4 new bee viruses discovered, link to CCD unclear

Scientists from UC San Fransisco have finished a ten month bee survey and last week published their findings in PLoS ONE. It turns out American bee hyves are swarmed with viruses and other pathogens.

In 20 colonies and over 70,000 hyves the researchers found 27 unique bee viruses, of which 4 were unknown. One of the newly discovered viruses, a strain of Lake Sinai, could be important though – as it turned out to be both common and very abundant, with individual bees carrying hundreds of millions of viral cells.

Among the other hyve invaders 6 different bacteria, 6 fungi, 4 mites and one parasitic fly were identified.

The study does not provide a clear connection to Colony Collapse Disorder, or CCD, the sudden die-off of bee colonies in many countries, which is being witnessed by beekeepers since 2006. According to the researchers it is still unclear what the baseline for the various infective microorganisms would be – so which part is ‘natural’ and which part is ‘disorder’.

Various experts have suggested environmental strains may have reduced the bees’ ability to fight off pathogens, making their colonies more susceptible to epidemic diseases. Stresses that have been associated with CCD include declining genetic honey bee variation (which does not explain CCD cases among wild bees and bumblebees), the invasion of exotic species, climate change and – which we reported on two days ago – a decline in flower biodiversity, mainly due to the rise of monoculture cropland.

Agriculture may have another big role to play with respect to deteriorating bee health: pesticides – especially insecticides – as these don’t discriminate between plagues and pollinators. Farmers may soon have to acknowledge you can’t have it both ways – as bees play a vital role in approximately one third of our food supply, especially the foods doctors tell us we should be eating more of, like fruits and vegetables – and CCD could lead to damaging production losses.

© Rolf Schuttenhelm | www.bitsofscience.org

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