http://www.digitaljournal.com/article/354708

British honeybees under threat from imported bumblebees

Posted Jul 19, 2013 by Tim Sandle
Imported bumblebees into the U.K. are spreading diseases that are affecting native bumblebees and honeybees, according to a new study.
Bee a Kew gardens
Bee a Kew gardens
Commercially-reared bumblebees are regularly imported into countries like the U.K. for the pollination of greenhouse crops such as tomatoes and strawberries. A new aspect to the import of these bees is for companies to sell them to householders for use in their gardens.
However, many of these imported bees carry diseases and these diseases are affecting the native bee populations in the U.K., according to the Guardian. The extent of the problem was shown by a research team who purchased 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. All were meant to be disease-free, but when they were tested using DNA technology, 77% of the colonies were found to be carrying parasites. Parasites were also found in the pollen food supplied with the bees.
These parasites were later shown to be infectious and harmful not only to other bumblebees, but also to honeybees. Although licenses are required for bee imports, the report by the researchers suggests that the controls are ineffectual.
Globally many bee species are showing significant population declines due to multiple factors (including pesticides, loss of habitat and more intensive agriculture). The introduction of more or new parasite infections into countries like the U.K. will lead further losses to the bee populations. Australia has recently placed strong restrictions on the imports of bees due to similar concerns.
The research is important because bees sustain life on the planet by pollinating crops. Bumblebees are among the most ecologically and economically important pollinators in temperate regions. The honeybee (Apis mellifera) is a social bee that forms large colonies that overwinter. It can be kept in hives and is the source of honey and beeswax.
The report has been published in the Journal of Applied Ecology and was based on research carried out at the universities of Leeds, Stirling and Sussex. The paper is titled "The Trojan hives: pollinator pathogens, imported and distributed in bumblebee colonies."