A new species Endoclita atayala Buchsbaum & Hsu sp. n. is based on a single female specimen collected at light in the high mountains of northern Taiwan. Comparisons with all other Endoclita (C. & R. Felder, 1874) species confirms that E. atayala sp. n. exhibits distinctive and unique wing pattern characteristics and probably has a sister group relationship with E. crenilimbata (Le Cerf, 1919) of southeastern China and illustrated here for the first time, and E. nodus (Chu & Wang, 1985) of northeastern China. The species diversity of Taiwanese Hepialidae is described and the biogeographic implications of the E. atayala sp. n. relationship for the origin of endemic species in Taiwan are reviewed.

Larvae and females of two Stenopsyche species, S. formosana Kobayashi and S. drakon Weaver, are described for the first time. They were associated with the adult male through mitochondrial DNA sequence comparisons. The male of S. formosana, which has been recorded as Stenopsyche banksi Mosely from Taiwan, is redescribed. The males of S. formosana and S. banksi can be distinguished from each other by the shape of segments IX and X, and endothecal spines. In larvae, S. formosana and S. drakon are distinguishable from each other and from other known species by the combination of different dark marking patterns and shapes of no. 18 setae of the head, and by the shapes of forecoxae. The larval morphology of S. formosana and S. drakon suggests that the phylogenetic relationships based mainly on male genitalia in the genus Stenopsyche should be reconsidered.

The phryganeid caddisfly Eubasilissa signata Wiggins, 1998 was originally described based on a single female specimen from Korea, and no other information on the species was available. Here we record an additional five male and five female specimens of E. signata from Taiwan and describe the male morphology for the first time.Based on morphological differences with other Eubasilissa species, E. signata should be regarded as a separate species and also not a member of the "tibetana" species group. A 658-bp fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene of the new specimens of E. signata is provided as a DNA barcode.