Jim. three reference books and umpteen pictures on the net and I still have not figured out what it is. Looks like a European day-flying moth in shape, but not in color. I keep looking when I have some extra time, that's one of those things which I can worry to death, LOL.

I have no idea what that insect is either. But by looking at the holes in the plant, it seems it is built to go deep into the brussels
sprouts and that is not easy to do.
I wonder if it lays it's eggs in there or it is there, looking for food?

This is a cabbage moth. A couple million of them were in my garden this past summer, creating problems for me with my sprouts and broccoli. I got fed up with picking off the larva, I pull all the plants and destroyed them. I hope that this frigid weather will help to reduce their return.

I did lots and lots of looking and could not discover a thing as to what this one is.

I am not fond of cabbage moths either. They live in Germany too and it was my job as kid to pick off and kill the eggs and caterpillars, eek!