Genetic breakthrough in fight against honeybee killer

A breakthrough in the battle against a deadly mite responsible for decimating the honeybee population has been welcomed by conservation groups.

The varroa mite is the biggest killer of honeybees and has become resistant to medication developed to destroy it. But now scientists have identified a genetic technique that could stop the mite in its tracks.

Researchers from the government's National Bee Unit and Aberdeen University have worked out how to "silence" natural functions in the mites' genes.

Alan Bowman, from the University of Aberdeen, said: "Introducing harmless genetic material encourages the mites' own immune response to prevent their genes from expressing natural functions. This could make them self-destruct.

"This approach targets the mites without harming the bees or, indeed, any other animal."

Giles Budge, from National Bee Unit, part of the Food and Environment Research Agency (Fera), agreed. "This cutting-edge treatment poses no threat to the bees.

"With appropriate support from industry and a rigorous approval process, chemical-free medicines could be available in five to 10 years."

The mite, which looks like a tiny brown crab, hitches a ride on the bee, draining its blood and weakening its immune system. It takes just 1,000 mites to kill a colony of 50,000 bees.

Honeybees play a vital role in food production as crop pollinators but populations fell between 10 and 15% in the two years to 2009.

The mite is particularly deadly during the winter months as it strikes when bee numbers are depleted and colonies do not have enough bees to keep warm.

The mite originally attacked the Asian honeybee but jumped to the European honeybee, which has a poor natural defense. It injects viruses, suppresses the bees' immune system and feeds on blood. Beekeepers use chemical controls but can never eradicate it and over the past decade the varroa developed resistance to some medication. (At right: distribution of varroa mite in red)

The environment minister Lord Henley said: "Bees are essential to putting food on our table and worth £200m to Britain every year through pollinating our crops.

"This excellent work by UK scientists will keep our hives healthy and bees buzzing."

The process uses the Nobel Prize-winning theory "RNA interference", which controls the flow of genetic information. So far the "silencing" has worked with a neutral varroa gene, which has no significant effect on the mite.

Scientists now need to target a gene with the specific characteristics that are perfect to force the varroa to self-destruct. Tests by other scientists have shown the treatment can be added to hives in bee feed. The bees move it into food for their young, where the varroa hides.

Martin Smith, president of the British Beekeepers Association, said: "While this research is at the early stage, we are pleased that work is being undertaken to try and control the varroa mite which remains the largest threat to beekeeping in this country. We look forward to seeing further work in this area."

Source:
The Guardian,"Genetic breakthrough in fight against honeybee killer", accessed December 22, 2010