Distribution

Goldspotted Oak Borer (GSOB) infestations have spread throughout San Diego County since it's discovery in 2008. Satellite GSOB infestations were identified in Riverside County (2012), Orange County (2014) and Los Angeles County (2015). A second satellite infestation was discovered in south east Orange County in 2017. The latest GSOB satellite infestations were found in San Bernardino County (2019, 2020). All of these satellite infestations are believed to have occurred due to people transporting GSOB-infested firewood from known infested areas.

The California Board of Forestry and Fire Protection originally declared a Zone of Infestation (ZOI) for Goldspotted Oak Borer (GSOB) on September 12, 2012. This was an official and formal action to recognize GSOB as a threat to California’s forest and woodland resources and exhibits leadership in the effort to combat GSOB while providing the public with important information. The ZOI has since been expanded to include new areas of infestation and areas with increased risk to host oak trees. Maps of the current ZOI, by region and counties, are below. 

Maps courtesy of Kim Corella at CalFire

GSOB Zone of Infestation (ZOI) Showing the GSOB Distribution in
San Diego, Riverside, Orange, Los Angeles and San Bernardino Counties

Maps: (select and click)

• GSOB Zone of Infestation in Southern California
• GSOB Zone of Infestation in San Diego County
• GSOB Zone of Infestation in Riverside County
• GSOB Zone of Infestation in Orange County
• GSOB Zone of Infestation in Los Angeles County
• GSOB Zone of Infestation in San Bernardino County

GSOB Zone of Infestation: San Diego County
(2019) Note - Since 2019, the majority of San Diego County has been designated a GSOB Zone of Infestation. There were no changes in 2020.

GSOB Zone of Infestation: Riverside County
(2020)

GSOB Zone of Infestation: Orange County
(2020)

GSOB Zone of Infestation: Los Angeles County
(2020)

GSOB Zone of Infestation: San Bernardino County
(2020)