Official Pest Report

Official Pest Reports are provided by National Plant Protection Organizations within the NAPPO region. These Pest Reports are intended to comply with the International Plant Protection Convention's Standard on Pest Reporting, endorsed by the Interim Commission on Phytosanitary Measures in March 2002.

Bactrocera dorsalis (Oriental Fruit Fly): APHIS Establishes a Quarantine in Brentwood, Contra Costa County, California

Country: United States


Bactrocera dorsalis (Oriental Fruit Fly): APHIS Establishes a Quarantine in Brentwood, Contra Costa County, California

Richard Johnson, Fruit Fly National Policy Manager, at (301) 851-2109 or


On September 6, 2023, the Animal and Plant Health Inspection Service (APHIS) and the California Department of Food and Agriculture (CDFA) established an Oriental fruit fly (Bactrocera dorsalis or OFF) quarantine in Brentwood, Contra Costa County, California. This action is in response to the confirmed detections of six adult male OFF from various sites in Brentwood by CDFA between August 25 and August 30. Between August 30 and September 5, CDFA confirmed seven additional male OFF from Brentwood. All were from traps in various types of trees in residential areas. 

APHIS is applying safeguarding measures and restrictions on the interstate movement or entry into foreign trade of regulated articles from the area to prevent the spread of OFF to non-infested areas of the United States. In cooperation with CDFA, APHIS is establishing a quarantine area encompassing 99 square miles of Contra Costa County. There are 939 acres of commercial agricultural production of OFF host crops in the quarantine area, including apricots, nectarines, grape, squash, walnuts, and cherries. APHIS is working with CDFA and the Contra Costa County Department of Agriculture to respond to these detections following program survey, treatment protocols, and regulatory responses.

The establishment of this quarantine area is reflected on the following website, which contains a description of all current Federal fruit fly quarantine areas:

Under IPPC standards, Bactrocera dorsalis  is a transient pest under eradication that is present only in two areas in California. This species is not widely distributed and is under official control in the United States.

Posted Date: Sept. 29, 2023, 3:18 p.m.