You've dons a great job of getting this guy isolated so we can see all his details. I've seen them on my milkweed before but they always seem to be blocked by other branches or grasses.
Good news! I had tried to grow Milkweed in the area that separates my yard from the neighbors but it never took. Lousy soil is probably why. But I would have loved to raise Monarchs there if I could have. Excellent shot!
