Late in 2009 it was reported that a new species of Vinegar Fly (Drosophila) was attacking sound fruit. This is unusual as Drosophila usually will attack rotting fruit. It had not been observed in vineyards to date, but the concern was vineyards near cherry orchards.

I began trapping the edges of a number of vineyards I consult with in San Benito County, that are adjacent to cherries. I observed , and trapped SWD in both the cherries and grapes. However, I did not find that SWD were attacking sound fruit. With the large amount of rainfall we dealt with on October 15, 2009 , conditions were perfect for bunch rot. Even with this scenario we were lucky enough to avoid heavy rot loss (Botrytis) even where we found SWD.

According to the UCANR site : “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.

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

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