Papilio maraho
The broad-tailed swallowtail (Papilio maraho) is endemic to Taiwan and a category I protected butterfly. Wingspan is 9-12 cm. The hindwings have two black veins that cross the broad tail extensions. A new and independent genus in East Asia, Agehana, was announced by Professor Shōnen Matsumura. Its sister species, Agehana elwesi, is distributed in China. In the past, the broad-tailed swallowtail was considered closely related to the swallowtail butterflies of the subgenus Chilasa, which are endemic to Asia. However, it was recently confirmed based on molecular characteristics (mitochondrial DNA sequencing) that its sister group is the Pterourus subgenus of North America. The two are very similar in terms of larval morphology and preference for host plants. Based on molecular dating, their ancestors came from North America, arriving in Asia (East Asia) via the Bering (Strait) land bridge around 18 million years ago during the early Miocene epoch, at the peak of warming. Larvae feed on the Taiwan Sassafras tree, which is also rare and classified as endangered. It is listed as a near-threatened species in the International Union for Conservation of Nature (IUCN)’s Red List of Endangered Species.
