Mysterious phenomenon decimating honeybees in North America and Europe

British beekeepers, about to open their beehives for the first time this season, are braced to see how many of their honeybee colonies have survived the winter. An undiagnosed honeybee ailment is causing the deaths of thousands of honeybee colonies across the northern hemisphere and no-one knows the cause. The implications for agricultural pollination and production are huge.

Already this season beekeepers across 24 states in the USA are reporting heavy losses to a phenomenon being described as Colony Collapse Disorder. This follows a series of unexplained, but very severe, honeybee colony losses over the past few years in Poland, Greece, Italy, Spain and Portugal. Heavy losses in other countries are suspected to be going unreported.

“The situation is very serious, but no-one yet understands the cause of these widespread honeybee colony deaths,” explained Dr Max Watkins, Technical Director of Vita (Europe) Ltd, the largest honeybee health company in the world, and member of a European scientific  working group on honeybee losses. “Alleged causes range from harmful pesticides and increased solar radiation through ozone thinning, to falling queen fertility and use of unauthorised bee treatments. We really don’t know the answer – several causes may be at work and the only common factor known so far is that many honeybee colonies are dying. The phenomenon is alarming especially because agricultural pollination and therefore crop production levels are threatened.”

“It’s a real mystery,” continued Max Watkins. “We need beekeepers to report their losses and examine and analyse their colonies thoroughly. In the USA it has been difficult to obtain adequate samples and sufficient detailed reports. From records that are available, however, it is noticeable that many beekeepers have been using unauthorised treatments for varroa mites, a honeybee parasite. I’m sure that this is not the complete explanation, but it may be a significant contributory factor.”

The symptoms of the colony deaths are varying across Europe and North America and the losses generally come to light between late summer and early spring. In the USA this winter, colonies have dwindled as the older bees have died leaving behind the queen and young workers not yet ready to forage for pollen and nectar and insufficient in number to maintain the colony. In the UK past year, there were a few but significant examples of what became termed the Marie Celeste phenomenon – colonies simply disappearing from hives leaving no bees for post-mortem analysis.