A newly established quarantine area has been declared following the detection of the deadly citrus plant disease Huanglongbing (HLB) in five trees located on a residential property with non-commercial citrus acreage in the Valley Center area of San Diego County. This is the first time the disease has been confirmed in Valley Center, marking the third area in San Diego County to have had a positive detection of HLB. The California Department of Food and Agriculture (CDFA) is working with the United States Department of Agriculture (USDA) and San Diego County to ensure the HLB-infected trees are removed in a timely manner in order to prevent the spread of HLB into neighboring areas.

This detection results in the establishment of an HLB quarantine area with a five-mile radius around the find site. The quarantine prohibits residents and commercial operations from moving any host plants within or out of the area, and fruit grown in the area must undergo additional mitigation steps before it can be transported within or from this area. The quarantine zone will not intersect with the existing quarantine boundaries in the Oceanside and Rancho Bernardo areas of San Diego County.

The updated HLB quarantine maps for San Diego County are now available online. Please check this link for future quarantine expansions, should they occur.

CDFA staff is in communication with the property owner to ensure the infected trees are removed and are in the midst of implementing a treatment program for all citrus trees within 250-meters of the find site. By taking this action, a critical reservoir of the disease and its vectors will be removed, which is essential to protect other citrus trees on the property, neighboring citrus trees and the community's citrus from this deadly disease. CDFA, in partnership with USDA, local County Agricultural Commissioners and the citrus industry, continue to pursue a strategy of controlling the spread of the Asian citrus psyllid while researchers work to find a cure for HLB.

Questions? If you are a citrus grower in San Diego County and have questions about this detection, please contact your Grower Liaison Sandra Zwaal at szwaal2@gmail.com.

HLB Update - Ventura County Detections

As of November 17, a total of 57 trees and 5 ACP samples in Ventura County have been confirmed positive for CLas, the bacterium that causes HLB. All detections are in a residential area of Santa Paula. CDFA crews are working to complete treatment and removal of the infected trees. CDFA is also conducting mandatory surveys and ACP treatments of all citrus within 250m of the tree detections. Currently there is no commercial citrus in the 250m delimitation areas.

In addition to Ventura, counties where HLB has been detected via PCR testing are Los Angeles, Orange, San Diego, Riverside, San Bernardino and San Diego, with the majority of detections in Orange County. To see a map of the current HLB quarantine areas, and other details of HLB detections, please visit maps.cdfa.ca.gov/WeeklyACPMaps/HLBWeb/HLB_Treatments.pdf. This site is usually updated weekly on Fridays.