Effective Aug. 19, USDA’s Animal and Plant Health Inspection Service (APHIS), in cooperation with the California Department of Food and Agriculture (CDFA), expanded the area quarantined for sweet orange scab (SOS) in the Burbank, Los Angeles and Long Beach areas of Los Angeles County and the Anaheim and Garden Grove areas of Orange County. SOS is a disease caused by the fungus Elsinöe australis. APHIS is expanding the quarantined area by 110 square miles in Los Angeles County and 67 square miles in Orange County. APHIS is taking this action because of SOS detections in plant tissue samples collected from residential properties in Los Angeles and Orange Counties. There are 2.5 acres of commercial citrus impacted by the Anaheim and Garden Grove area expansion
APHIS is applying safeguarding measures outlined in Federal Order DA-2024-34 pertaining to the interstate movement of regulated articles from the quarantined areas in California. This measure parallels the intrastate quarantine that CDFA established on June 18, 2026. This action is necessary to prevent the spread of SOS to non-infested areas of the United States
The APHIS Sweet Orange Scab webpage has information on this disease, Federal Orders, APHIS approved packinghouse procedures, and a description of current Federal SOS quarantined areas.
The California Department of Food and Agriculture (CDFA) announced it is expanding its sweet orange scab (SOS) quarantine in the La Puente area of Los Angeles County (grids 456 and 457). The quarantine is effective as of April 8.
SOS is believed to be caused by Elsinöe australis, a fungal pathogen. The disease results in the formation of pustules and lesions on the skin of the citrus.
Regulated articles and conditions for intrastate movement under the quarantine can be found at Title 3 of the California Code of Regulations section 3443. Interested parties and local entities may request to lift the quarantine area designations by submitting a written appeal supported by convincing evidence. Appeals must be filed within 10 working days of the notification. Quarantines will remain in effect during the appeal’s pending. Appeals can be mailed to: CDFA – Citrus Division 1220 N. St. Sacramento, CA 95814.
The California Department of Food and Agriculture (CDFA) and the United States Department of Agriculture (USDA) have confirmed the detection of the citrus disease known as Huanglongbing (HLB), or citrus greening, in Riverside County. The disease was detected in plant material taken from a grapefruit tree in a residential neighborhood in the city of Riverside near I-215.
The infected tree has been removed and agriculture officials are moving swiftly on mandatory surveying in an 800-meter area. Mandatory treatments will soon follow. CDFA staff will visit all regulated entities in the quarantine area, including retail and production nurseries and packinghouses. Additionally, local, state and federal agriculture authorities are working together to determine potential implications to the University of California, Riverside, which will fall within the 5-mile quarantine area.
Riverside County Agricultural Commissioner/Sealer Ruben Arroyo plans to take an aggressive stance on any abandoned groves in the area, and the Citrus Pest & Disease Prevention Program outreach team is already working with the City of Riverside to inform residents of the actions needed to stop HLB’s spread.
Sacramento, Calif., (May 25, 2017) – The California Department of Food and Agriculture (CDFA) and the United States Department of Agriculture (USDA) have confirmed the detections of the citrus disease known as huanglongbing (HLB), or citrus greening in Orange County. The disease was detected in plant material taken from a lemon tree in a residential neighborhood in La Habra and from three trees (2 lemon, 1 grapefruit) in a residential neighborhood in Anaheim. HLB is a deadly disease of citrus plants and closely related species, and can be transmitted from tree to tree by the Asian citrus psyllid.
CDFA,in cooperation with the USDA and the Orange County Agricultural Commissioner, has begun an extensive survey and limited treatment program in response to the detections. CDFA crews have removed and disposed of the infected trees and are preparing to conduct treatment of citrus trees for Asian citrus psyllid infestations within 800 meters of the find sites. By taking these steps, a critical reservoir of the disease and its vectors will be removed, which is essential to protect the surrounding citrus from this deadly disease.
HLB is a bacterial disease that attacks the vascular system of plants. It does not pose a threat to humans or animals. The Asian citrus psyllid can spread the bacteria as the pest feeds on citrus trees and other plants. Once a tree is infected, there is no cure; it typically declines and dies within a few years.
