A Butterfly as Big as a Human Head on the Handrail... An Unwelcome Guest Appears in a Japanese Subway

Suspected Scented Swift Butterfly Individual Found
Habitat Confirmed Not Only in Japan but Also in Korea

A photo of a giant butterfly clinging to a subway handrail in Japan has been shared and is causing a sensation.

An insect presumed to be a butterfly sitting on a handrail inside a Japanese subway. [Image source=Capture from X (formerly Twitter)]

Recently, on X (formerly Twitter), a Japanese netizen posted a photo with the caption, "My heart almost stopped because there was a butterfly on the subway handrail." In the photo, a huge insect presumed to be a butterfly was sitting on the handrail inside a Japanese subway. Its size was so large that it occupied more than half of the handrail. The poster added, "It's unlucky to encounter a size that is hard to see even when walking outside, inside the subway. It was so crowded at every station that I couldn't escape." However, it is unknown how this butterfly got inside the subway.

One Japanese netizen explained, "The butterfly in the photo seems to be a 'Musk Swallowtail' (Sachangjebinabi)," adding, "It has poison in its body, so be careful." Other netizens reacted with comments such as, "Isn't that an eagle, not a butterfly?", "If it flies around inside the subway, it would cause panic," and "It's so huge." The photo was also shared on various communities in Korea. Netizens who saw it commented, "It looks more like a type of bird than a butterfly," "It looks pretty," "If it's that big, you should pay to ride the subway," and "The poster is amazing for not fainting after seeing that."

The butterfly in the photo is presumed to be a 'Musk Swallowtail.' The male is known to have a musk scent, which is how it got its name. Belonging to the family Papilionidae, the Musk Swallowtail is said to be seen flying slowly over plains and foothills during midsummer, from July to August. Its wingspan reaches 41 to 55 mm, making it a large butterfly. The butterfly in the photo appears slightly larger than other individuals and is yellowish, suggesting it is a female. The Musk Swallowtail can be found not only in Japan but also in Korea. It is known to be distributed across Korea, Japan, China, and Taiwan.