With a workforce of billions, they contribute more than $15bn (£9bn) to the US economy each year - but as populations decline, can the humble honeybee be saved?

A giant inflatable corn on the cob towers over the hundreds of stalls at the Wisconsin State Fair. Food is the main draw, in what's a showcase for local produce. The unhealthier, it seems, the better.

Families can be seen piling in mouthfuls of everything from sausages dripping in fat, to cheese curds, and sticky cherry pie. Some of the more unusual delicacies include deep-fried cookies and fish and chips on a stick.

Standing on the stage under the tent at the Wisconsin Food Pavilion are two immaculately dressed young women wearing crowns on their heads and sporting silk sashes, the kind usually seen at beauty pageants.

Image caption Anna Kettlewell (right) and Lois Hoftiezer Graf (second from right) join two other former Wisconsin Honey Queens in promoting the honey industry

They are former Wisconsin "Honey Queens" - statewide ambassadors for the beekeeping and honey industry. Their job is to travel throughout the state, speaking about honeybees at schools, festivals and farmers' markets.

Anna Kettlewell held the title in 1998. She is on stage showing off the benefits of the sticky stuff in a cooking demonstration, as she makes an ice-cream syrup.

But she is also here to educate people about the wider importance of the honeybee, which is the official state insect of Wisconsin.

"Honeybees are absolutely vital for the nation's food supply. One third of our diet is dependent on the honeybee," she says, reciting her Honey Queen talking points.

"The beekeeping industry in Wisconsin is very important for our cranberry industry. Honeybees are responsible for pollinating our cranberry crops in the state, which is our state fruit."

Another Wisconsin Honey Queen, 60-year-old Lois Hoftiezer Graf, is handing out samples of the different varieties of honey made in the state. She dishes out spoonfuls dressed in the immaculately preserved sash she was given when she took the title in 1972.

"I think the marketing has improved quite a lot," says Lois of the changes in the honey industry since then. "The other thing that has changed in our culture, is we're much more interested in natural and organic foods."

Image caption The honeybee is important to both the Wisconsin and the US economies

But as tastes have changed, so too have the fortunes of the honeybee, which has seen its population decline across the United States.

In the past 60 years the number of honeybee colonies has fallen from six million beehives in 1947, to just 2.5 million today, according to the White House.

The honeybee's decline

In October 2006, some beekeepers began reporting losses of 30-90% of their hives. While colony losses are not unexpected, especially over the winter, this magnitude of losses was unusually high

In 1995-96, Pennsylvania beekeepers lost 53% of their colonies without a specific identifiable cause

In 1903, in the Cache Valley in Utah, 2,000 colonies were lost to an unknown "disappearing disease" after a "hard winter and a cold spring"

Source: US Department of Agriculture

This decline, the White House says, could pose a real threat to US agriculture, because of the role the honeybee plays in the pollination of fruit, nuts and vegetables.

It might be a tiny little insect, but one mouthful in three, directly or indirectly, benefits from honeybee pollination, according to the US Department of Agriculture. Honeybees enable the production of at least 90 commercially grown crops in the US.

In a sign of how seriously this is being taken, in June, President Obama launched a taskforce to protect the honeybee. The White House is investing $50m into research and action to stem the decline, improve habitats and promote better education around the issue.

It is welcome news for Ryan Stern, a beekeeper who runs Concord Farms in Sullivan, Wisconsin. His business began as a few hives, and is now a large, commercial operation.

"I was growing in [terms of] numbers of bee hives and I was starting to not be able to manage those bee hives and work full-time correctly, and I had to make a choice of what I wanted to do.

"I really enjoy working with the bees every day, it's nice being out in the sun working with them. Being stung is not the most enjoyable thing but every job has its downfalls."

Image caption Ryan Stern's business began as just a few hives but has grown over the years

Ryan pulls out a frame from one of his 48 hives, to reveal a swarm of bees, navigating the honeycomb furiously. As he scratches a small section of the frame, a large, sticky drop of honey falls from it.

This is Ryan's livelihood, but harsh winters, and pesticides have made it tough for him to keep all his bees alive.

"If you can keep your bees alive you can make money, but keeping bees alive definitely costs a lot of money by itself.

"Between the pests, the disease, nutrition, lack of forage, it's definitely just a hard environment to keep them alive in, and unfortunately with genetically modified plants some of the pollens and stuff off of these crops you don't really want to get into your bee hives."

Some years Ryan says he measures success by how healthy his bees are, not by what is produced.

Image caption Ryan Stern says keeping bees alive is a costly business

The White House has named Wisconsin as one of five states where farmers and ranchers will be given extra funding to continue their work in establishing new habitats for honeybee populations, but Ryan is not yet sure if his farm will reap the benefits of that.

Still, he thinks President Obama's action on the bee industry is a good move, and he says everyone, even those who aren't in agriculture, needs to focus more on the role the honeybee plays.

"You don't have to have 100 acres to help with the issue. Every lawn, every yard can help. It's important because it will affect the food supply everywhere.

"If there's a shortage in one area, it's a global economy, so it's going to change food prices all across the world."

For more on this story, listen to Business Daily on BBC World Service at 08:30 BST (07:30 GMT) on Tuesday, 2 September.