Megalographa biloba
When one of these flew in through my Victoria window in 1995 it had apparently not previously been recorded in western Canada, though it is widespread enough in most of North America and had presumably merely escaped attention here previously. The following year I found a caterpillar feeding on Comfrey Symphytum officinale immediately outside my window, but I just assumed it was a more familiar species and I didn't bother to photograph it. How I regretted that when the moth emerged a few weeks later and it proved to be biloba! The silvery mark on the wing looks as though it really is metallic; it is highly reflective at certain angles. The moth was formerly known as Autographa biloba.