This was behind a drop ceiling in a basement, and it was the ONLY board that exhibited damage. 2x lumber was installed on top of joists, and then plywood was installed on top of these “sleepers.” One of the horizontal boards had really wide tunneling. Only showed up on about 5 feet of the length of the board and it was no where else on the entire ceiling framing. No dust or frass or anything around it or under it. I’m wondering if it was done before install, by what I’m not sure. It’s almost the size of carpenter bee tunnels. Home is built 1980 in NJ, traditional 2x framing on a concrete block foundation wall. Rim joists and sill plates showed no signs of any WDI.
Anyone see this before or have any idea what caused it? Trying to figure out if it needs treatment.
Looks like pre-mill damage… As in, it was in the wood before being used for the house. Not sure why someone would use that piece. The galleries were cut open when the wood was sawn. No insect I know of makes markings like that. Maybe an angry woman’s fingernails?
Cerambycidae beetle (Old House Borer).
The reason for the nickname is the larval stage that creates the damage take 3-5 years to mature, sometimes more.
So… by the time there’s any recognizable damage generations have passed, thus an old or older house.
I remember one time in an attic I stepped on this one beam & it split open.
Shot the flashlight over & this giant alien type white worm was wiggling around.
Scared the crap out me me at first sight.
They do have the ability to totally destroy stuff like yellow pine. It takes a long time though.
