Tree Pest and Disease Alerts

Golden Spotted Oak Borer Infestation

The goldspotted oak borer is a pest new to southern California that can kill mature trees. This insect aggressively attacks three oak species with repeat attacks occurring over several years. It is contributing to the on-going oak tree mortality occurring on federal, state, private, and Native American lands in San Diego County and has the potential to kill native oak species throughout California.

Learn more from the University of California Agriculture and Natural Resources.

Asian Citrus Psyllid

All of Los Angeles, Orange, Ventura and Imperial counties as well as parts of San Bernardino, San Diego and Riverside counties are under temporary state emergency quarantine by the California Department of Food and Agriculture (CDFA) for the Asian citrus psyllid and the deadly disease it spreads – citrus greening disease also known as Huanglongbing (HLB) or yellow dragon disease. This quarantine regulates the movement of the trees and fruit of citrus and closely-related plants. More information at:

Federal, state and county officials are working with growers to implement the quarantine and hopefully prevent the spread of the Asian citrus psyllid in California.

For regulatory information regarding the movement of trees and tree parts (wood, fruits, rootstock, leaves, seeds, scion wood), contact the U.S.D.A. State Plant Health Director’s office at (916) 930-5500.

You can download a free app (for iPhone, iPad, iPod touch) to report findings and have instant access to the insect and disease descriptions.