Environment & Science

Tree-killing fungus found in Riverside County

File: Dried leaves fall among green poison oak as fall-like colors appear in summer in southern California's predominantly chaparral habitat on July 19, 2007 west of Mount Wilson in the San Gabriel Mountains, north of Pasadena.
File: Dried leaves fall among green poison oak as fall-like colors appear in summer in southern California's predominantly chaparral habitat on July 19, 2007 west of Mount Wilson in the San Gabriel Mountains, north of Pasadena.
David McNew/Getty Images

A fungus that has killed trees throughout Southern California has turned up in Riverside County.

The Desert Sun of Palm Springs says the Fusarium fungus has been found near Norco. Agriculture officials say it could threaten oaks and the county's lucrative avocado crop.

The fungus is carried by a beetle that bores into trees and causes what's known as Fusarium dieback.

Akif Eskalen, a plant pathologist of the University of California, Riverside, says the fungus has been found on more than 117 different plant species in Southern California. It's infected both ornamental street trees and backyard trees.

Eskalen says he first detected in Los Angeles County last year but the fungus has spread to Orange, San Bernardino and San Diego counties.