Citrus tree owners in Riverside are being asked to examine their trees for Huanglongbing (HLB), a disease that attacks and kills at tree’s vascular system.
A fourth case of the condition was discovered in Riverside recently, on the same property where infected trees were first identified in 2017, according to a statement on the city’s website.
That discovery led to a quarantine and treatment program that remains in place.
“The most recent discovery of HLB, also known as citrus greening disease, marks the first new case [in Riverside] in two years,” the statement reads. “But it also emphasizes the point that the spread of the bacteria causing HLB remains a threat to citrus trees in Riverside and surrounding communities.”
Citrus greening, which is not a threat to humans, is carried by the Asian Citrus Psyllid. More than 1,300 trees in Los Angeles and Orange counties are infected with the disease.
There is no cure for the disease, which is spread by the Asian Citrus Psyllid when it moves from plant to plant. Typically, a tree declines and dies within a few years of being infected.
Citrus greening has dealt a lethal blow to Florida’s citrus industry since the condition was first detected there in 2005. It has cost citrus growers in the state an estimated $3 billion in revenue during that 14-year period, according to a University of Florida statement.