Over-wintering fly threatens B.C. cherry crops

Okanagan fruit growers are calling the havoc wreaked by a fly that destroyed an estimated $2 million worth of B.C. cherries last summer the mad cow disease of the cherry industry, and many fear the damage could be worse next year.

"We're now dealing with probably the pest that's had the greatest impact on production of cherries and soft fruit in the history of this business," says Greg Norton, who runs a family orchard in Oliver, B.C., in the Okanagan Valley.

The fly, the spotted wing drosophila, hails from Japan and was first seen in B.C.  in 2009 in Kelowna. The vinegar fly lays its eggs in soft fruit, including peaches and cherries.

Norton says growers thought the fly wouldn't survive a Canadian winter, but the pest returned in even greater numbers in 2010.

"We were hoping that this thing would die off," Norton said. "They're supposed to die after minus 2.2 degrees Celsius. Obviously, that didn't happen because we had an over-wintering population."

Norton says there's no one clear way to get rid of the pest, and the fly's reach is worse than the industry ever imagined.

"We got it here through the fruit distribution, probably out of California," he said. "But we're not alone. It's spread to Europe, every jurisdiction in North America has it now. So, it's very, very rapid spreading. "