Actually, it is the Zebra Swallowtail caterpillars that love (feed on) Pawpaw. The Pawpaw plant, that is, not Pa Pa the granddad. Even if he acts like a plant.
The scientific name for this butterfly is Eurytides marcellus, named by Cramer in 1777. The Zebra Swallowtail is in the Papilionidae family.
You may have noticed in the picture above, that it appears as if the Zebra Swallowtail is eating dirt. Close. It is sipping moisture from the sand. The photo was taken on the banks of Lake Mitchell in Chilton County, AL- there were about 30 of these butterflies feeding there at the time that I made the photo. According to http://www.butterfliesandmoths.org/species?l=1353, these butterflies also "drink nectar from flowers including blueberry, blackberry, lilac, redbud, viper\'s bugloss, verbena, dogbane, and common milkweed." But, I just usually see them drinking from the sand- which isn't as picturesque as sipping nectar from the flowers.