San Diego County Area Quarantined After Mexican Fruit Fly Detection

A 77 square mile portion of San Diego County has been placed under quarantine for the Mexican fruit fly after five flies, including a mated female, were detected in the City of La Mesa. The United States Department of Agriculture, the San Diego County Agricultural Commissioner, and the California Department of Food and Agriculture are coordinating the response. The quarantine area is bordered by the San Diego River to the north, Sweetwater Reservoir to the south, Interstate 15 to the west, and El Cajon to the east.

As part of the eradication effort, sterile male Mexican fruit flies will be released at a rate of approximately 250,000 males per square mile per week within up to 50 square miles surrounding the infestation. When sterile males mate with fertile females, no offspring are produced, reducing the population over time. Properties within 200 meters of detections are treated with an organic Spinosad formulation, and fruit removal occurs within 100 meters of larval or mated female detections. Officials urge residents and travelers to help prevent the spread of invasive pests by following quarantine guidelines and the Don’t Pack a Pest program.