Bay Area towns quarantined over invasive flies

California is going to war with invasive flies and placing portions of the state under quarantine — again. 

The Oriental fruit fly, or Bactrocera dorsalis, is a voracious pest that can destroy up to 400 different types of fruits and vegetables, including some of California’s most valuable crops, according to the U.S. Department of Agriculture. County maps show that some 112 square miles of Santa Clara County are now under quarantine due to the invasive brown-and-white fly, an area encompassing Sunnyvale, Santa Clara and Cupertino.  

Though it’s unclear when and how the pests arrived, the Department of Agriculture wrote that they usually infiltrate California via uninspected produce. Officials declined to provide details on the quarantine to SFGATE, but when the Tau fruit fly prompted a quarantine in the Stevenson Ranch area in July, residents were urged to not move produce from their property. 

According to a Sept. 5 news release, the tropical fly, which is originally from southern Asia, was discovered in Santa Clara County in August 2023. Now, the California Department of Food and Agriculture is spraying “splotches of bait” on trees and utility poles throughout portions of Santa Clara, Sunnyvale, Cupertino and San Jose to lure and kill male flies using an “attractant technique,” the release reads. CDFA employees will continue to use pressurized spray guns to shoot this concoction of methyl eugenol and Spinosad 10 feet in the air every few weeks.  

This isn’t the first time the Bay Area tech capital has gone to war with the Oriental fruit fly. Per the Agriculture Department’s release, this type of fly has been detected and eradicated in Santa Clara County multiple times in the last decade. In fact, officials confirmed to SFGATE that it was discovered in the region just last year. 

According to an Aug. 31 news release from the Santa Clara County District Attorney’s Office, two San Jose residents were recently accused of smuggling langsat — which the release described as a “dangerous fruit” – into the country and shipping it addressed to Tracy’s Gift Shop, a small storefront located in a South Bay strip mall. Two hundred pounds of the yellow, grapelike clusters were discovered and labeled as dried fish, coffee or tea on the packaging to avoid inspection, the release continues. When officials seized and tested fruit sold by one of the defendants, they discovered that it was “heavily infested” with fruit fly larvae. Santa Clara County press representatives told SFGATE that the quarantine is unrelated to the defendants’ recent arrests.  

“This is serious and reckless behavior. If they spread, these flies can destroy crops,” said District Attorney Jeff Rosen in the Aug. 31 release. “This County’s farms and everybody’s food prices are at stake.” 

“These infestations are the result of contraband fruit smuggled into California,” officials in the Sept. 5 release wrote. “We ask all Californians not to bring fruit or vegetables back from your travels.” 

Anyone who suspects infected produce should contact the County of Santa Clara Division of Agriculture at scc.agriculture@cep.sccgov.org or 408-918-4600.

Sep 5, 2023|Updated Sep 5, 2023 5:44 p.m.