The goldspotted oak borer beetle, Agrilus auroguttatus, poses a major threat to oak trees in California. Native to southeastern Arizona, the beetle was first collected in southern California in 2004 and has since killed nearly thirty thousand oak trees in San Diego County. Researchers believe that the goldspotted oak borer was likely introduced into southern California on oak firewood. Heightened awareness regarding the danger of moving this and other pests on firewood may help to slow the spread of the beetle within California. Nonetheless, it was discovered in a second county (Riverside) in 2012.
Goldspotted oak borer larvae feed beneath the bark of oaks in the red oak group, and damage the vital tissues of the main stem and larger branches. Generally, a few years after initial infestation, trees decline and die from the damage caused by multiple generations of this aggressive beetle.
Forest Service researchers are working with other government agencies at the state and local level as well as academic institutions to address this threat to oak trees. To learn more, contact Steven Seybold, a Research Entomologist specializing in the study of bark and wood-boring beetles, at the US Forest Service or UC Davis.
Find research publications about the goldspotted oak borer on Treesearch.
- Pest Notes: Goldspotted Oak Borer (University of California Statewide Integrated Pest Management Program, 2013)
- Field Identification Guide: Goldspotted Oak Borer (University of California Statewide Integrated Pest Management Program, 2011)
- Pest Alert: Goldspotted Oak Borer (USDA Forest Service, 2008)
- California Oaks Threatened by Invading Wood Borer (The Western Front, Newsletter of the Western Integrated Pest Management Center, 2012)
- Goldspotted Oak Borer Threatens California Oaks (CAPCA Advisor Magazine, 2011)
- For more information, visit the Statewide Integrated Pest Management Program or the Goldspotted Oak Borer Steering Committee.