Honeybees don't just produce honey: The hard-working insect is also fundamental to the world's food supply.

One-third of the food we eat depends on insect pollination, mostly by honeybees that are raised and managed by beekeepers.

The value of insect pollinators on world agricultural production, which accounts for their role in producing better quality and quantity of harvests, was estimated at $208 billion in 2005.

That figure does not even include the retail value of what honeybees pollinate — everything from apples and cherries to broccoli and pumpkins — or the honey that bees produce. In the United Kingdom alone, where honeybees contribute an added crop value of about $413 million, the estimated retail value is north of $1 billion.

But the downward spiral of honeybee populations — both wild and captive — has put all of that at risk.

The number of managed colonies is declining nationwide because of new pressures including disease, parasites, and the phenomenon known as colony collapse disorder, when bees inexplicably disappear from their hives. The stresses of being trucked around the country thousands of mile each year to pollinate different orchards has also taken its toll.

Over the last six years, American beekeepers have lost 30% of their hives each winter on average. More specifically, 10 million beehives have been lost at a cost of $200 a hive since 2006, according to the latest report on honeybee health from the United States Department of Agriculture (USDA) and the Environmental Protection Agency. The cost to replace all of those dead hives — a total of $2 billion — falls on the beekeepers.

Although there are many insect pollinators, there is no good replacement for honeybees, which are easy to manage in masses and are unmatched in the variety of crops they can pollinate. Almonds, for example, rely entirely on pollination by honeybees. American farmers use more than half of the country's 2.4 million honeybee colonies each year to pollinate nearly $3 billion of almond crops, mostly in California.

Honeybees as a species are not in danger of disappearing, Kim Kaplan from the USDA says, but what is at risk are large-scale commercial beekeepers and therefore also the farmers who depend on these bees to pollinate their crops.

The income that beekeepers earn from renting their bees to farmers has become increasingly important as farms have expanded in recent decades. If losses stay at the current unsustainable rate, however, more and more beekeepers will have to shut down.

"Imagine you were a dairy farmer and lost 30% of your cows every year — how long would you stay in business?" asks Carlen Jupe, secretary and treasurer of the California State Beekeepers Association. "You can't lose that percentage of livestock and stay in business."

If beekeepers go out of the business, the number of managed colonies will fall even more drastically, meaning farmers will have to pay more for pollination services.

Agricultural economists Daniel Sumner and Hayley Boriss, both of the University of California Davis, note that the decline in California bee populations, coupled with a higher demand for pollination services because of expanding almond crops, has hiked up pollination fees.

"From 2004 to 2006, the price of honeybees to pollinate California almonds has jumped from about $54 per colony to about $136 per colony," the authors wrote in a report from 2006.

If farmers have to pay more for pollination services, it's only a matter of time before consumers start feeling the sting through supermarket prices and empty grocery store shelves.