Taiwan’s Only Geometrid Moth

Taiwan’s only geometrid moth
A close look at Taiwan’s only geometrid moth.

Yesterday I breezed through the small town of Èrshuǐ 二水 in southern Changhua 彰化 to scope out some historic sites on my list. One of these sites, the old Ershui Public Hall 二水公會堂, is located next to a wide expanse of unkempt meadowland, evidently a breeding ground for Taiwan’s only geometrid moth. There were hundreds of brightly-colored, iridescent moths flitting around the overgrown ruins—and many more locked in an embrace on whatever flat surfaces could be found. After coming home last night it didn’t take long to puzzle out the name of this species of moth: Milionia basalis pryeri, a subspecies of Milionia basalis only found in Taiwan and southwestern Japan 日本, particularly Okinawa 沖縄. There appears to be no English common name but in Chinese it is generally known as chéngdàizhīchǐ’é 橙帶枝尺蛾; roughly “orange-banded moth”.

Geometrid moths mating in Taiwan
How new moths are made!
Another look at Taiwan’s geometer moth
Smartphone version of the same moth seen above.

Naturally these strikingly beautiful moths have attracted the attention of Taiwanese bloggers; for more photos and info in Chinese try here, here, and here. More basic info can also be found here, here, and here (in Chinese) and here (Japanese). Finally, if you’re interested in moths, I also wrote a short post about bumping into one of the world’s largest moths here in Taiwan.