Yellow Swallowtail Caterpillar on Fennel

"Papilio machaon", the Old World swallowtail, is a butterfly of the family Papilionidae. The butterfly is also known as the common yellow swallowtail or simply the swallowtail. It is the type species of the genus "Papilio". This widespread species is found in much of the Palearctic and in North America.