Imperial Valley on the watch for citrus greening disease

Wax droppings of the Asian Citrus Pysillid

IMPERIAL VALLEY — A disease deadly to citrus trees called Huonglangbing, also known as HLB, or citrus greening disease, was discovered in Riverside County July 10. Riverside is now the third district in the state of California to have been affected by HLB.

HLB symptoms in citrus include asymmetrical, blotchy yellowing of leaves, small asymmetrical fruit with bitter juice that easily falls off of the tree and eventually, death of the tree. HLB is carried by the Asian citrus psyllid, an aphid-sized pest that came to California in 2008.

According to the Citrus Disease and Prevention Program, California’s citrus industry is valued at more than $2.5 billion and encompasses large and small farms throughout the state. Commercial citrus growers are responsible for maintaining healthy citrus trees, which includes applying treatments to protect trees from the Asian citrus psyllid.

Carlos Ortiz of the Imperial Valley Agricultural Commission Office said since the first outbreak of the disease in San Diego in 2008, there have been no citrus infections reported in the Imperial Valley. However, that does not mean the commissioner’s office is not being vigilant, he said.

“It’ll be easier to manage if we can detect it as soon as possible,” said Ortiz. “It takes a group effort to contain and monitor for HLB.”

Survey methods for the citrus pest include visual inspections of citrus trees by CDFA and county field inspectors, “sweep netting” for insects, and the placement of yellow panel “sticky traps” in host trees and shrubs in citrus nurseries, commercial citrus-producing areas and residential properties throughout the state. Additionally, sticky traps are placed at California fruit packing houses, specialty markets, retail stores and airports that receive such produce from areas known to be infested with the aphid-like insect.

Once a tree has been infected, there is no cure, officials say. It will have to be fully removed and the rest of the trees inspected for infection. Currently, Los Angeles and Orange County are under a strict HLB quarantine following the discovery of the disease in residential trees.

The Imperial Valley currently has 6,500 acres of commercially-grown citrus. Citrus is also grown privately all over the Valley at residential homes. Ortiz clarified if cases of the disease are discovered in the Valley, the effect would be devastating.

When the Asian psyllid was discovered in Florida, there was no quick response since authorities were under the belief the insects did not carry HLB. However, months later, the disease was discovered in citrus trees and it was too late.

For residents who want more applicable information about the Asian citrus psyllid, HLB, and what can be done to help save California citrus, visit or call 1-800-491-1899.