Clue discovered in mystery of vanishing bees

By Mira Oberman
Agence France-Presse

CHICAGO–A major clue has been discovered in the case of the disappearing bees which are vanishing by the billions from colonies across the United States, according to new research released Thursday.

No, it isn’t radiation caused by cell phones, a change in flowering seasons because of global warming, poisons from genetically modified foods, or alien abductions, said researcher Diana Cox-Foster, who dismissed many of the theories bandied about since the bees began vanishing en masse last year.

But it could be partly due to a virus known as the Israeli acute paralysis virus (IAPV), unknowingly imported along with live bees from Australia and in royal jelly, a secretion produced by bees, imported from China, according to the study published Thursday in the online edition of Science magazine.

IAPV causes a bee’s wings to shiver before it becomes paralyzed and dies, usually just outside the hive.

Researchers believe that the virus may have mutated in the United States or combined with other “stressors” to cause billions of worker bees to die while out foraging for food, the study says.

While the study’s authors have not yet proven that the virus causes colony collapse disorder, they found that the presence of the virus in a bee colony helped predict colony collapse 96.1 percent of the time.

Because the virus was found in some healthy bee colonies, the scientists believe it is not acting alone.

Instead, they think colony collapse disorder is caused when a host of factors combine to weaken the worker bees.

A prime candidate is the varroa mite, a parasite that weakens the immune system of bees and is not present in Australia — where colony collapse disorder has not been a problem despite the presence of IAPV.

“We are concerned about the amount of chemicals coming into colonies that may lead to further stress,” Cox-Foster of Pennsylvania State University told reporters.

Another potential stressor is poor access to food due to recent droughts, she added.

Bee keepers first began noticing the sudden disappearance of their worker bees in 2004, shortly after live bee imports from Australia began.

They would open up the hives to find honeycombs filled with food reserves and capped broods but just a few newly emerged adults to attend to the queen.

Nearly a quarter of bee keeping operations across the country were hit by colony collapse over the past winter, claiming an average of 45 percent of their colonies.

The hardest-hit colonies are in large commercial operations which truck their bees across the country to pollinate the nation’s fruit and vegetable crops.

Cheap, imported honey had already driven down the number of bee keeping operations in the United States and the spread of colony collapse disorder has raised concerns that there will not be enough bees to pollinate about 14.6 billion dollars worth of crops.

“We’ve been able to meet the pollinating needs so far but we don’t have a large margin,” said study co-author Dr. Jeff Pettis of the US Department of Agriculture’s (USDA) research service.

There are no plans to try to limit the movement of bee keeping operations in order to try to contain the spread of the disorder, he added.

“The value of pollinating and the need to move bees to crops in bloom outweighs the localization need,” he said in a conference call with reporters.

And it probably wouldn’t work even if they tried, he said.

“It’s hard to control the movement of flying insects.”

Instead, the USDA is considering a ban on imports from China and Australia and looking into breeding bees resistant to the virus, something Israel has already begun working on.

“We’re not going to likely come up with a treatment for viruses in bees so we’ll have to manage bee health,” Pettis said, adding that the USDA is working with bee keepers to improve nutrition and reduce exposure to parasites and pesticides.

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