The USDA's Animal and Plant Health Inspection Service (APHIS), in collaboration with the California Department of Food and Agriculture (CDFA), has announced a new quarantine zone in California to address sweet orange scab (SOS), caused by the fungus Elsinöe australis. The quarantine area covers approximately 91 square miles in the Burbank region of Los Angeles County.

Sweet orange scab is characterized by pustules that create a corky appearance on the fruit. While the infection can affect young nursery trees and new plantings, potentially causing premature fruit drop and blemishes that reduce marketability, it does not compromise fruit quality or pose health risks to humans. The fungus is spread primarily through rain, irrigation, and movement of infected plants, and its damage is superficial.

Since its initial identification in the United States in 2010 on residential citrus trees in Texas, sweet orange scab has been confirmed in several states, including Alabama, Arizona, California, Florida, Louisiana, and Mississippi.

The recent quarantine in Los Angeles County was initiated following the detection of SOS in a plant tissue sample from a residential property. This expansion of quarantine focus does not include commercial citrus operations. APHIS is implementing measures to regulate the interstate movement of regulated articles from the quarantined area, aligning with previous intrastate restrictions established by CDFA on May 29, 2025. These efforts aim to prevent the further spread of sweet orange scab within the United States.