CHERRYFIELD — Maine could yield an above-average harvest of wild blueberries this year, according to both the state’s leading expert on low-bush wild blueberries and to officials with a leading blueberry producer Down East.

The harvest is about to begin, and the barrens have begun turning blue as the berries ripen.

University of Maine horticulture professor David Yarborough, whose specialty is wild blueberries, was in Washington County on Wednesday, working with teams harvesting small plots of blueberries as part of a research project.

Yarborough pointed out that heavy rains soaked Washington County — the state’s leading producer of wild blueberries — fortuitously last week. “The berries seem to be really huge,” he said. “It’s amazing.”

This year’s harvest “might be better than average,” he suggested.

Two officials with Milbridge-based Jasper Wyman and Sons, which has more than 8,000 acres in blueberry production, likewise had a generally upbeat outlook for this year’s harvest.

“Everybody’s saying there’s going to be a good crop out there,” said Ellen Rossi, director of operations at Wyman’s processing plant in Cherryfield.

“This year’s crop could be above average,” company President Edward Flanagan, speaking from the company’s headquarters in Topsfield, Mass., said Tuesday.

However, Flanagan added “one great big caveat:” Growers are concerned about the risk to the harvest from the spotted wing drosophila, a fruit fly that damages blueberries.

Despite favorable growing conditions this year, the threat from the pest remains very real.

In a University of Maine Cooperative Extension blog for blueberry producers, Yarborough said the insect has been captured in traps in all blueberry growing regions, “indicating that reproduction is occurring and fruit infestation is taking place.”

The flies puncture a blueberry and lay eggs, Yarborough explained. Then the hatched larvae consume the fruit. A new generation can be produced in as little as 10 to 14 days, with each insect laying 300 eggs.

Yarborough recalled a grower last year who lost 2,000 pounds of blueberries on 1 acre because of damage caused by the fly.

“It’s a real problem,” he said, but growers can set traps to monitor for the pest, and they can treat the bushes with insecticides to control the fly. The crop must be protected from the insect, he said. Growers also may begin the harvest early to contain damage.

His company was “monitoring very carefully” for the insect, said Flanagan. “We haven’t seen them in a serious way, but that doesn’t mean we’re not going to.”

Nevertheless, Yarborough was optimistic about the pending harvest.

“The berries look very good,” he said. They have good size, thanks to good pollination earlier and plenty of moisture. The two factors “are key to good-quality, large blueberries,” said Yarborough, who was collecting blueberries from sites in Washington and Hancock counties this week as part of the research project. The $1 million, four-year study, now in its final year, will compare organic growing methods as well as varying levels of management practices and look at impacts on the environment.

“Growing weather has been pretty good,” said Flanagan, whose company is the leading marketer of U.S. blueberries.

“Certainly, we don’t lack for water,” he added. “That’s been good.” Blueberries are 89 percent water, he said, “so you’ve got to have water.”

Maine’s wild blueberry harvest averages 86 million pounds annually, according to Yarborough, who said growers were expected to begin harvesting operations Saturday or possibly Monday.

Last year’s production was 91.1 million pounds, which fetched an average price of 76 cents per pound, or a total of $69.2 million. In the previous five years, production ranged from 76.3 million to 89.9 million pounds, and average prices ranged from 35 cents to $1.07 per pound.

Washington County is Maine’s leading producer of wild blueberries, contributing to about 80 percent of the state’s production, according to Yarborough. Hancock County is second.