Oriental fruit fly quarantine in effect for parts of 2 Bay Area counties

California Department of Food and Agriculture has issued a quarantine for an invasive pest identified by the U.S. Department of Agriculture as the Oriental fruit fly for parts of Santa Clara and Contra Costa counties, officials announced Tuesday. 

In Contra Costa County the invasive species has been detected near the cities of Brentwood and Oakley. The quarantine zone covers 99 square miles. The quarantine's border to the north is along the San Joaquin River; on the south it is bordered by Marsh Creek State Park; along the west, the border is Black Diamond Mines Regional Preserve. On the east the border is along the Old River. 

For Santa Clara County, detections were made in Santa Clara and Sunnyvale. The quarantine zone there covers 112 square miles. The border to the north is along Coyote Creek; on the south it is bordered by Saratoga; on the west by Mountain View; and on the east by Alum Rock. 

You can see a map of the quarantine zone here

"Invasive fruit flies are serious pests for California’s orchards and backyard gardens," said CDFA Secretary Karen Ross. "These recent detections remind us that we need to remain vigilant in protecting our food supply and natural resources. The stakes are enormous, and not just in California. A new report from the United Nations notes that invasive species management costs hundreds of billions of dollars each year around the world. We’re all in this together as we work to reduce this impact. "

State agricultural officials say the pest targets more than 230 different types of fruits, vegetables and other plants. This includes crops grown in California such as; tomatoes, peppers, grapes, stone fruits, citrus, dates and avocados. 

Officials say the damage is done when the female fly lays her eggs inside the fruit. Once the maggots hatch, they make the fruit unfit for consumption. 

Residents in the quarantine zones are advised to not move homegrown fruits and vegetables from their areas. 

"However, they may be consumed or processed (i.e., juiced, frozen, or cooked on the property where they were picked, or disposed of by double bagging and placing in the regular trash, not green waste," a news release from CDFA stated. 

There are efforts underway to mitigate the spread of this species. Agricultural workers are spraying an attractant mixed with a small amount of pesticide in affected areas. Male fruit flies are attracted to the solution and are killed after consumption, according to officials. 

Perhaps surprisingly, officials say the flies are initially found in urban and suburban communities. They often find their way into communities through "hitchhiking" in fruits and vegetables brought back illegally by travelers from other regions. Another way the species invades is when they are brought into the country from other regions through packages of home-grown produce. 

Officials say the fly is widespread in southern Asia and neighboring areas including Sri Lanka and Thailand. Infestations have occurred in Africa and Hawaii. 

Last week officials in Santa Clara County warned that nine Oriental fruit flies were detected in the county. A farmer's market in Saratoga was affected. 

Residents with questions about the project may call CDFA’s Pest Hotline at 1-800-491-1899. Additional information may be found here: www.cdfa.ca.gov/plant/off.