Dan Kaminski is a gatekeeper to the not-so-secret life of bees.

Kaminski, a Brimfield Township, Ohio, beekeeper, doesn't bother to don a veil or protective clothing when he opens a hive to inspect the goings-on. He wears his regular work clothes, figuring stings just come with the job.

He lifts out a frame crawling with honeybees and points out the oversized queen, the tiny eggs and larger white larvae tucked into cells in the honeycomb, the worker bee carrying grains of yellowish pollen on its sides.

It used to be that Kaminski and his honeybees had a mutually beneficial relationship. He provided them with shelter, flowers to feed on and medication for their ailments. They produced honey he could sell and provided a pollinating workforce he could rent out seasonally to apple growers.

But lately the balance has changed.

His bees are becoming less hardy. They're dying off at a greater rate and producing less honey.

He's had to stop renting out honeybees to apple orchards, because he just doesn't have enough of them.

So now he's slowly selling off his equipment and easing out of the beekeeping business.

"It's a serious problem," he said of the honeybee decline. "And it's not just going to affect my livelihood. It's going to affect (all of) us."

Honeybees are just one of the vast variety of insects and other creatures that pollinate plants, but their role is important. They're generalists, which means they'll pollinate a wide variety of crops throughout the growing season, said James Tew, an entomologist who heads the Honey Bee Laboratory at Ohio State University's Ohio Agricultural Research and Development Center in Wooster Township.

They're "good at a lot of things but not great at anything," Tew said.

Honeybees are also loyal to the plants they feed on, and that makes them valuable to farmers and orchard owners, said Kim Flottum, editor of the Medina-based Bee Culture magazine and author of several beekeeping guides.

Flottum refers to that loyalty as flower fidelity. It works this way: When a worker bee leaves a hive in search of food, it will feed on only one type of flower — whichever type it tastes first on that trip. Unlike other insects that might go from, say, cucumber blossom to dandelion to squash flower, the honeybee sticks to one thing. So it picks up and deposits only one type of pollen, making honeybees particularly efficient at pollinating crops.

Honeybees are among the pollinators that enable plants to produce much of our food, and food for animals that provide our meat and milk. So the threats to their health are troubling to experts such as Tew and Flottum.

A combination of factors has caused the honeybee population to decline in the last 50 years or so.

One problem is varroa and tracheal mites, two parasites that can kill honeybees and decimate colonies. Another is colony collapse disorder, which quickly kills off bees in large numbers. Flottum believes scientists are close to figuring out the cause of the disorder, which appears to be linked to a combination of nutritional deficiencies, pesticides, viruses and other diseases. But a control for it may be further off, he said.

Even weather can be lethal to bees. An unusually cold or wet growing season or a harsh winter can devastate colonies, Tew and Flottum said.

Humans have played a role in their decline, too. We're using more pesticides and grabbing up more of the bees' natural habitat for development and manicured lawns.

We're farming differently, too. Often big farms specialize in single crops, limiting the diversity of the bees' diet. Flottum likens that to a human eating nothing but fast-food burgers and fries for a month. It won't kill you, he said, but it will take its toll on your health.

Honeybees aren't native to the United States. Flottum said colonists brought them here in the 1600s for their ability to pollinate the apple trees they also brought; for their honey, which the colonists used as a sweetener; and for their wax, used to make candles for light.

For centuries their numbers expanded, but since the late 1950s they've steadily declined, Tew said. Last winter was particularly hard on honeybees; about one-third of managed colonies were lost between October and April, according to an annual survey by the Apiary Inspectors of America and the U.S. Agricultural Research Service.

Honeybees are "just not as vibrant as they were 30 years ago," Tew said. They die more easily when disease or parasites strike, and they're less likely to survive the winters.

As a result, most honeybees in the United States are now dependent on beekeepers, who can nurture them to an extent. Honeybees in the wild are unlikely to survive long, Tew said.

But as the population of honeybees has declined, so has the number of beekeepers.

Kaminski's experience is a case in point: At one time, he said, he had around 250 hives. Now he's down to 40 or so.

With 70 percent to 80 percent of his hives dying off every year, the cost of replacing so many bees has become prohibitive, he said.

Add to that the prevalence of imported honey, and you have little incentive for beekeepers to get into or stay in the business, Kaminski noted.

Advocates and groups such as the Pollinator Partnership are urging people to help honeybees and other pollinating animals by being more mindful of the way they tend their yards.

By using pesticides carefully, planting flowers that bees like and perhaps sacrificing a little bit of lawn for native plants, humans can increase the chances of the bees' survival, they say. And by buying local honey and otherwise supporting beekeepers, people make it easier for those keepers to stay in business and continue to provide the human intervention that honeybees depend on.

Entomologist Tew is hopeful that over time, natural selection will result in stronger bees and less-threatening mites. After all, if the bees die off, their parasites will, too, he noted.

But until then, the honeybees need help to survive, the experts say. And we're the ones who need to give it.