MACHIAS — It’s been a cold, wet and foggy spring along the Down East coastline, which doesn’t bode well for the wild blueberry crop.

Last month, growers trucked in a billion honeybees from as far away as California to pollinate Maine’s 60,000 acres of blueberry barrens. With as many as five hives per acre, there was no shortage of bees, but the critters don’t “work” when its cold and wet, opting instead to hunker down within their hives to stay warm. And, without pollination, there’s no fruit.

“The last few days have been a bust,” said David Yarborough, a blueberry expert with the University of Maine’s Cooperative Extension Service. “But the week before, during the peak bloom, there was perfect weather, off and on. Fields close to the ocean were a bust, but inland they’re a lot further ahead. Overall, I suspect it’s not as bad as it looks.”

Maine’s 2011 wild blueberry harvest weighed in at 83.1 million pounds, according to yield results calculated by the U.S. Department of Agriculture. That was 100,000 pounds more than the 2010 crop. At 85 cents per pound, the 2011 harvest was worth $70.1 million, or 42 percent more than the 2010 crop. Midcoast growers saw lower yields per acre than their Down East counterparts.

Field studies done in Washington County and elsewhere in Maine have shown that yields can be increased by as much as 1,000 pounds per acre for each beehive servicing that acre. Those results presume good weather, adequate soil moisture and good fertilization and pest management.

Yarborough said mild fall and winter weather minimized blueberry winterkill, but that warm weather that he attributes to global warming is making insect pests more of a problem for blueberry growers.

“There is higher pest pressure,” he said Wednesday. “And the mild winter and generally warmer temperatures are contributing to that.”

Nat Lindquist, vice president of operations at Wyman’s of Maine, said on Wednesday that the hives are being pulled this week from barrens owned by Maine’s largest wild blueberry processor.

“We would have loved to have 65 degrees and sunny every day, but that never happens,” he said.