The above are now to be found all over my passiflora vines. I was so happy to see them finally arrive. They are quite late this year, I don't know why. My guess is that the really cold winter we had set them back some. These spiny, ugly, and scary-looking caterpillars are totally harmless to people, but they "passionately" eat at maypop vines.
It's amazing that those ugly cat's will eventually turn into the above beautiful and plentiful butterfly. This picture is from last year. I have yet to get a decent picture this year, though I've tried. Tithonias ("mexican sunflowers") are among their favorite nectar sources, along with buddleias ("butterfly bush") and zinnias. If you want plenty of these beauties, you really should have at least one passiflora vine planted somewhere in your yard to go along with nectar sources.