HERALD, Calif. — Third-generation beekeeper Roscoe Hall spent the past year fretting over a disease that's inexplicably caused thousands of his industrious insects to abandon their colonies.

Now, entire hives are disappearing, too.

In the long, flat valley where the nation's almonds grow, bee thieves are striking hard this winter, nabbing increasingly valuable hives from farmers' fields where bees are used to pollinate blossoming nut trees.

A few weeks ago, 180 of Hall's hives were lifted over a period of days, a bit of banditry he estimates cost him nearly $70,000 in lost bees, pollination fees and honey production.

"If a man doesn't have his bees under lock and key these days, he's going to pay for it," Hall said as he opened one of his remaining hives to reveal thousands of amber-colored bees busy in the honeycomb. "Even then they'll find a way of breaking the lock."

Each year, thousands of keepers haul their bees to California during bloom season to work with farmers who depend on the insects for more bountiful almond crops, larger blueberries and perfect watermelons.

But a bee shortage — largely the result of a puzzling ailment called Colony Collapse Disorder that causes adult bees to forsake their broods — has pushed the cost of renting a hive this year to $200 in some places, up from about $55 four years ago.

IT'S THE BUZZ

As the price of pollination soars, each hive becomes a sitting gold mine, sheriff's deputies say. Skilled criminals simply dump the colony into a new container, and rent the bees to farmers as their own, pocketing the fee they're paid for pollination.

"Just from the buzz that's out there, our detectives are thinking hive thefts are increasing," said Bill Yoshimoto, project director for the Central Valley-based Agricultural Crime Technology Information and Operations Network. "If there's even a further shortage because of bee thefts, that's a problem for everyone."

The network — a coalition of agricultural commissioners, district attorneys and sheriff's departments — has been investigating the thefts, which Yoshimoto said have become more prevalent over the past two months.

Such thievery so far hasn't affected the value of the state's almond industry, which fetched a record crop worth more than $1.9 billion in 2006, the last year for which figures were available, said Richard Waycott, president of the California Almond Board.

But the hive heists have set keepers in California back as much as $330,000 in the past year and a half, including the cost of the hives, the bees, and the money they would have earned from pollination and honey-making, according to local sheriff's departments.

Stolen hives are a small but perennial problem at bloom season in Florida and Montana, too. Florida agriculture crime officials say 200 hives were stolen last year as the bees fed on Brazilian pepper weeds near LaBelle and West Palm, for a total loss of about $60,000 including fees.

Three weeks ago, thieves snatched 72 hives from an orchard near Manteca, Calif., about 15 miles south of Stockton.

NIGHT STALKERS

In nearby Chowchilla, the district attorney is looking into a case reported by a farmer's mother, who surprised a would-be bee thief sneaking around their orchard after dark.

"She spotted his minivan at the side gate and asked what the devil he was doing there," said Erica Stuart, spokeswoman for the Madera County Sheriff. "He told her he was a beekeeper from San Francisco and just happened to be 150 miles away in Chowchilla, checking on his hives."

Honeybees thrive in the warm, winter feeding grounds of California, and almond farms of all sizes use the pollinators' services to grow about 80 percent of the world's almonds. In pollination, bees take pollen from one flower to another flower to fertilize the seed, which gives the plant a signal to build a fruit around the seed.

Still, the risk of getting stung keeps most novice burglars from filching bee hives, authorities say. Keepers typically stack their hives two-tall on wooden pallets, which bees included, can weigh up to 500 pounds and require a forklift to move.

"A hive isn't something you just throw into your trunk," said Orin Johnson, a former president of the California Beekeeper's Association, "Generally it's someone with knowledge, experience and equipment who thinks 'Go-llee, it's just easier to go and load someone else's hives up than it is to make my own.' "

BOXES ARE BRANDED

Beekeepers try to fend off thieves by burning both the wooden boxes where the bees form their colonies and the frames where they build their honeycombs with individual brand numbers they're issued by the state.

Others, like Johnson, are going high-tech, buying traceable microchips that can be implanted into the boxes.

Global positioning technology sends an alert to the owners once the hives are on the move, but some keepers complain it's too late to find them by then since the chips can only be traced at close range.

Johnson lost 70 hives to a bandit a few years ago, but authorities eventually found them lying in an orchard in the next county. After placing a lien on the thief's property, Johnson recovered about $5,000, but he said he had to spend extra money nursing his sick bees back to health and replacing several queens the thief let die.

Hall, who earns 80 percent of his annual income renting bees during the almond bloom, said he was too busy working to worry about buying fancy security devices to guard his hives.

As he scrambles to meet farmers' orders, he's stashed his remaining colonies in a field of wild mustard in Herald, a tiny farm town 30 miles from Sacramento.

Thousands of scouts — mostly female workers — made a light hum on a recent afternoon as they flew into the boxes packing gobs of brilliant yellow pollen on their hind legs to feed their brood.

"It hurts us, don't get me wrong," Hall said. "We'll get everything made back up and go again. These little animals keep going, and we do, too."