“Deadly Goldspotted Oak Borer Threatens Majestic Oak Forests in Southern California”

In a rugged Santa Clarita canyon, the discovery of dead trees pockmarked with D-shaped “exit holes” signaled a deadly threat – the goldspotted oak borer. Ron Durbin, forestry division chief for the Los Angeles County Fire Department, described the beetle as “just like a cancer” that has spread across Southern California since its discovery in 2008 in San Diego County, where it has decimated over 80,000 trees.

The presence of the goldspotted oak borer in East Canyon, along with nearby Rice and Whitney canyons, just 14 miles from the oak-rich Santa Monica Mountains, has raised alarm bells. The beetle was also recently detected in a new area of Silverado Canyon in eastern Orange County.

A coalition of fire officials, land managers, local representatives, and pest experts across Southern California are working to slow the spread of the goldspotted oak borer, acknowledging that eradication is not possible. The stakes are high, with roughly 600,000 coast live oaks in the Santa Monica Mountains at risk of being lost, leading to the loss of shade, wildlife habitat, and increased fire hazards.

The L.A. County Board of Supervisors passed a motion on May 7 to explore declaring a state of emergency and finding funding for additional county Fire Department staff to address the problem. The motion also calls for drafting regulations on the movement of firewood, which is a key vehicle for the beetle’s long-distance spread.

The goldspotted oak borer, adorned with six gold spots on its back, targets oaks exclusively, including the coast live oak, canyon live oak, and California black oak. The beetle, native to Arizona, likely traveled to California via firewood and has since spread rapidly across the state.

Efforts to combat the goldspotted oak borer include reporting infested trees, burning firewood where it is purchased to prevent the spread of pests, and volunteering with organizations like Earthroots Field School to help tackle the infestation. Various treatment methods, including systemic pesticides and experimental nontoxic limewash, are being tested to combat the beetle.

Researchers are exploring the use of prescribed fire based on indigenous land management practices to manage the oak borer infestation. Lessons learned from this battle could inform future strategies for dealing with invasive pests. As climate change continues to impact ecosystems, proactive measures and legislative actions may be necessary to address the threat of invasive species effectively.