Sacramento – At its September 12, 2012 meeting, the California Board of Forestry and Fire Protection (Board) adopted a Zone of Infestation within San Diego County for the Goldspotted Oak Borer (GSOB) based on a recommendation made by CAL FIRE Chief Ken Pimlott, California’s state forester.

The Board’s adoption of a GSOB Zone of Infestation is intended to raise awareness of the pest and reduce the potential for its spread outside of San Diego County. Establishment of the Zone will likewise support ongoing multi-partner collaborative efforts toward GSOB prevention, containment, control, and remediation.

The GSOB was first identified in 2002 in San Diego County and thus far does not appear to have expanded its occupation elsewhere in the state. The insect is causing mortality in healthy, mature coast live oak, canyon live oak, and California black oak trees. It is estimated that approximately 80,000 oak trees have been killed in San Diego County since 2002 as a result of the GSOB infestation. The GSOB continues to spread within the county causing significant damage and mortality to oak species.

To help prevent the spread of GSOB, it is critical that all firewood and cut wood not be removed and transported outside of the Zone of Infestation. Covering cut oak with plastic tarpaulins can help contain the insects. Mulching, soil aerations, and fertilizing may increase oak health and delay tree mortality.Removing infested trees, and properly managing the wood disposal, can reduce localized infestation and help minimize the spread.

The GSOB Zone of Infestation adoption is supported by the United States Forest Service, California Forest Pest Council (Southern California Committee), San Diego County Agriculture Commissioner, and California Department of Parks and Recreation.

More information on the Goldspotted Oak Borer can be found at the University of California Cooperative Extension GSOB website at:

Source: California Board of Forestry and Fire Protection

Have something to say? Share your thoughts with us in the comments below.