Category: Tree Fruit

Sacramento, Calif., (September 15, 2017) – A quarantine has been declared due to a Mediterranean fruit fly (Medfly) infestation detected in the Sun Valley neighborhood in northern Los Angeles County.  Two adult males, nine females, and 55 larvae have been detected. The U.S. Department of Agriculture (USDA), the Los Angeles County Agricultural Commissioner, and the California Department of Food and Agriculture (CDFA) are working collaboratively on the eradication.

The 89-square mile quarantine is in the northern San Fernando Valley of Los Angeles County, northwest of the City of Burbank.  It is bordered on the north by the Angeles National Forest; on the south by Griffith Park; on the west by I-405; and on the east by the Verdugo Mountains.  Additional information, and a link to the quarantine map, may be found here: www.cdfa.ca.gov/plant/medfly/regulation.html.

Increased numbers of sterile male Medflies are being released in the area as part of the eradication effort.  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 eliminate any mated females and reduce the density of the population. The flies lay their eggs in fruit, so crews will also remove fruit from trees within 100 meters of sites where larvae and multiple adult flies have been found.

Agricultural officials are working with fruit growers, wholesalers, and retailers in the area to ensure that the infestation does not spread through commercial channels. Local residents and home gardeners in the quarantine zone are urged to consume homegrown produce on site and not move it from their property.  These actions protect against the artificial spread of the infestation to nearby regions where it could affect California’s food supply and backyard gardens.

The sterile fly release program has a proven track record of eradication in California.  Sterile male flies mate with fertile female flies in the natural environment but produce no offspring.  The fly population decreases as the wild flies reach the end of their natural life span with no offspring to replace them.

The Medfly targets more than 250 types of fruits and vegetables, which could significantly impact California’s agricultural exports and backyard gardens. Damage occurs when the female lays eggs inside the fruit.  The eggs hatch into maggots and tunnel through the flesh of the fruit, making it unfit for consumption.

Residents who believe their fruits and vegetables are infested with fruit fly larvae should call the state’s toll-free Pest Hotline at 1-800-491-1899.

While fruit flies and other invasive species that threaten California’s crops and natural environment are sometimes detected in agricultural areas, the vast majority are found in urban and suburban communities.  These invasive species often enter our state by “hitchhiking” in fruits and vegetables brought back illegally by travelers returning from infested regions of the world.  To help protect California’s agriculture and natural resources, CDFA urges travelers to follow the Don’t Pack a Pest program guidelines (www.dontpackapest.com).