Scientists launch fightback against mite that is wiping out our bees... by making it self-destruct

For 20 years it has ruthlessly attacked Britain's hives - wiping out millions of bees and bringing misery to Britain's honey producers.

But now scientists have launched the fight back against the invasive, blood sucking varroa mite parasite - the world's biggest killer of bees. They have developed a new technique that turns off genes in the pest's DNA, forcing the bugs to self-destruct.Although the treatment is still experimental, it could be developed into a treatment that kills the mites without harming bees within years.

Conservation groups are welcoming a breakthrough in the battle against the deadly mite responsible for decimating the honeybee population The breakthrough won't come soon enough for the UK's beleaguered honey bees.Bee numbers have fallen dramatically over the last few years. In England, the population has shrunk by 54 per cent since the 1980s as a result of the varroa mite, pesticides, industrial farming and disease.

Farmers say the decline could be disastrous for agriculture. Bees are vital for pollinating crops and are worth an estimated £200 million to farming each year.

Varroa mites look like brown crabs and are the biggest global killer of honeybees.

They were first found in Asian honeybees in 1904, but jumped to European honeybees in the 1950s. The parasites inject viruses into the bees which suppress their immune system - making them vulnerable to disease. They are 2mm long - the equivalent of a person carrying a small monkey on their back night and day. It can take just 1,000 mites to kill a colony of 50,000 bees Honey bees are worth £200m to the UK economy a year through pollinating crops.

The Varroa mite entered the UK in 1992 when it was found in Devon. Honey bee populations have dropped by 23 per cent since then, potentially costing the economy millions of pounds In 1992 there were 23,767 beekeepers and 151,924 colonies. In 2010 there have been 21,000 beekeepers, and 116,500 colonies. A mite can live on the back of an adult bee for months. In winter it feeds off the bee’s amber coloured blood. In summer it moves onto the developing brood to reproduce

It has been transported to every country in the world except Australi. It sits on the backs of honey bees - attacking their immune system and making them prone to disease. Its rise has been linked to the mysterious 'colony collapse disorder' - where entire hives die off. Attempts to wipe out the mite have failed because it is increasingly resistant to chemical treatments.

Dr Giles Budge, one of the UK's leading bee experts based in York, said the human equivalent of the mite would be having 'an organism on your back that's about the size of a dinner plate, which creates a hole through which it can feed and through which its family can feed', he said.

To tackle the pest, bee researchers harnessed a method called RNA interference. RNA is a chemical cousin of DNA and helps carry genetic messages around cells. The technique involves putting small pieces of RNA into an organism which silence a particular gene. In the experiment reported in the journal Parasites and Vectors, researchers soaked the varroa mites in solution containing the genetic material. The genetic code found its way into mites and switched off the gene they were targeting.

In the tests, the treatment targeted a non-lethal gene. However, they believe it be used to switch off a gene essential for the mite's life.

Dr Alan Bowman, of the University of Aberdeen who led the study said the technique fooled the immune system of the parasite into attacking itself. 'This can target the mite in the hive,' he said. 'It would be completely selective - it wouldn't target the bees and wouldn't affect any other pollinating insects, such as ladybirds.'

The mites hide in food that is stored in the hive for larvae. A beekeeper could put the treatment into food intended for the developing bees.

The new treatment would allow beekeepers to treat the parasites without harming the bees. Currently they have to use pesticides.

Prof Francis Ratnieks, a bee researcher from the University of Sussex, said it could be a long time before it was used on British bees.'It may be possible to use gene knockout techniques such as RNAi to learn more about the physiology of pests and to use this to develop ways of controlling them, maybe by the development and application of novel pesticides,' he told the BBC.

'But to do this is a huge undertaking involving many years of testing and certification.'

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.'