APHIS Expands the Mexican Fruit Fly (Anastrepha ludens) Quarantine Area in California

FOR INFORMATION AND ACTION 
DA-2026-16 
April 17, 2026
 

Subject: APHIS Expands the Mexican Fruit Fly (Anastrepha ludens) Quarantine Area in California 

To: State, Tribal, and Territory Agricultural Regulatory Officials

On March 17 and April 2, 2026, the Animal and Plant Health Inspection Service (APHIS) and the California Department of Food and Agriculture (CDFA) expanded the La Mesa Mexican fruit fly (Anastrepha ludens; Mexfly) quarantine in San Diego County, California.

On March 17, APHIS and CDFA expanded the La Mesa Mexfly quarantine following the confirmed detections on March 11 of one wild mated female Mexfly and one wild male Mexfly from a trap in an orange tree and one wild male Mexfly from a trap in an avocado tree. This action expanded the quarantine by one square mile and does not include commercial agriculture. On April 2, APHIS and CDFA further expanded the La Mesa Mexfly quarantine in response to the confirmed detection on March 25 of one wild unmated female Mexfly from a trap in an orange tree. This action expanded the quarantine by one square mile and does not include commercial agriculture. The amended quarantine encompasses 84 square miles and contains no commercial agriculture. All detections were on residential properties.

APHIS is applying safeguarding measures and restrictions on the interstate movement of regulated articles to prevent the spread of Mexfly to non-infested areas of the United States, as well as to prevent the entry of these fruit flies into foreign trade. APHIS is working with CDFA and the Agricultural Commissioner of San Diego County to eradicate this transient fruit fly population following program guidelines for survey, treatment, and regulatory actions.

The APHIS Exotic Fruit Flies website contains descriptions and maps of all current Federal fruit fly quarantine areas. APHIS will publish a notice of this change in the Federal Register.

For additional information you may contact: 

Catherine Marzolf 
National Policy Manager 
386-666-9932 
catherine.a.marzolf@usda.gov

Glorimar Marrero 
Assistant National Policy Manager 
240-577-4633 
glorimar.marrero@usda.gov

/s/

Matthew A. Rhoads 
Deputy Administrator 
Plant Protection and Quarantine