Novato arborists, property owners urged to watch for invasive beetle attacking oak trees

Agriculture officials in Marin County are alerting property owners and arborists to be on the lookout for a tiny invasive beetle that attacks oak trees, after the insect was detected last month in Novato.

The Mediterranean oak borer (Xyleborus monographus) is about one-eighth of an inch long and bores tunnels into stressed oaks, mostly valley oak but also other white oaks like Oregon white and blue oak, Marin agriculture officials said.