I get to see them two or three times a week when I walk through a nearby park. The park has several areas where there are native Pawpaws. There are many different types of Pawpaws and supposedly the zebra swallowtails tend to prefer the ones that are native to each area. The Triloba grow well up north and even here, in Central Florida. I have three or four, the largest is about 15ft tall now and this year they produced a bunch of fruit--but they have attracted no butterflies.
It has been very frustrating. These are beautiful butterflies and I would love to be able to host some. I have planted a bunch of the native Pawpaws, but they grow very, very slowly--maybe three inches a year it seems. I believe there are eight different types of Pawpaws in Florida. Other than the Triloba the parviflora is the most common in northern Florida. In Central Florida we have ones that grow in the sand hills. I think the names are reticulata and obovata. They have very deep tap roots, so they are almost impossible to dig up and transplant. I only know one person who grows them in our area, and, again, they grow very slowly.
Anyway, they are very beautiful butterflies and a joy to see in flight.