Phasmotaenia lanyuhensis

Phasmotaenia lanyuhensis is similar and closely related to P. sanchezi, the type species of the genus Phasmotaenia from the Philippines, but has a more robust body, relatively shorter mesothorax, larger head, and shorter antennae. Furthermore, female P. lanyuhensis have more prominently swollen mesothorax, shorter alae, and shorter subgenital plate. P. lanyuhensis was described based on four females and three males, including three mating pairs. Males measure 114–117 mm (4.5–4.6 in) and females 158–162 mm (6.2–6.4 in) in body length. They are slender-bodied insects with tiny or absent fore wings and short hindwings. Coloration varies from pale brown to dark brown to green. The hindwings are black in females and brown in males. The thorax is broadened in females and elongate in males. The legs are long and slender and bear numerous small serrations; the femora may have four dark brown bands in females. The head is smooth and much longer than it is wide. The eyes are small. The antennae are brown and have 23 segments. The egg capsule is 4 mm (0.2 in) long.

Phasmotaenia lanyuhensis is known from its type locality, Lanyu Island (Taitung County). It is very common on the island. P. lanyuhensis is the most northern Phasmotaenia species, otherwise known from the Philippines, Micronesia, New Guinea, and Fiji.