A Butterfly and its Bush

Butterfly bushes are considered noxious weeds hereabouts. We have one that’s blocking the Sun in our front yard. When I returned from a bike ride this morning, I saw a butterfly sipping nectar from its namesake plant. I saw a different species of butterfly on the plant when I went out to get the mail, but didn’t have my phone with me. I don’t know what variety of butterfly this is. My nephew, the amateur lepidopterist, needs to weigh in.