Clue found regarding mysterious bee disappearance

ScientificAmerican.com
September 07, 2007
By JR Minkel

Mysterious Honeybee Disappearance Linked to Rare Virus

Researchers isolate possible cause of "colony collapse disorder" but stress that other explanations are still in play

Bees sampled from beekeeping operations afflicted with the perplexing colony collapse disorder have turned up a possible cause: a bee virus discovered recently in Israel.

The mystery illness that has bedeviled U.S. beekeepers since 2006 may stem from a bee virus that apparently spread to the U.S. from Australia three years ago, according to a new study that marks the first big break in the puzzling case of the disappearing bees.

Researchers performed a sophisticated genetic comparison of healthy and diseased U.S. colonies that revealed the presence of Israeli acute paralysis virus (IAPV), an obscure but lethal bee bug, in almost all beekeeping operations affected by "colony collapse disorder" (CCD), but in only a single healthy one they examined.

"We haven't proven this is the cause. It is a candidate for being a trigger for CCD," says W. Ian Lipkin, director of the center for infection and immunology at Columbia University's Mailman School of Public Health, one of the study's lead members.
The disorder may also result from a combination of poor nutrition, pesticides and other factors, including infection, Lipkin and his colleagues say. They add that time-consuming tests are needed to determine whether IAPV can trigger CCD alone or in concert with other stressors, or whether certain combinations of stressors instead make hives vulnerable to the virus.

Israeli virologists discovered IAPV three years ago after investigating unexplained cases of dead bees piled in front of hives. The new study found the virus in samples of Australian bees, which were first imported to the U.S. three years ago...

Late last year, reports surfaced that adult honeybees were mysteriously abandoning commercial colonies, leaving ghost hives full of honey, larvae and unattended queens. The disorder wiped out an average of 45 percent of bees among the 23 percent of commercial U.S. beekeepers affected last winter...

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