A new quarantine has been put in place in Ramona, California, following the detection of Huanglongbing (HLB), also known as citrus greening disease, in residential citrus trees. The California Department of Food and Agriculture (CDFA) confirmed the presence of HLB after testing trees on a private property. This marks the first time Ramona has come under quarantine for this disease, joining other affected areas in San Diego County such as Fallbrook, Oceanside, Rancho Bernardo and Valley Center.
HLB is a serious threat to citrus crops worldwide. The disease is caused by a bacterium spread by the Asian citrus psyllid, an insect that feeds on citrus leaves. Symptoms include yellowing leaves, misshapen or bitter fruit and eventual tree death. There is currently no cure for HLB. While it does not pose a risk to human health, it can severely impact commercial citrus production.
California is one of the largest citrus-producing states in the U.S., with thousands of acres dedicated to oranges, lemons, mandarins and other varieties.
For more than ten years, scientists and specialists have worked to contain HLB’s spread in California. Experts from the University of California Division of Agriculture and Natural Resources (UC ANR) have conducted research and outreach programs focused on monitoring the Asian citrus psyllid, integrated pest management and community education to help prevent further transmission.
Through UC Cooperative Extension programs, agricultural advisors and scientists collaborate with growers, nurseries and homeowners to detect the insect early, implement control strategies and encourage practices that reduce risk between trees. Many cases identified across California have involved residential trees rather than commercial groves. This highlights the need for local residents’ involvement in prevention efforts.
When HLB is detected, quarantines restrict movement of citrus trees, branches, leaves and fresh fruit out of affected zones to stop further spread.
Authorities recommend that residents:
• Do not move plants or branches outside their area.
• Regularly inspect trees for yellowing leaves or unusual fruit.
• Report sightings of Asian citrus psyllids or suspicious symptoms.
• Allow agricultural inspections when requested.
Additional information about HLB prevention and reporting procedures can be found at https://californiacitrusthreat.org , https://ipm.ucanr.edu/agriculture/citrus/huanglongbing/#gsc.tab=0 , and https://ucanr.edu/site/asian-citrus-psyllid-distribution-and-management .
UC Agriculture and Natural Resources shares science-based practices across California to improve lives statewide through research and outreach initiatives (https://ucanr.edu/). The organization maintains nine Research and Extension Centers as living laboratories within diverse ecosystems throughout the state (https://ucanr.edu/). UC ANR operates offices in all 58 counties alongside its research centers (https://ucanr.edu/) and applies University of California expertise to support communities through collaborative efforts focused on farming methods, environmental conservation and wildfire protection (https://ucanr.edu/). Glenda Humiston serves as vice president of UC Agriculture and Natural Resources (https://ucanr.edu/).
“Experts from the University of California Division of Agriculture and Natural Resources (UC ANR) have developed research projects and extension programs focused on monitoring the Asian citrus psyllid vector insect, integrated pest management strategies, and educating farmers as well as communities about how to prevent disease spread,” according to UC ANR representatives.