Hi There,

Thanks for the message. Did you save the beetle and/or did you take any photos of it? If so, please send them my way for species confirmation.

The California Root Borer beetle (Prionus californicus) is a somewhat common beetle in our area. They are widely distributed in western North America from Mexico to Alaska. The majority of their three to five year life cycle is spent underground as larvae, feeding on the roots of deciduous trees and shrubs, as well as some conifers, blackberries, and agricultural crops such as hops and grape vines. Adults emerge from pupae in the soil from June to early August and do not feed. The beetles fly at night in search of mates and are often attracted by lights which is probably why it entered your house.

This is a serious pest of fruit trees and hops, so it can be an issue if you have any orchards. It doesn't appear to be as big of an issue in our native conifers and hardwoods (except cherry). I've linked two articles below, the first from the OSU pest mgmt handbook with chemical and manual removal recommendations (though I would recommend manual removal only). The second, an article from Washington State University that gives a good overview of the beetle, including mgmt options (again, manual removal seems best).

1. https://pnwhandbooks.org/insect/agronomic/hop/hop-prionus-beetle

2. https://treefruit.wsu.edu/crop-protection/opm/california-prionus/

Thank you kindly,

Lorelle