ABSTRACT: The genus Taiwanolepta Kimoto, 1989 (type species Taiwanolepta babai Kimoto, 1989) is proposed as a junior synonym of Sikkimia Duvivier, 1891. Sikkimia species from Taiwan form a group characterized by the reduction of their hind wings. Most of them cannot be distinguished using external morphology, except by the structure of last two antennomeres in males. Diagnoses are made by using distribution, aedeagal, and gonocoxal morphology. The group includes one previously described species, Sikkimia babai (Kimoto, 1989), comb. n., and four new species, Sikkimia meihuai sp. n., Sikkimia sufangae sp. n., Sikkimia tsoui sp. n., and Sikkimia yuae sp. n. Speciation models, supporting the high diversity of Sikkimia species in Taiwan, are discussed. Sikkimia metallica Jacoby, 1903 and Sikkimia tamra Maulik, 1936, both from southern India, are transferred to the genus Cerophysa Chevrolat, 1836.
