Citrus Quarantine Program (CQP)

Asian Citrus Psyllid

The department’s Citrus Quarantine Program (CQP) supports and promotes the local citrus industry by enforcing Asian Citrus Psyllid (ACP) and Huanglongbing (HLB) quarantine regulations. Inspections conducted by CQP inspectors ensure compliance in order to suppress the movement of ACP and therefore mitigate the potential spread of HLB.


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IMPORTANT INFORMATION: Press Release: First Citrus Quarantine Established In San Diego County

The California Department of Food and Agriculture declared a quarantine in parts of north San Diego County Thursday, August 5, 2021, after detecting a potentially devastating citrus disease in the county for the first time.

The bacterial disease, known as Huanglongbing or “citrus greening,” was detected in two citrus trees on a residential property in Oceanside. The disease is not harmful to people but is deadly to citrus and could be devastating to the county’s citrus industry. Huanglongbing  is spread by tiny insects, the Asian citrus psyllid, if they are carrying the bacterium when they feed on citrus plants and trees.

California Department of Food and Agriculture (CDFA) officials said the 60-square-mile quarantine area will prohibit people and businesses from moving citrus nursery stock, plant parts and fruit outside the quarantine boundaries, with the exception of commercially cleaned and packed fruit that adhere to specific requirements. The quarantine also prohibits people from moving residential citrus plants and plant parts off the properties on which they are grown.

The quarantine area is bordered on the north by Vandergrift Boulevard; on the south by Carlsbad Village Drive; on the west by the Pacific Ocean; and on the east by Melrose Drive.

“Unfortunately, Huanglongbing is fatal to citrus,” said San Diego Agricultural Commissioner Ha Dang, “so our goal is to stop this from spreading any farther. By working together, we can all protect San Diego County’s $150 million citrus industry from this deadly disease.”

The California Department of Food and Agriculture  (CDFA), the United States Department of Agriculture and San Diego County’s Department of Agriculture, Weights and Measures (AWM) are working together on the quarantine. Work includes treating the residential location where the disease was found, establishing the quarantine boundaries and notifying businesses and residents within the quarantine area.

CDFA and AWM will coordinate informational meetings for commercial growers, nurseries and residents in the quarantine area. AWM will have information available on its website with links to Google translator that can translate the information into multiple languages.

Dang said this was a critical time for homeowners to protect their backyard citrus trees by searching for evidence of the Asian citrus psyllid and the disease.

Huanglongbing affects the vascular system of citrus trees and plants. Once a tree is infected, it cannot be saved and will die within a few years.

Huanglongbing symptoms include blotchy yellowing of leaves, yellow shoots, lopsided, small and rancid-tasting fruit, and premature, excessive fruit drop. If people are not sure if their plants are infected, they can contact the CDFA “Report-a-Pest” hotline at 1-800-491-1899.

Inside the quarantine area, CDFA urged residents to take the following steps:

  • Do not move citrus plants, leaves or foliage into or out of the quarantine area.
  • Cooperate with agricultural officials who are placing traps, inspecting trees and treating for the pest.
  • If you no longer wish to care for your citrus tree, consider removing it so it does not become a host to the pest and disease.

Inspectors first found the Asian citrus psyllid in San Diego County in 2008. But this is the first time they have found Huanglongbing disease. There are existing Huanglongbing quarantine areas in parts of Orange, Los Angeles, Riverside and San Bernardino counties, where more than 2,400 trees have tested positive for the disease and been removed.

Commercial growers in the quarantine area can contact Sandra Zwaal at for more information. Zwaal is the Asian Citrus Psyillid Huanglongbing Grower liaison for the California Citrus Pest & Disease Prevention Program, which is primarily funded by California growers and CDFA. Zwaal will also be working with the San Diego County Farm Bureau and San Diego County Pest Control District.

Nurseries and retail businesses that sell citrus should contact CDFA Environmental Scientist Jemellee Urbino at for more information.

Maps of the quarantine area and updated information can be found on CDFA’s website Please check this link for future quarantine expansions, should they occur.

HLB Quarantine





Click here and then enter your address to see

if you reside in the quarantine zone.

