Mediterranean fruit fly

Medfly Quarantine Issued in Los Angeles County

Brian GermanIndustry, Pest Update

The northern Los Angeles County neighborhood of Sun Valley has been placed under quarantine after a Mediterranean fruit fly (Medfly) infestation was detected.  The 89-square mile quarantine was issued after the detection of two adult males, nine females, and 55 larvae.

MedflyThe U.S. Department of Agriculture (USDA), along with the Los Angeles County Agricultural Commissioner, and the California Department of Food and Agriculture (CDFA) are working together on eradication methods.  Officials are working with fruit growers, wholesalers, and retailers in the surrounding area to prevent the spread of further infestation through commercial channels.

Sterile male Medflies are being released in the areas of detection.  The program has shown a good success rate in eradicating the pest in previous instances. As the flies naturally die off there will be no offspring to replace them, effectively reducing the overall population.

Properties that are within 200 meters of detection sites will be treated with an organic formulation of Spinosad to eliminate mated females and reduce the density of the population.  Crews will also be working to remove fruit from trees within 100 meters of areas where larvae and mature flies have been detected.

The Medfly can infect over 250 different types of fruits and vegetables.  The pest poses great potential for causing significant damage to crops and adversely affecting California’s agricultural exports and backyard gardens. Female flies lay eggs inside the fruit, which eventually hatch into maggots that tunnel through the fruit, making it unfit for consumption.

The majority of fruit flies and other invasive species are found in urban and suburban communities.  These invasive species most often enter California through travelers illegally bringing back infested fruits and vegetables from regions of the world with high infestation rates.  Proactive measures are necessary to protect against the spread of infestation to agricultural regions where it could significantly impact production.

Methods to report fruits and vegetables infested with fruit fly larvae and information on the quarantine map can be found on the CDFA website.