On July 5, 2024, the USDA’s Animal and Plant Health Inspection Service (APHIS) and the California Department of Food and Agriculture (CDFA) released portions of Riverside County, California, from the Riverside/San Bernardino Counties Oriental fruit fly (Bactrocera dorsalis; OFF) quarantine.

The areas released include the cities of Jurupa Valley, Moreno Valley, and Riverside. On July 6, APHIS and CDFA removed the OFF quarantine in Brentwood, Contra Costa County, California. Release from quarantine occurred after three generations elapsed with no additional detections in these areas.

The reduction of the Riverside/San Bernardino Counties quarantine releases 189 square miles including 4,700 acres of commercial agriculture from quarantine. Approximately 365 square miles remain under quarantine, primarily in San Bernardino County, including 1,800 acres of commercial agriculture.

On September 27, 2023, APHIS and CDFA established the OFF quarantine in the city of Redlands in San Bernardino County following detections of OFF, as described in DA-2023-17, and expanded the quarantine on October 3 and 12, November 3, 9, 17 and 28, and December 5 and 22, following detections of additional flies in various locations in Riverside and San Bernardino Counties. The quarantine release date was based on a degree-day model from the last detection in these portions of Riverside County on November 28, 2023.

The removal of the Contra Costa County quarantine releases 99 square miles including 939 acres of commercial agriculture from quarantine. APHIS and CDFA established the quarantine on September 6, 2023, following the confirmed detections of six adult male OFF from various sites in Brentwood between August 25 and August 30, 2023.

Between August 30 and October 20, CDFA confirmed eight additional male and two unmated female OFF from Brentwood. The quarantine release date was based on a degree-day model from the date of the last detection.

APHIS restricted the interstate movement of regulated articles from these areas to prevent the spread of OFF to non-infested areas of the United States. APHIS has worked cooperatively with CDFA and the Contra Costa County and Riverside County Agricultural Commissioners to eradicate these transient OFF populations through various control actions per program protocols.

The removal and reduction of these quarantine areas is reflected on the APHIS Exotic Fruit Flies website, which contains a description of all current federal fruit fly quarantine areas. APHIS will publish a notice of these changes in the Federal Register.