A portion of San Diego County has been placed under quarantine for the Mexican fruit fly following the detection of six flies and one larva in and around the unincorporated area of Valley Center.  

The quarantine area in San Diego County measures 77 square miles, bordered on the north by Wilderness Gardens Preserve; on the south by the Lake Wohlford Park; on the west by Moosa Canyon; and on the east by Hellhole Canyon Preserve. 

As part of the eradication effort, approximately 250,000 sterile males will be released per square mile per week in an area of 43 square miles around the infestation.  

In addition, properties within 200 meters of detections are being treated with an organic formulation of Spinosad, which originates from naturally-occurring bacteria, in order to remove any live fruit flies and reduce the density of the population.  

Fruit will also be removed within 100 meters of properties with larval detections and/or female fly detections.

The quarantine will affect any growers, wholesalers, and retailers of host fruit in the area as well as nurseries with Mexican fruit fly host plants. 

Local residents and home gardeners affected by the quarantine should consume homegrown produce on-site, to include canning, freezing or juicing and should not move host items from their property.  

These actions protect against the spread of the infestation to nearby regions which may affect California’s food supply and our backyard gardens and landscapes.

The eradication approach used in the Valley Center area of San Diego County is the standard program used by CDFA and it is the safest and most effective and efficient response program available.

The Mexican fruit fly can lay its eggs in and infest more than 50 types of fruits and vegetables, severely impacting California agricultural exports and backyard gardens alike. 

The United States Department of Agriculture (USDA), the San Diego County Agricultural Commissioner, and the California Department of Food and Agriculture (CDFA) are working collaboratively on this project.

 A link to the quarantine map may be found here: www.cdfa.ca.gov/plant/mexfly/regulation.html.