***IMPORTANT***- Below are key messages regarding Huanglongbing and the Asian Citrus Psyllid for Consumers and Homeowners:

Key Messages


  • There is no cure for the disease/Huanglongbing. Once a tree is infected, it’s like a death sentence and it will die.
  • Now is a critical time for homeowners to protect their backyard citrus trees by searching for the Asian citrus psyllid and Huanglongbing, also known as HLB or citrus greening disease. 
  • The Asian citrus psyllid is similar in size to an aphid. Adults are brown, about 1/8th of an inch long, and feed with their bodies at a 45-degree angle.
  • Young Asian citrus psyllids are yellowish orange and produce a white, waxy substance that can be seen on leaves.
  • Adults, juveniles and eggs are typically found on tender, new leaves.
  • Symptoms of HLB include blotchy, yellowing of leaves; yellow shoots; lopsided, small and rancid-tasting fruit; and premature and excessive fruit drop.
  • Report [ACP/HLB] symptoms immediately to CDFA at 1-800-491-1899.


  • There is no cure for HLB. When a tree is infected, it’s like a death sentence and it will die. 
  • Residents should inspect their trees for signs of HLB and report any suspicious symptoms immediately to CDFA. 
  • Residents should cooperate with agriculture officials – allow them to access your property to look for the disease.
  • HLB is not harmful to humans or animals, but it is fatal for citrus trees.
  • HLB has already been found in Southern California, and we need to work to keep it from killing more trees in the state. 
  • HLB infected trees need to be removed to protect other trees, the community’s citrus, and the state’s vibrant commercial citrus industry. 
  • If the pest and disease are not stopped, it will destroy citrus trees in residential neighborhoods. We should all help prevent the disease/Huanglongbing from spreading. 


Residents are critical to the fight and should: 

  • Not move citrus plants, leaves, or foliage into or out of quarantine areas or across state or international borders. Keep it local. 
  • Buy trees from reputable, licensed California nurseries. 
  • When grafting, use only registered budwood with source documentation. 
  • Dry or double bag citrus plant material prior to disposal.
  • Talk to your local home and garden center about products that can protect against the Asian citrus psyllid.
  • Consider removing unwanted or uncared for citrus trees so they do not become a host to the pest or disease.  



  • The HLB quarantine prohibits the movement of all citrus plant material into or out of the quarantine area.
  • Provisions exist to allow the movement of commercially cleaned and packed citrus fruit. 
  • Fruit must be thoroughly washed and free of leaves and stems before it is moved from the property on which it is grown.

Visit to learn more about the pest and disease 


Learn how to support the HLB fight as a citrus hobbyist at FruitMentor’s Youtube page (links below)


Dangers of Moving Citrus Fruit in California (Vietnamese)

English / Español / Tiếng Việt / 한국어 / 普通话 / 粵語


The Citrus Pest & Disease Prevention Program (CPDPP) Released a new 30-second Public Service Announcement (PSA), “What If California Citrus Disappeared?”

What if citrus disappeared?

California Citrus Pest and Disease Prevention Committee (CPDPC) endorses “Best Practices for Growers in Response to HLB in California.”

To provide California citrus growers with a strong toolbox of options to protect their orchards from Huanglongbing (HLB), the Citrus Pest & Disease Prevention Committee has endorsed the following “Best Practices for Growers in Response to HLB in California.” The recommendations – which are grouped based on a grower’s proximity to an HLB detection – represent the most effective tools known to the citrus industry at this time and are meant to supplement the California Department of Food and Agriculture’s required regulatory response.

Growers are encouraged to use as many methods as feasible for their operation in order to limit the spread of the Asian citrus psyllid (ACP) and HLB, as the cost to manage the Asian citrus psyllid is far less than any potential costs or loss to the industry should HLB take hold throughout our state.

Please visit for more information.


Huanglongbing (HLB) Sampling for Growers

HLB Sample Collection and Submission Protocol

Citrus Pest Detection Program (CPDP) Services

The following are links that are provided to assist both homeowners and industry members alike.


Citrus Pest & Disease Prevention Program (CPDPP)

Homeowner Oriented:

Industry Oriented:


California Department of Food and Agriculture (CDFA) ACP Information

CDFA Notice of Treatment (NOT) Information

CDFA currently coordinates areawide treatments for ACP present in San Diego county when no other mitigation methods are available. CDFA posts Notices of Treatment (NOTs) at least 48 hours in advance of any treatment. To view NOTs for San Diego county, please click here.


United States Department of Agriculture Animal and Plant Health Inspection Service (APHIS) Citrus Information


Contact Information

Residents can contact the San Diego County Dept. of Agriculture, Weights & Measures’

Citrus Quarantine Program at or by calling (858) 614-7770 for more information.

Commercial Growers can also contact the San Diego County Grower Liaison, Sandra Zwaal, at for more information.


Entomology Lab

Email (Please put “Entomology” in the subject line to ensure timely routing) or call (858) 614-7738 for more information.