Science & Environment

Cash to help fight pervasive honey bee pest

Varroa mite on honey bee
Image caption Varroa mites prey on bees and make them vulnerable to many diseases

Scientists are to try to turn a honey bee parasite's natural defences against itself in a bid to beat the pest.

University of Aberdeen researchers have won £250,000 to study how to subvert the varroa mite's immune system.

The blood-sucking varroa mite is endemic in many honey bee colonies and transmits lethal viruses to the bees.

Novel ways to tackle varroa are needed because mites are becoming resistant to existing chemical treatments.

The cash will be used to extend a completed study that showed how to target specific genes used by the mite.

Potential targets

So far, said Dr Alan Bowman of the University of Aberdeen who is leading the project, this "knock-down" approach has only been used to home in on non-lethal genes.

"The next step is to continue finding which are the best genes that will kill them quickly at very low doses and then we'll move on out to field trials when we'll be working with the National Bee Unit," said Dr Bowman.

The knock-down technique attempts to trick part of the bug's immune system into thinking that one of its genes is a virus.

Typically the part of the immune system being subverted only tackles external threats in the form of a certain types of RNA-based viruses.

As active genes also use RNA, it should be possible to subvert this defence mechanism by making it think one of the genes keeping the mite living is actually an invader.

Varroa mites' genomes are being sequenced to discover which genes are being actively expressed and are potential targets.

Dr Bowman hoped to have identified likely genes by the autumn and to start small-scale trials in 2013.

Beekeepers are being asked to send in live varroa mites so the researchers have a stock of bugs on which to test candidate treatments.

Dr Bowman said it was unlikely that the research would produce a treatment that would completely rid hives of the pest.

"I do not think we are expecting any silver bullets and it's probably the wrong approach to look for them these days," he said. "It'll be another piece in the arsenal and at the moment it's a very small arsenal."

Max Watkins, technical director of Vita Europe, which is providing some of the research money, said finding treatments that kill mites but leave bees and the environment unharmed was very difficult.

"The challenge is heightened because the relatively short life cycle of the varroa mite means that resistance to a single treatment can often develop quite quickly," he said.

Honey bees, solitary bees and bumble bees play a hugely important role in pollinating crops, said Friends of the Earth as it kicked off its Bee Cause campaign.

The pressure group estimates that it would cost the UK about £1.8bn a year to hand-pollinate crops if all bees died out.

It has called on David Cameron to back a national bee action plan that would limit urban expansion and pesticide use.

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