent diseases from spreading to the native bumblebee and honeybee populations.Farmers bring in commercially-produced and imported bumblebees for pollination of greenhouse crops like tomatoes. These bees are used to enhance pollination of other food crops, such as strawberries, and are marketed for use in people's gardens. Between 40,000 and 50,000 commercially-produced bumblebee colonies are imported annually to the UK each year and over a million colonies are sold worldwide.
In order to test the effects of bringing in imported bees, researchers bought 48 colonies of buff-tailed bumblebees (Bombus terrestris) from three European producers. Some colonies were a subspecies native to the UK and others were non-native. Although all the bees were said to be disease-free, DNA tests showed that 77 percent of the colonies were found to be carrying parasites.
Screening revealed that the imported bumblebee colonies carried a variety of parasites. The team conducted a series of carefully controlled laboratory experiments to find out whether the parasites carried by the commercially-produced bumblebee colonies were viable and able to infect other bees.
"We found that commercially-produced bumblebee colonies contained a variety of microbial parasites, which were infectious and harmful not only to other bumblebees, but also to honeybees," said Peter Graystock of the University of Leeds, who is lead author of the study.
The authors say that their study shows that current regulations and protocols governing bumblebee imports are not effective. Natural England licenses are only required for the non-native species and do not require screening to ensure compliance.
The team recommends that producers improve disease screening and develop a parasite-free diet for the bees, while while at the same time recommending that regulatory authorities strengthen measures to prevent importation of parasite-carrying bumblebee colonies. They said authorities need to include checking bees on arrival in the UK and extend regulations to cover imported colonies of the native subspecies.
"If we don't act, then the risk is that potentially tens of thousands of parasite-carrying bumblebee colonies may be imported into the UK each year, and hundreds of thousands worldwide," says Professor William Hughes of the University of Sussex, who was co-author of the study. "Many bee species are already showing significant population declines due to multiple factors. The introduction of more or new parasite infections will at a minimum exacerbate this, and could quite possibly directly drive declines."
In 2007 scientists pointed out that colony collapse disorder began in 2004, which was the same year US beekeepers began importing bees from Australia.