Even though colony collapse disorder, which has devastated commercial bee populations throughout the world, has not appeared in Maine, the University of Maine is playing a key role in studying it.

Maine is one of seven states researching commercial and native bee populations under a federal grant.

At a Stockton Springs organic blueberry farm, professor Frank Drummond has placed 30 experimental hives. With temperatures hitting 90 degrees one day last week, the place was audibly humming. Bees were pouring in and out of the hives, filling the air and seeking a source of pollen.

Drummond, who teaches insect ecology at the Orono university, said the importance of bees to humans cannot be overstated.

“Most of what we eat from the grocery store has been pollinated by bees,” he said. “It is clearly two-thirds of all the crops we eat.”

The disorder, which was at its height in 2007, continues to trouble the country’s 3 million honeybee colonies. Over the past two years, colony collapse disorder has wiped out a third of all commercial U.S. hives.

Whether it involves a virus, parasites, environmental stresses, pollution or a combination of factors, no one is sure. Healthy hives appear to die overnight, leaving agriculture everywhere threatened. Honeybees are vital to agriculture and, in particular, to Maine’s wild blueberry crop.

Maine’s largest blueberry grower, Wyman’s of Maine, pays more than $1 million a year to bee handlers from other states to bring their commercial hives to the blueberry barrens because there are not enough native bees to pollinate all the bushes.

Drummond said there is great concern for Maine’s native bee population. Two species previously found in New England may already be extinct, he said.

“Honeybees are being attacked on all fronts,” Drummond said. “Pests, bacteria, fungus — the damage is massive.”

Colony collapse disorder has been called the canary in the coal mine, and scientists have been looking at a huge decline in native bee populations as an environmental indicator — the first sign that something is wrong.

By collecting pollen, larvae samples and bees themselves, Drummond can help determine to what extent man’s practices have contributed to the disorder and if native bees are being affected.

Maine is one of seven states participating in the U.S. Department of Agriculture study. Minnesota, California, Texas, Louisiana, Florida and Pennsylvania also are involved.

Researchers in each state are conducting similar tests over the next four years. They are starting bee colonies, looking at the rate of collapse and examining the effects of pesticides and the environment, such as harsh winters, on the bees.

Each of the hives has a queen bee supplied from the same genetic pool, Drummond said.

The hives will be sampled each month until winter sets in. “We are looking for a good queen, one that lays a lot of eggs, and we are also looking for symptoms of disease. We are also collecting bees to identify 18 different viruses or mites.”

Maine has 100 species of native bees, Drummond said. “At any one time, there could be seven to 30 kinds of bees in a field,” he said. “But one year there will be an absolute carpet of bees and the next year just a few. We really can’t predict the native bee population year to year.”

Drummond said there are many factors affecting bee populations and insecticides play a large role.

“Potentially, insecticides have a deadly effect on bees but that is variable. Some conventional growers have good bee populations,” he said.

Drummond has also been studying native Maine bee species to see if a native bee population can be managed in commercial hives.

Up on the hill of the blueberry farm, Drummond and two others used smoke to control the honeybees’ behavior and opened each hive. The area is encircled with an electric fence to keep bears away from the hives filled with bees called Italians, a light yellow bee with high honey production.

Beth Choate, a doctoral student, and Jennifer Lund, an entomologist, slide tray after tray of bees out of the hives. They document the health and condition of each hive and collect samples for further testing at the university.

“It’s interesting,” Drummond said. “Bees are often called the angels of agriculture. But these young women, these are the real angels. We have more women agricultural researchers right now than ever in the past. They are young and intelligent and are truly making a difference.”