Jon Sullivan> Dark Underwing Wainscot
I can see a dark underwing waistcoat making sense but what’s a wainscot? You Mastodon folk might have already known this but I had to look that up. Turns out it’s wood panelling that’s used to embellish the lower parts of indoor walls, typically in older houses.
It looks like it’s the raised veins on the forewings of the moths that got them the Wainscot common name.