New Oriental Fruit Fly Quarantines for Parts of Southern California

Portions of San Bernardino and Riverside counties in Southern California have been placed under quarantine for the Oriental fruit fly following the detection of multiple flies in the two counties.

Detections in and around the cities of Ontario and Jurupa Valley have resulted in a quarantine zone covering 131 square miles (57 sq. miles in Riverside County and 74 in San Bernardino County), bordered on the north by Highway 210; on the south by Norco; on the west by Ontario; and on the east by Rubidoux. A link to the quarantine map can be viewed here.

The Oriental fruit fly is known to target over 230 different fruits, vegetables, and plant commodities. Important California crops at risk include pome and stone fruits, citrus, dates, avocados, and many vegetables, particularly tomatoes and peppers. Damage occurs when the female fruit fly lays her eggs inside the fruit. The eggs hatch into maggots, which tunnel through the flesh of the fruit, making it unfit for consumption.

This invasive pest is widespread throughout much of the mainland of southern Asia and neighboring islands, including Sri Lanka and Taiwan, and it has invaded other areas, most notably Africa and Hawaii.

Following the principles of Integrated Pest Management, agricultural officials use the “male attractant” technique as the mainstay of the eradication effort for this invasive species. This approach has successfully eliminated dozens of fruit fly infestations in California. Trained workers apply a small amount of fruit fly attractant mixed with a very small dose of an organic pesticide, Spinosad, approximately 8 to 10 feet off the ground on street trees and similar surfaces. Male fruit flies are attracted to the mixture and perish after consuming it. The male attractant technique is being carried out over an area that extends 1.5 miles from each site where oriental fruit flies have been trapped.

For more information, visit cdfa.ca.gov.