Remember the junior high joke: "What do bees make?"

Answer: "Honey."

Jokester, indignant: "Don't call me honey."

Yes, the guy on the street usually thinks of bees as mere honey producers -- and picnic pests.

But, according to the U.S. Department of Agriculture, bee pollination is crucial for the production of one-third of the human diet.

Bee pollination also accounts for $15 billion in crop value, especially for specialty crops such as almonds and other nuts, berries, fruits and vegetables.

Recently, however, bees have been challenged by a number of threats, including pesticides, mites, viruses, bacteria, fungi -- and the well-publicized phenomenon of Colony Collapse Disorder, in which bees leave their hive and never return.

The cause of the syndrome is not fully understood, though some authorities blame environmental stresses, mites and viruses. Such disappearances have occurred throughout history, but the term Colony Collapse Disorder, or CCD, was first applied after a drastic rise in the number of incidents in 2006.

With summer and honey production now drawing to a close, Lee Miller, president of the Pennsylvania Beekeepers Association, said varied reports about the health of bees across the state.

Mr. Miller recently attended Ag Progress Days -- the state's largest outdoor agricultural exposition -- at State College, where he talked to beekeepers from all over Pennsylvania. "Some, including myself, are doing better than last year, while others aren't doing as well," he said.

Edward Hamilton, of Finleyville, has been keeping bees for 40 years and had, at one time, as many as 187 hives. Currently, he cares for about 30.

"One month it seems the bees are doing fine, the next month there's hardly any bees left, which is a sign of CCD," he said. "Even so, CCD is not as bad as the mite problem."

In the past, Mr. Hamilton harvested as much as five or six tons of honey in one year. The past three years, however, he's not been able to harvest any for himself because production has been low and he had to keep what little there was in the hive to help the bees survive the winter.

This year, however, his bees seem to be doing better, and he expects to harvest close to 350 pounds of honey.

"Years ago, you could just leave bees alone, and each hive would produce 40 to 60 pounds twice a year," he said. "Now, you have to give them antibiotics and treat them for mites."

About 20 years ago, mites infected his hives and seriously reduced his colonies.

"I've never been able to build them back up beyond 40 hives since then,'' he said.

In Upper St. Clair, Franny Brown has been keeping bees for the past five years, starting with two hives. She has lost some hives but is not certain why. To replace them, she managed to bring in four swarms or colonies found in the wild.

"This year, my bees are doing really well," she said. "I inspect the hives regularly, and what I started out with in the spring I still have."

According to Ian Hough, owner of Bee Control in Ross, bees in the wild my be doing a little better than their cultivated cousins.

"In the last two years, I've gotten a large number of calls from people regarding swarms of bees in hollow trees or houses," he said. "Whenever I can, I try to transfer these nuisance or unwanted bees to area beekeepers."

Bethel Park resident Tom Corbett is new to beekeeping, starting with two hives in April and doubling his number of hives by adding two additional swarms in May.

"So far, when I look in the hives to see how well the bees are doing by building cones, storing pollen and increasing their population, two hives are very healthy and productive while two seem to be only marginal."

In Hopewell, 15-year veteran beekeeper Wayne Berg is experiencing a year different from most. Although he said his 20 hives contained numerous bees, honey production is markedly down.

"In an average year my bees produce 1,700 to 2,000 pounds of honey," he said. "This year, after I leave enough for the bees to get over winter, I'll probably harvest only 100 pounds for myself."

Mr. Berg believes that the wet spring had a lot to do with his diminished honey production because "rain washes the nectar out of the flowers."

He is hoping for a better fall production with the flowering of plants such as goldenrod and Japanese knot wood.

Across the region, the state, the nation and the globe, the ongoing health of bees is still a vital concern.

"We think the key to keeping bees healthy is better nutrition, monitoring for mites and raising bees genetically tolerant or resistant to diseases and mites," Mr. Miller said.