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Amy Colvin/Contributed photo

Commercial cherry harvesters have 'zero tolerance' for fruit flies


By Nino Paoli

Published on 8/2/23

COVE — Before commercial cherries grown in Cove are exported to countries around the world, they must first pass the fruit fly test.

Data collected by the past Union County fruit fly inspector suggest an increased presence of fruit flies on commercial and privately owned cherry orchards in the area. In response to the trend, and without a fruit fly inspector amid the 2023 cherry season, Cove commercial growers encourage the community to routinely check for and spray their trees.

“We can spray all our stuff, but if, say the orchard next door, the neighbor next door, isn’t spraying and those fruit flies come in on something ... if we get it in the fruit, it contaminates the (harvest) load,” said Amy Colvin, on-site manager for Monson Fruits, a fruit growing and packaging company that has a 100-acre orchard in Cove and owns Cove Cherries LLC.

The western cherry fruit fly, native to North America, was first reported attacking commercial cherry trees in the Pacific Northwest in the early 1900s, according to the Washington State University tree fruit website.

Now, the fruit fly is the main biological pest in Cove’s commercial orchards, which export to a handful of Pacific Rim countries, including Australia, Canada and China.

Rebecca Singer, the past Union County fruit fly inspector, placed fruit fly traps in seven cherry orchards — both commercial and privately owned — in Cove during previous years. She recorded a steady increase in flies per trap from 2020 to 2022.

When adult flies emerge — usually in May, about five weeks before the cherry harvest — they do all the usual fly things. They mate, and females lay their eggs in the ripening fruit, according to the WSU website. After about a week, the larvae hatch from the eggs and feed on the cherry from the inside.

Darrin Walenta, agronomist at the Oregon State University Extension Office, said cherry growers have “zero tolerance” when it comes to fruit flies in their crops, as other countries will not take the cherries if there is a chance fruit fly eggs or larvae will travel in the harvest load.

“Other countries that grow cherries and that we export to want to ensure that we’re not exporting pest problems to them,” said Mike Preacher, vice president of marketing for Domex Superfresh Growers of Yakima, Washington, which ships cherries for Cove Cherries LLC.

A full harvest load is 120 bins at 300 pounds of fruit per bin, Colvin said.


Read the full article on The Observer's website here.

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