For longtime commercial beekeeper Eric Olson of Yakima, no sting is as painful as the one he felt last winter when he discovered his hives had gone silent. Peering into each box, he saw the queen and a mere scattering of her worker-bee offspring; tens of thousands of adult bees - gone.

"They just up and left,” said Olson. "I’m 68 years old and it was the biggest shock of my life. It wasn’t just economic. It was psychological. I love my bees.”

Silence of the hives

Since 2006, honey bees around the globe have been disappearing at alarming rates, as hives humming with activity one month dissolve into ghost towns the next. Colony collapse disorder, or CCD, contributes to the decimation of roughly a third of the nation’s bee colonies annually, according to the Apiary Inspectors of America.

The mysterious malady threatens more than beekeepers’ livelihoods. Not only do honey bees make honey, but one third of what we eat comes from crops and nuts pollinated by them, according to the U.S. Department of Agriculture’s Agricultural Research Service. Without honey bees to pollinate, many crops, including the prized apples of Washington state, would crash.

"For honey bees to fly off and desert their colonies — that just doesn’t happen,” said Olson, a beekeeper for 31 years who runs one of the Northwest’s largest beekeeping businesses. "The theory is that they’re dying in the fields before they can make it back, but the question is, how come?”

In a mystery worthy of an "X-Files” TV episode, Olson has turned to Washington State University for answers. In 2008, he and his wife Sue "knocked on doors from here to Olympia,” he said, raising nearly $350,000 to help start WSU’s Honey Bee Colony Health Diagnostic Laboratory, headed by entomologist Steve Sheppard.

A member of an international group of scientists that published the first complete DNA sequence of the honey bee, Sheppard knows a thing or two about the insect that Olson reveres. It didn’t take long for him and his research team to confirm that it’s not one culprit that’s responsible for the die-offs, but a combination.

For example, pesticide exposure weakens the bees, and then a fungal pathogen, Nosema ceranae, kills them. This is not the single cause of colony collapse, Sheppard said, but the findings, published in the January issue of the Journal of Invertebrate Pathology, have narrowed the list of suspects.

"We know the combination of those two stressors contributes to CCD. It’s a combination we see often, but not always,” he said.

And so, because multiple pesticide residues build up on the wax of the honeycombs, Sheppard has recommended that bee keepers change the combs more frequently.