First CLas-positive Asian citrus psyllid found in San Diego County

Southern California

An Asian citrus psyllid (ACP) sample – confirmed positive for Candidatus Liberibacter asiaticus (CLas), the bacteria that causes Huanglongbing (HLB) – was collected from a residential property in the Fallbrook area of San Diego County. Confirmed by Citrus Research Board’s Jerry Dimitman Laboratory, this adult psyllid sample is the first CLas-positive ACP found in San Diego County.

While the first confirmation of a CLas-positive ACP in San Diego County is concerning, as of today, HLB has not been detected in any San Diego County trees but surveying and sampling of area trees is ongoing. This find signals a critical time for homeowners and growers alike to continue to control ACP populations to stop the potential spread of this deadly disease, as oftentimes a CLas-positive ACP precedes the detection of an HLB-positive tree.

The HLB quarantine zone will not be expanded as a result of this CLas-positive ACP detection and CDFA staff is swiftly conducting surveys and collecting samples from HLB host plants that are located within a 250-meter radius around the find, per the ACP/HLB Action Plan.

While treatment is not mandatory for area commercial growers as a result of the detection, San Diego County commercial growers who have additional questions can contact Sandra Zwaal, San Diego County Grower Liaison, at szwaal2@gmail.com.

For additional details on the CLas-positive ACP detection, visit www.countynewscenter.com/state-and-county-investigate-citrus-disease-in-fallbrook/


Asian citrus psyllids found in Fresno County


The California Department of Food and Agriculture’s Plant Pest Diagnostic Center (PPDC) has...
Read More

San Joaquin Valley

Tulare County Citrus Grower Meeting and ACP Update: Friday, May 20


Citrus growers and industry members with operations in Tulare County are invited to attend a...
Read More

San Joaquin Valley

Industry Members Encouraged to Increase Vigilance Following Recent ACP Detections


Following recent Asian citrus psyllid (ACP) detections in the Central Valley over the last few...
Read More

San Joaquin Valley

San Diego County Citrus Grower Meetings – April 27 and 30


Citrus growers and industry members in San Diego County are invited to attend an in-person San...
Read More

Southern California