WENATCHEE — Small cherries left on the tree this year could set up conditions for a serious fruit fly outbreak in commercial orchards next year.

That’s a serious matter because California and some other states and countries that Washington ships to have zero tolerance restrictions on fruit fly larva. A single larvae found in a box of cherries during fruit inspections can result in restrictions that would keep an entire warehouse from shipping to or through that state or country for the season. Most export cherries are shipped through California so that could result in a huge loss of income, said Len Pugsley, a fieldman for McDougall & Sons and a director of the Chelan-Douglas County Horticultural Pest and Disease Control Board.

“The most important spray a grower can put on for next year is the postharvest spray this year,” said Pugsley. Most commercial growers know the importance of preventative and postharvest sprays for fruit fly, he said, but some growers have been cutting back on programs because of tough economic conditions. Many trees with heavy crops of small fruit won’t be picked this year due to low prices for small cherries. Left unsprayed, Pugsley said, those cherries will fall to the ground and set up ideal breeding conditions for serious problems with the pest next year.

“A lot of growers may have forgotten how bad fruit fly can be. If nothing is done, we could have fruit fly raising its head all over the country,” he said.

Tests show that a single postharvest spray of the chemical dimethoate applied within a week of normal harvest period can kill the larvae.

Local residents with backyard trees can control the problem by stripping the entire tree of fruit. If the cherries are unwanted, they can be put in a tied black plastic bag and left in the sun for a few days and then disposed in the trash, Pugsley said. For more information, call the pest board at 667-6677 or check out their web site: www.co.chelan.wa.us/pc/pc_main.htm.