Seven invasive fruit fly quarantines are in place throughout California. If you live within one of these quarantine zones, fruits and vegetables should not be moved off the property they were grown on. Quarantines are in place for the Mediterranean fruit fly, Oriental fruit fly, tau fruit fly, and Queensland fruit fly. Smuggled, illegally imported fruit is the most common pathway of fruit fly entry into California.
These fruit flies lay their eggs under the skin of many crops, making their detection difficult. Females of some species can lay 1,000 eggs in their lifetime. Once eggs hatch, larvae (maggots) feed on the inside of the fruit. Infested fruit drops to the ground where larvae leave the fruit to burrow into the soil to pupate. Numerous generations can occur each year.
Invasive fruit flies pose a major threat to California agriculture as they make fruit unfit for human consumption and damage a wide variety of crops from fruits to vegetables. In addition, they pose an economic burden to commercial growers in quarantine zones as they must treat all host fruit with an approved pesticide before sale or movement within or outside of the quarantine area. You can help prevent the spread of these invasive pests and reduce the risks they pose to commercial fruit and vegetable producers by not moving homegrown produce and cleaning up and disposing of dropped fruit.
Quarantine zones include:
Mediterranean fruit fly
- Los Angeles County, Leimert Park Area
Oriental fruit fly
- San Bernardino and Riverside Counties, Redlands, Yucaipa, Highland, San Bernardino, and Riverside Areas
- Sacramento County, Rancho Cordova Area
- Contra Costa County, Brentwood Area
- Santa Clara County, Santa Clara Area
Tau fly
- Los Angeles County, Stevenson Ranch, Valencia, Santa Clarita Areas
Queensland fruit fly
- Ventura and Los Angeles Counties, Thousand Oaks Area
Quarantine zones updated December 5, 2023. To view the most up-to-date quarantine maps, visit the CDFA webpage at https://www.cdfa.ca.gov/plant/pe/InteriorExclusion/quarantine.html.
If you live in a fruit fly quarantine zone:
- Do not take fresh fruits and vegetables off your property. Don't share with neighbors or ship to friends and family in other counties or states.
- Consume or process (i.e., juice, freeze, or cook) all fruits and vegetables where they are grown.
- Dispose of homegrown fruits and vegetables by double-bagging and sealing then placing them in the trash–not in your green waste or compost bin.
Suspect you have an invasive fruit fly infestation? Contact the California Department of Food and Agriculture (CDFA) Pest Hotline: 1-800-491-1899 or your County Agricultural Commissioner. Allow authorized CDFA workers access to your property to inspect fruit, set traps, or conduct fruit fly eradication activities. Your cooperation helps protect California agriculture!
While the holiday season is a time of giving, we urge you to not share these invasive fruit flies!
[Revised from this California Dept. of Food and Agriculture (CDFA) blog post.]