MACHIAS — A tiny, spotted-wing Asian fruit fly has made its way from the West Coast to the blueberry barrens and cranberry bogs of Down East Maine, where growers fear it could target their crops in the upcoming 2012 growing season.

The Japanese pest lays its eggs in soft berries, which destroy the fruit. There are pesticides that are effective, but spraying is both costly and time-consuming, said David Yarborough, the University of Maine Cooperative Extension’s blueberry expert.

“It can be quite devastating,” said Yarborough. “In 2010, we found it in one trap we set. Last year we found it everywhere we looked. It has the potential of being a major pest, as it is very prolific and lays thousands of eggs in soft fruit, including blueberries and cranberries.”

He said the pest destroyed the raspberry crop in Connecticut last year.

The Extension Service will step up its monitoring program to track the spread of the fruit fly, Yarborough said.

Following an average harvest in 2011, growers don’t need any new threats to this year’s crop.

Last year’s harvest is estimated at 80 to 85 million pounds, which is about average, Yarborough said. Growers received higher prices — about 80 cents a pound — than they did in 2010, benefiting from a poor harvest in Quebec.