Stricter controls over bumblebee imports to the UK are urgently required to prevent diseases spreading to native bumblebees and honeybees, scientists have warned. The call follows the discovery of parasites in over three-quarters of imported bumblebee colonies they tested. The study - the first of its kind in the UK - is published today in the Journal of Applied Ecology.
While wild species of bees and other insects pollinate many crops, commercially-reared and imported bumblebees are essential for pollination of greenhouse crops such as tomatoes. They are also used to enhance pollination of other food crops such as strawberries, and are now marketed for use in people's gardens. The trade is large and widespread: 40-50,000 commercially-produced bumblebee colonies each containing up to 100 worker bees are imported annually to the UK, and more than one million colonies are sold each year worldwide.
The team of researchers from the universities of Leeds, Stirling and Sussex 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. 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.
Screening revealed that the imported bumblebee colonies carried a range of parasites including the three main bumblebee parasites (Crithidia bombi, Nosema bombi and Apicystis bombi), three honeybee parasites (Nosema apis, Ascosphaera apis and Paenibacillus larvae), and two parasites which infect both bumblebees and honeybees (Nosema ceranae and deformed wing virus).
After the screening tests, the team conducted a series of carefully controlled laboratory experiments to find out whether the parasites carried by the commerc
|Contact: Becky Allen|