Rarest swallowtail butterfly

The world's rarest species of swallowtail butterfly (family Papilionidae) is the Ceylon or Sri Lankan rose Pachliopta (=Atrophaneura) jophon, which is endemic to the island of Sri Lanka (formerly Ceylon), and is categorized as Critically Endangered by the IUCN (the only swallowtail species so categorized). Its grave state is the result of habitat destruction, and although precise numbers of specimens are not currently confirmed, it is presently confined entirely to the rain forests of the central hill country in Sri Lanka's southwestern portion.

Predominantly black and white but with a series of red spots edging the upper side of its rear wings, this beautiful species was formerly classified as a subspecies of the crimson rose P. hector, native to India, and not deemed to be endangered, but it is nowadays considered sufficiently distinct taxonomically to warrant recognition as a valid, separate species in its own right, thereby making its perilous state all the more alarming.