Subject: Flat Faced Longhorn Beetle
Location: Dorrington, CA (Sierra Nevada)
September 11, 2014 6:42 pm
Based on what I’ve seen here and elsewhere, I believe this to be a Flat Faced Longhorn Beetle. This photo was taken in early July, 2012 at our cabin near Dorrington, California, elevation about 5,000 ft. We don’t see these every year, but 2012 we saw at least a half dozen of these large (two-inches of body, four inches total), intrepid beetles on our property. They don’t scare easily, and can be picked up and moved around (which I did so he wouldn’t get smooshed by an errant foot). I don’t know why they show up some years and not others, but they are always startling to see them crawl over a railing a foot from your face.
Signature: Typeaux — SF Bay Area, California
You are correct that this is a Flat Faced Longhorn Beetle in the subfamily Lamiinae, and we can be even more specific. It is a Whitespotted Sawyer, Monochamus scutellatus. According to BugGuide: “Two-year life cycle. Larvae excavates galleries in coniferous trees, often after they are damaged by a fire, storm, etc. Common hosts are: Balsam fir, spruces and white pine.” Perhaps their sporadic appearances are connected to some event that affected the trees.