We're all under great stress here due to the drought. All of the Sierra Foothills contain a variety of native oaks. My signature oak out back is a blue oak. I'll post another challenge tomorrow about other damage that has shown up.
Do you think the drought is why you have this guy? A bit of moving out of the dried out places looking for anything fresh and green? Or has it always been a part of your landscape in CA?
According to the article, they have always been part of the oak tree habitat, even tho they are not "good" beetles. Let me tell you, it was at least 2.5 inches in length and was a female. Before I knew what it was, I tossed it into a hedge of rosemary.
I saw a downy woodpecker yesterday and wondered if stress on trees and resultant bug infestations might benefit the woodpeckers.
Then, I thought of those sapsuckers in California and the damage they cause. If this heat is a continuing trend, I'd sure prefer it doesn't draw those pests north.