Last fall, there was something wrong with Ed Menefee's honeybees.

Some of the 800 hives he has at Bar Bell Bee Ranch in Squaw Lake in Itasca County were full of amber-colored honey, but the combs were quiet, largely absent of their customary encrustation of plump gold-and-black bodies. "There was plenty [of honey] in storage, but no bees," Menefee said.

The bees simply hadn't come back to claim the food they had stored all summer.

Situations eerily similar to Menefee's have been occurring across 22 states, according to the United States Department of Agriculture; honeybees have been mysteriously disappearing from their colonies without explanation. Presumably, they're dying en masse.

Their absence is bad news for the $15 billion worth of produce nationwide that needs honeybees for pollination. Don Jackson, a seasonal apiary, or beehive, inspector for the state, said he has seen the figure for bee-dependent food as high as $100 billion.

"When you consider people's backyard apple trees and their gardens with squash and raspberries and things, that's not counted in that [$15 billion] figure," he said.

Here in the Northland, a bee die off could potentially cloud the outlook for the handful of honey producers, to say nothing of area flower gardens, orchards and berry patches now in full harvest mode.

"Some ... people have said, 'Well, maybe I just won't have any apples this year,' " said John Skalko, a beekeeper in Esko who lost nearly half his colonies over the winter. "People don't realize how important bees are for all kinds of crops. There's not much left in nature anymore. It's all dependent on the bees."

For now, the USDA is calling the bee disappearances Colony Collapse Disorder. Jackson, of Pequot Lakes, points of that it's not a disease in itself, but rather a term for symptoms without an identified cause.

"When it got us was probably in February," said Bruce Wilmer, who has 7,000 hives at his Wilmer Honey Farm in Warroad. "They just dwindled down. They were just very sick-looking for about two months."

Last winter must have also been when 10 of Skalko's 23 hives sputtered out. Opening the hives, which usually contain between 60,000 and 80,000 bees, in the springtime revealed an unpleasant surprise.

"There was an ample load of honey," he said. "Just no bees."

Skalko has kept bees for about 10 years.

"This is the first time I've ever lost this many," he said.

Colony Collapse Disorder alarms Northland honey producers on several fronts.

First, if it's something -- pesticides, household chemical buildup or some other toxin -- in the pollen bees are consuming, that has dire implications higher up the food chain.

"My family eats that honey, and if my family's going to eat it, I want to make sure it's good," Skalko said. "And for my customers, my good name is attached."

Then there's the business aspect. Reordering bees to replace those that disappear is expensive and impractical.

"I'm concerned," Menefee said. "It's my livelihood."

Of course, there have been previous crises in the honeybee industry. In 1980, for instance, honeybee populations took a nosedive. But in that case, there was a clear culprit: a parasite known as the tracheal mite.

For now, no one is sure what's causing Colony Collapse Disorder.

"If you don't know what the problem is, how can you combat it?" asked Menefee.

Theories range from new pesticides and toxin buildup to undetected parasites and previously unseen viruses.

An Internet rumor that cell phones or cell phone towers are causing the die-off is "absolute baloney," according to Jackson. He thinks it could be resurgent pests, an undetected virus, impure pollen from bioengineered crops -- or perhaps all three, or perhaps none of them.

The USDA's four main potential culprits are pathogens, bee pests, environmental stresses and pesticides.

Wilmer lays most of the blame on pesticides.

"For every weed, for every bug, there is a spray, and the bees have to compete with that," Wilmer said. "I really do think it has a lot to do with insecticides."

The strange behavior of his bees still makes Menefee scratch his head, but he thinks human interference might be the root of the problem.

"The malady can probably come back to the way we're doing things. We're a complete monoculture. Everyone wants a green lawn. They don't want a dandelion," he said. "Things are kind of riding along on a narrow keel. Everybody's wondering 'Is this a sign of things to come?' "

Whatever's causing Colony Collapse Disorder, it's the latest addition to a heap of trouble facing beekeepers.

In 2007, a National Academy of Sciences committee concluded a two-year study that determined the honeybee industry was "in crisis." Parasitic mites caused losses of up to 100 percent in some areas in the winters of 1995 and 2000, Africanized honeybees are polluting "clean" European honeybee bloodlines and a major bacterial disease has developed a resistance to prevailing antibiotics.

Here in the Northland, two dry summers in a row are taxing honeybees by making life harder for their blossoming food sources.

"It's a whole new era for us in trying to keep these things alive," Wilmer said. "It didn't used to take this degree of management to keep them healthy."

So far, Colony Collapse Disorder hasn't brought much misfortune to Northland agriculture.

Deb Shubat, a market gardener and owner of Shubat's Fruits in Duluth, keeps two hives on her property, so there was no shortage of activity around her apple blossoms this spring.

The raspberry blossoms aren't lonely at the Bayfield Apple Company, an orchard and berry farm in Bayfield, the apple and berry capital of the western Lake Superior region.

"We're full of bees this year, as every year," said company owner Einar Olsen.

This summer, Menefee's bees are doing fine. His queen bees are laying up to 1,500 eggs a day, ensuring there are plenty of honeybees to drift across the fields of clover and alfalfa and through the stands of basswood that provide the pollen for their honey.

But Menefee isn't breathing any sighs of relief.

"Come next fall if we hit this cycle again, I don't know," he said. "I don't know what's going to happen."

Will Ashenmacher can be reached at (218) 723-5218 or washenmacher@ duluthnews.com