Citrus Pest and Disease Prevention Program

Oranges on TreeRecently, the California Department of Food and Agriculture (CDFA) and the United States Department of Agriculture discovered Huanglongbing, also known as HLB or citrus greening disease, in La Habra and Anaheim. HLB kills citrus trees and has no cure. The disease is not harmful to humans or animals. The disease is spread by a pest called the Asian Citrus Psyllid (ACP). ACP is a small insect that feeds on citrus tree leaves, which causes a bacteria called Huanglongbing to spread. If a tree is infected, it can die in as little as five years.

Strategies to Prevent the Spread of ACP

CDFA has implemented multiple strategies to deal with the pest including mandatory eradication, treatments, containment, and release of predatory wasps. A monitoring/detection system is in place for ACP using sticky traps located in host plants to help detect any possible infestations as well. Destruction of HLB-infected plants is the current method of eradication of HLB. There are various requirements in place for the movement of host fruit and host nursery stock. The restrictions that the quarantine imposes are that host plants, and portions thereof, cannot move out of the quarantine area. The quarantine prevents the sale of all host nursery stock and the movement of all host plants within a five-mile radius, and it applies to residents and commercial operations.

Emergency Response/Pest Management

HLB is a devastating disease of citrus and is spread through feeding action by populations of the Asian citrus psyllid (ACP), Diaphorina citri Kuwayama. In order to determine the extent of the infestation, and to define an appropriate response area, additional surveys took place for several days over a one-quarter-square-mile area, centered on the detection sites. Based on the results of the surveys, implementation of the CDFA’s ACP and HLB emergency response strategies is necessary for eradication and control.

The emergency program is based on recommendations developed in consultation with the California HLB Task Force, USDA experts on HLB and ACP, the Primary State Entomologist, the Primary State Plant Pathologist, and the affected counties agricultural commissioners’ representatives who are knowledgeable on HLB and ACP Incorporating these experts’ recommendations and findings, the program requires removal of all HLB-infected trees.

In determining how to respond to this emergency, the CDFA employs integrated pest management (IPM) principles. IPM includes cultural, biological, physical, and chemical control methods. The CDFA considered all relevant factors, data, and science and determined that cultural, biological, and chemical control methods would not abate the imminent threat posed by HLB-positive trees or meet its statutory obligations. Therefore, a physical method was selected, which includes the removal of any infected host plant. This option was selected based on minimal impacts on the environment, biological effectiveness, minimal public intrusiveness, and cost.

Residents of affected properties, which are unknown at this time, 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 concerns.

Residents shall be 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. 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. Treatment information is posted at http://cdfa.ca.gov/plant/acp/treatment_maps.html.

Home Prevention

To help prevent the spread of HLB, the California Department of Food and Agriculture recommends the following actions:

  • Keep homegrown citrus at home.
  • Regularly inspect your citrus trees and look for any signs of HLB or ACP (please see informational links listed above for ACP host list, pest information, descriptions, and distribution).
  • Do not move citrus plants, leaves, or foliage in or out of your community.
  • Talk to your local nursery about products that can protect your tree.

The CDFA’s ACP Project handles the regulatory aspects of these requirements (contact information listed below). If you believe you may have ACP, HLB, or any other pest, please contact the CDFA Pest Hotline at (800) 491-1899. Your information will be documented and tracked by CDFA and they will be able to help determine the pest you have and whether or not someone will need to collect an official sample. This process helps to streamline and prioritize efforts statewide.

Outreach and Public Education Campaign

The Citrus Pest & Disease Prevention Program has produced a series of short videos that provide an introduction to the issue, a description of what local agriculture officials are doing in the area, a description of the backyard treatment process, and a description of the tree removal program if HLB is found. Please visit the following website Citrus Pest and Disease Prevention Program to view videos and information to help raise awareness about the Asian citrus psyllid and the deadly citrus disease Huanglongbing.

Additional Information

For more information, please visit the Citrus Pest & Disease Prevention Program here. 

Quarantine Map

The HLB quarantine map for Orange County is available online: here