Spotted wing drosophila raising cain in California

A fruit fly that made its first California appearance four years ago in Watsonville  - spotted wing drosophila - can be managed with three basic common-sense techniques.

"It's going to come down to trapping, monitoring and good sanitation," Mark Bolda, University of California Cooperative Extension farm adviser in Santa Cruz, Monterey and San Benito counties, told a group of growers in January, according to an article in the Santa Cruz Sentinel.

"Most of the industry is in this room right now," the story quotes Bolda. "That's why it's important to work together. You can't leave discarded fruit in the fields anymore. Neither can your neighbors. It's going to be a breeding ground for flies."

Last July, Bolda wrote in his Strawberries and Caneberries Blog that spotted wing drosophila had infested cherries, raspberries, blackberries, blueberries and strawberries in California.

"It has been found in many (I think the number was 21) counties across California, as well as several other states," Bolda wrote.

However, he told farmers last month he is optimistic that growers and researchers are headed in the right direction.

"I think the worst of it is behind us," he said. "Really, it's standard pest management. We just got caught by surprise, initially. We have much more work to do. We still haven't gotten really clear results."

At Grape Day this week in Lodi, the opening speaker, UCCE farm advisor Paul Verdegaal, focused on vine mealybug and spotted wing drosophila, reported the Lodi News-Sentinel.

He said spotted wing drosophila resembles the common vinegar fly, which only attacks rotted fruit, but will also lay eggs in healthy fruit with soft flesh, such as grapes, cherries and strawberries.

Reporter Jordan Guinn wrote that there are still many unanswered questions about the pest, but scientists know one thing for sure: It's spreading rapidly. The pest came from Japan and is now a regular resident in orchards and vineyards in California, Oregon and Washington.

Up-to-date information on spotted wing drosophila can be found on Bolda's blog.

Detailed background information about spotted wing drosophila is available on the UC Integrated Pest Management Web site.

Spotted wing drosophila.

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