CDFA has expanded an existing HLB quarantine to include a portion of La Habra and will soon expand it further to Anaheim. The quarantine prevents the sale of all host nursery stock and the movement of all host plants and fruits within a five-mile radius of the find sites, and applies to residents and commercial operations alike. The HLB quarantine maps for Los Angeles and Orange Counties are available online at: www.cdfa.ca.gov/plant/pe/InteriorExclusion/hlb_quarantine.html. Please check this link for future quarantine expansions in these counties, should they occur. Quarantines in new counties will be announced separately.
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 Asian citrus psyllids while researchers work to find a cure for the disease.
HLB is known to be present in Mexico and in parts of the southern United States. Florida first detected the pest in 1998 and the disease in 2005, and the two have now been detected in all 30 citrus producing counties in that state. The University of Florida estimates that the disease causes an average loss of 7,513 jobs per year, and has cost growers $2.994 billion in lost revenue since HLB was first detected there.
The Asian citrus psyllid was first detected in California in 2008, and quarantines for the pest are now in place in 29 California counties. If Californians have questions about the ACP or HLB, they may call CDFA’s toll-free pest hotline at 1-800-491-1899 or visit: www.cdfa.ca.gov/plant/acp/
Credit: UC Riverside – UC Riverside researchers (from left) Philippe Rolshausen, David Jassby, Haizhou Liu, Caroline Roper, Georgios Vidalakis and James Borneman received a $5.1 million grant to fight a disease killing citrus trees.
Riverside, Calif., (February 24, 2017) – A team of scientists, led by a group at the University of California, Riverside, has received a five-year, $5.1 million grant from the U.S. Department of Agriculture to fight a disease that is devastating the citrus industry.
The team, led by Caroline Roper, an associate professor of plant pathology, will design and identify bactericides, which are chemicals that kill bacteria, to target Huanglongbing, a bacterial plant disease decimating citrus trees worldwide. They also will focus on better understanding the pathways those bactericides travel inside citrus trees.
Huanglongbing, which has devastated citrus trees in Asia and South America, was detected in Florida in 2005 and has since led to a 75 percent decline in the Florida’s $9 billion citrus industry. Fifteen U.S. States or territories are under full or partial quarantine due to the presence of the Asian citrus psyllid, an insect which feeds on citrus trees and – in doing so – transmits Huanglongbing.
Past research has identified the bacterium (Candidatus Liberibacter asiaticus or CLas) associated with Huanglongbing that is killing citrus trees. But, it has proved difficult to deliver bactericides to the phloem, the part of the citrus tree where the harmful bacteria resides.
The UC Riverside team will analyze phloem transit routes that bactericides take when introduced through common application methods, such as trunk injection or leaf or root applications.
They also will continue to develop a new delivery system for use in field citrus trees. The delivery system targets the branches and petioles, which are the stalk that join a leaf to a stem. The idea is based on previous work that indicates that this is an effective and efficient way to tap into and introduce material into phloem tissue, a tissue that is hard to access.
They also will conduct fluorescent tracer experiments that map phloem transport pathways in citrus and harness that information to predict and test the routes that bactericides take when introduced. This will yield information about the routes bactericides travel when administered through delivery methods used by growers and the branch/petiole feeding technique.
The researchers will develop two classes of bactericides, the first based on mining anti-CLas compounds naturally produced by microbes that inhabit Huanglongbing survivor trees in Florida, and the second based on silver and sulfur nanoparticles.
Finally, the researchers will also undertake an extension and outreach program for citrus growers and non-commercial citrus growers (homeowners and hobbyists). They also will perform an economic cost-benefit analysis for adoption of these treatments in the commercial citrus industry.
In addition to Roper, the following UC Riverside scientists are involved: James Borneman, Philippe Rolshausen, David Jassby, Georgios Vidalakis, and Haizhou Liu. And, the following researchers from other institutions are involved: Robert Turgeon (Cornell University); Katherine Maloney (Point Loma Nazarene University); Pieter Dorrestein (UC San Diego); Greg McCollum (U.S. Department of Agriculture), and Jonathan Kaplan (California State University, Sacramento).
The grant is one of four given by the U.S. Department of Agriculture’s National Institute of Food and Agriculture (NIFA) to combat Huanglongbing. The funding is made possible through NIFA’s Specialty Crop Research Initiative Citrus Disease Research and Extension Program, authorized by the 2014 Farm Bill.
