Gold Spotted Oak Borer

The goldspotted oak borer (GSOB), Agrilus auroguttatus is a flat headed borer that poses a significant threat to oak trees. The pest is native to southeastern Arizona and was first identified in California in 2004 in San Diego County. It has since been killing trees throughout San Diego, Los Angeles, and Orange Counties in forests, parks, and residential landscapes.

GSOB larvae feed beneath the bark near the vascular tissue in the older, mature trees.  Trees die after several years of injury inflicted by multiple generations of the beetle, causing significant economic, ecological, cultural, and aesthetic losses to the region. GSOB poses a major threat to susceptible oak species (Coast Live Oak, Canyon Live Oak, and California Black Oak) throughout California and southern Oregon. Currently there are no effective tools for protecting trees once infestation occurs.

We have placed GSOB traps, in accordance with USDA and CDFA, throughout Santa Barbara county focusing on placing them in campgrounds where infected firewood may introduce GSOB. Our hope is that if any GSOB are in our county, that the traps will catch them during the flight season May-September. More info can be found here: http://ucanr.edu/sites/gsobinfo/

Mature GSOB to scale.  Photo UC Cooperative Extension.

Lateral view of GSOB.  Photo CISR- Center for Invasive Species Research, UC Riverside.

D-shaped  exit holes (3-4 mm).  Photo UC Cooperative Extension.

Live Oak being removed after succumbing to GSOB in Southern CA.  Photo CISR- Center for Invasive Species Research, UC Riverside.

 GSOB trap placed in Santa Barbara County for the 2019 trapping season.  Photo-Mel Graham, Santa Barbara County Ag Commissioner's Office.