Mystery killer plagues bee hives

As whole colonies disappear, N.C. crops could suffer

MEBANE -- Jeff Lee rents out his honeybees each spring to pollinate crops of blueberries, cucumbers, watermelons and cantaloupes. Many are on the job in California right now pollinating almond trees.

But a few months ago, Lee noticed a troubling trend. Whole hives were disappearing -- apparent victims of a mysterious disorder killing tens of thousands of honeybee colonies across the country.

When he would open a bee box, it would be empty. Lee estimates he has lost about 300 of his 1,000 colonies of bees in the past six months.

"They are physically gone," said Lee, owner of Lee's Bees, as he poured sugar syrup into the hives to feed the bees. "That is what makes it different from other diseases."

The loss of bees in North Carolina and other states appears to be an outbreak of a disorder called colony collapse syndrome. And it's raising alarm among farmers who depend on insects to pollinate their crops. In addition to producing honey, bees are a vital link in the agricultural food chain, pollinating about a third of the food people eat.

Farmers contract with commercial beekeepers to set up hives in their fields for several weeks when crops are blooming. As bees fly from blossom to blossom in search of nectar, they ferry pollen from plant to plant, fertilizing them to bear fruit.

"We've certainly seen bees dying without an explanation," said Adolphus Leonard, a bee inspector with the N.C. Department of Agriculture. He said he was seeing bee losses in Eastern North Carolina between 30 percent and 40 percent. "It's been the worst this year, and it may be related to losses the last couple of years. It's going to affect the availability of bees for pollination this spring."

Some crops, such as blueberries and apples, require insect pollination. Other crops produce greater yields when insects are involved. Real money is at stake. The value of North Carolina's blueberry crop, for instance, was $36.7 million in 2005, according to state agricultural statistics.

N.C. State entomologists estimate that honeybees directly account for about $154 million in the state's annual crop productivity.

"If you remove honeybees from the equation, you'd lose about 95 percent of the yield," said David Tarpy, a bee specialist and assistant professor in the Department of Entomology at N.C. State University. "That's why this is such a problem."

Mt. Olive Pickle Company purchases more than 30 million pounds of cucumbers a year from North Carolina farmers. Typically, one hive of bees works about an acre of cucumbers.

"You have to have bees to produce cucumbers in North Carolina," said Lynn Williams, a spokesperson for Mt. Olive Pickle Company. "It would certainly be a concern for us if all of a sudden the bees disappeared. The varieties we use do require pollination."

"This threat is new to us," she said.

Other threats have menaced the bee population in recent years. Since the mid-1980s, honeybees have been plagued by two exotic parasitic mites that can wipe out entire colonies if left untreated. Because of mites, the number of managed hives in the state has declined from 180,000 before the mite introduction to about 100,000 currently, according to N.C. State entomologists.

The mites have devastated most wild bees, making it necessary for farmers to rent bees from commercial beekeepers such as Lee to ensure successful pollination.

"A lot of people think beekeeping is strictly for hobbyists and to make honey," Tarpy said. "They don't realize the connection to the greater agricultural community."

Culprit unknown

The new killer is a puzzle. Researchers aren't exactly sure even how long it's been around.

"We're really concerned about it," Charles Heatherly, president of the N.C. State Beekeepers Association, which has about 2,000 members, mostly hobbyists. "Every time you turn around, it seems like another plague is affecting bees."

Tarpy said beekeepers regularly experience losses, but the colonies dying from the current plague don't show the typical symptoms of mites. Tarpy said researchers at Penn State had found unusual internal symptoms when dissecting samples of bees, including some from North Carolina, when describing the disorder.

"We can't call it a disease," Tarpy said. "The culprit is as yet unknown. It could be one thing or multiple things. We're not really sure."

That's little comfort for Samuel Cox of Edenton, one of the state's largest commercial beekeepers, who has unsuccessfully sought technical help to stem his losses. Cox said about half of his 2,000 colonies have been wiped out since last summer.

"The beekeeping industry is in trouble because of some unknown out there killing our hives," Cox said. "We've treated them and done everything we know to do. We're rather frustrated. There is no question, the number of bees are going downhill fast."