“We’ve found four more trees positive with goldspotted oak borer infestation,” said Greg Bratcher, unit forester for Cal Fire on the Hill. The newest trees confirmed with GSOB are in the Saunders Meadows, High Castle and Marion View areas.

“I’m pleased that so far we’ve only found four additional trees,” said Kevin Turner, GSOB coordinator for University of California Agricultural and Natural Resources at UC Riverside. “But that doesn’t mean there are not more.”

With fall approaching, the leaf color will be less apparent. But both Bratcher and Turner have said many oak trees are displaying stress from the drought, which makes the infected trees more difficult to identify. While not infected, the lack of water may make them more vulnerable.

“Typically trees in stress will show the effects at the end of summer and fall when the water limitations are at their greatest,” Bratcher said.

While no scientific research has connected drought-stressed oaks with greater susceptibility to GSOB infestation, Turner said the regional GSOB inspectors are finding that the infestation in San Diego County is spreading since the drought began.

With the confirmation of at least 21 trees infected, Turner said it is now just as important to limit oak firewood export from Idyllwild as it is to limit its import.

“We need to be extremely cautious and careful about taking wood out of the community now,” he advised. “But we could still bring the beetle here.”

At this point, identifying GSOB’s presence on the Hill has been limited to oak trees on private property. No infested trees have been found in the national forest, according to Kayanna Warren, San Jacinto Ranger District forester.

Both men praised the Mountain Communities Fire Safe Council and the Idyllwild Garden Club’s volunteers, who weekly investigate reports of possible infected trees.

The GSOB hotline number is 951-659-8328.