Goldspotted Oak Borer Found in Fallbrook

Deadly pest threatens local oak trees; infested firewood transported into other areas are of paramount concern


Thursday, May 24th, 2012

Fallbrook Bonsall Village News

Andrea Verdin

Staff Writer



Fallbrook’s iconic oaks might be in grave danger of infestation and destruction.


According to Jess Stoffel, vegetation manager for the County of San Diego, the goldspotted oak borer (GSOB), or agrilus coxalis, was first detected in the county in 2004 during a trap survey for invasive tree pests.


“In 2008 this borer was linked to elevated levels of oak mortality ongoing in San Diego County since 2002,” he said in an email to community leaders. “Its existence in California may date back to as early as 1996, based on examinations of previously killed oaks.”


GSOB, which is a native to Arizona and Mexico, was likely introduced into southern California via infested oak firewood. Roger Boddaert, known as “the tree man” of Fallbrook, stated that he is “very much aware” of this pest and other infestations.


“Primarily, there are four main species the borer is attacking, including our indigenous coastal California Live Oak,” said Boddaert. “I recently attended a conference at the Pechanga Government Center on the borer and other native oak concerns. There was a large attendance from the US Forest Dept., UC Davis and Riverside, and all the major players in this major concern.”


It is a serious pest of coast live oak, Quercus agrifolia; canyon live oak, Q. chrysolepis; and California black oak, Q. kelloggii in California and has killed more than 20,000 trees across 620,000 acres.


Boddaert stated that the GSOB have been identified in Julian, southern San Diego County, and primarily in the mountain ranges.