California Department of Food and Agriculture - Proclamation of Emergency Program for Asian Citrus Psyllild and Huanglongbing

"Between October 26, 2022 and November 21, 2022, the California Department of Food and Agriculture (CDFA) confirmed the presence of the causative bacterial agent of the citrus disease huanglongbing (HLB) in citrus tree tissue and the insect vector Asian citrus psyllid (ACP), Diaphorina citri Kuwayama. Citrus tree tissues and insect vectors were collected in the cities and communities of Bellflower, Downey, El Monte, La Puente, Long Beach, Montebello, Monterey Park, Norwalk, Pico Rivera, Rosemead, South El Monte, and Whittier in Los Angeles County. HLB is a devastating disease of citrus and is spread through feeding action by populations of ACP. HLB/ACP present a significant, clear, and imminent threat to California’s commercial citrus production, residential citrus plantings, natural resources, and economy. Unless emergency action is taken to disrupt the ACP life cycles, there is high potential for sudden future detections in Los Angeles County.

To determine the extent of the infestation, and to define an appropriate response area, delimitation surveillance took place for several days within a 250-meter radius area, centered on the detection site(s). Based on the results of the surveys, implementation of the CDFA’s ACP and HLB response strategies are necessary for eradication and control. In accordance with integrated pest management principles, CDFA evaluated possible treatment methods and determined that there are no cultural or biological control methods available to control the immediate spread of HLB/ACP in this area. The Proclamation of Emergency Program is valid until November 21, 2023, which is the amount of time necessary to determine that the treatment was successful. The detections of HLB/ACP described above require immediate action to address the imminent threat to California’s commercial citrus production, residential citrus plantings, natural resources, and economy. More specifically, in addition to a variety of commercial citrus crops, HLB/ACP threatens loss and damage to native wildlife, private and public property, and food supplies. Due to ACP being a vector for the bacteria that causes HLB and the rapid reproductive rate of ACP, there is a high potential for ACP to establish and spread, resulting in sudden future detections of HLB/ACP in the cities and communities listed above. Therefore, the Secretary of the California Department of Food and Agriculture is invoking Public Resources Code Section 21080(b)(4) to carry out immediate emergency action to prevent the aforementioned loss and damage to California’s resources.

The surveillance and treatment plan for the HLB/ACP infestation will be implemented within a 250-meter radius of each detection site, as follows:

  • ACP and HLB Survey. All host plants will be inspected for ACP and for HLB symptoms within a 250-meter radius around each ACP/HLB detection site, at least twice a year. ACP and host plant tissue will be collected and forwarded to a USDA accredited laboratory for identification and analysis.
  • ACP Treatment. All properties with host plants within a 250-meter radius around each HLB detection site shall be treated according to the following protocol to control ACP:
    • Tempo® SC Ultra (cyfluthrin), a contact insecticide for controlling the adults and nymphs of ACP, will be applied from the ground using hydraulic spray equipment to the foliage of host plants; and
    • Merit® 2F or CoreTect™ (imidacloprid), a systemic insecticide for controlling the immature life stages of ACP, will be applied to the soil underneath host plants. Merit® 2F is applied from the ground using hydraulic spray equipment. CoreTect™, which is used in place of Merit® 2F in situations where there are environmental concerns about soil surface runoff of liquid Merit® 2F, is applied by inserting tablets into the ground and watering the soil beneath the host plants.
  • Physical Control. All host plants found to be positive for HLB (infected with Candidatus Liberibacter asiaticus) will be removed and destroyed using mechanical means to stop the spread of the disease.
Public Notification:
Residents of affected properties shall be invited to a public meeting or contacted directly by CDFA staff. Consultation with the California Department of Pesticide Regulation, the Office of Environmental Health Hazard Assessment, and the county agricultural commissioner’s office will be provided at the public meeting or upon request to address residents’ questions and

Residents are notified in writing at least 48 hours in advance of any treatment in accordance with the Food and Agricultural Code sections 5771-5779 and 5421-5436. Following the treatment, completion notices are left with the residents detailing precautions to take and post-harvest intervals applicable to the citrus fruit on the property. Treatment information is posted at

Press releases, if issued, are prepared by the CDFA information officer and the county agricultural commissioner, in close coordination with the program leader responsible for treatment. Either the county agricultural commissioner or the public information officer serves as the primary contact to the media.

For any questions related to this program, please contact the CDFA toll-free telephone number at 800-491-1899 for assistance. This telephone number is also listed on all treatment notices."