In the definitive modern academic work on Ohio butterflies, Butterflies and Skippers of Ohio (1992), the authors have this to say about the Cloudless Sulphur, Phoebis sennae: "...it rarely reaches Ohio."
Not anymore. These large, beautiful butterflies that look like flying lemon wedges have become quite regular, their numbers definitely increasing. Variable numbers occur every year of late, and sometimes big numbers. Their common host plant is Wild Senna, Senna hebecarpa, and Cloudless Sulphurs regularly now reproduce here where the plant occurs.
John Pogacnik, who lives on the shore of Lake Erie in Lake County, gets scores of butterflies in his yard. To encourage butterflies, John has planted flora that are attractive to them, including Wild Senna. With great results, as we'll see.
The following series of amazing photos were taken by John in his yard recently.Gorgeous Cloudless Sulphur. This is a male. These are massive in-your-face buttery-colored sulphurs tinged with green. WAY bigger than the common Clouded Sulphurs that one sees everywhere.John's amazing shot of a pair, male above, female below. They are preparing to make more Cloudless Sulphurs.
The result of their coupling: an egg laid on a Wild Senna plant in John's yard. As he says: "plant it and they will come".
Eventually the egg hatched into this resplendent yellow-striped lime green caterpillar. After a period of fattening on the leaves of senna, it will transform into one of the lemon-yellow adults.
This species is one to watch. There seems to be a clear increase in southern/tropical butterflies (and dragonflies) north. Cloudless Sulphurs' normal range is the Gulf states and south into Central America. Their northward expansion is telling us something about the environment.
Thanks to John Pogacnik for providing these wonderful photos.