California Department of Food and Agriculture (CDFA) and U.S. Department of Agriculture (USDA) officials have confirmed the detection of HLB in one tree in a residential property in the city of Calexico, Imperial County, California. This is the first HLB detection in a tree in Imperial County.
In November 2025, an Asian citrus psyllid (ACP) was confirmed positive in Imperial County for the bacteria that causes HLB. This was the first HLB-positive ACP finding in the county. ACP is the insect that spreads HLB from tree to tree.
The HLB detection triggers a mandatory 5-mile-radius quarantine area around the find site to restrict the movement of citrus fruit, trees and related plant material. The quarantine area is bordered on the north by McCabe Road, on the south by the U.S.-Mexico border, on the west by Rockwood Road and on the east by Barbara Worth Road. HLB quarantine maps are available on the CDFA Citrus Division website.
CDFA staff have treated and removed the infected tree in Calexico and are in the process of surveying all citrus trees within a 250-meter radius around the detection site. A treatment program for citrus trees to reduce ACP infestations will also be conducted 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 surrounding citrus from the disease.
The HLB quarantine prohibits the movement of all citrus nursery stock, host plants or plant parts out of the quarantine area. Provisions exist to allow the movement of commercially cleaned and packed citrus fruit. Fruit that is not commercially cleaned and packed must be kept on the property on which it is grown, although it may be processed and/or consumed on the premises.
HLB quarantine areas also exist in parts of Los Angeles, Orange, Riverside, San Bernardino, San Diego and Ventura counties. In those areas, more than 10,700 trees have tested positive for the disease and have been removed since 2012.
CDFA, in partnership with the USDA, local county agricultural commissioners and the citrus industry, continues to pursue a strategy of controlling the spread of the ACP.
Learn more about protecting California citrus from HLB and ACP here.
Source: CDFA
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