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.

The genus Magnificus Yan, 2000 was originally established to include M. jiuzhiensis Yan, 2000 and M. zhiduoensis Yan, 2000. Here we also include the species M. bouvieri (Oberthür, 1913) comb. n., M. dirschi (Bang-Haas, 1939) comb. n., M. miniatus (Chu & Wang, 1985a) comb. n., M. regius (Staudinger, 1896) comb. n., and M. roseus (Oberthür, 1911) comb. n. Monophyly of Magnificus is supported by the shared presence of a unique shape of the tergosternal sclerite in the anterio-abdominal region and pseudoteguminal arm in the male genitalia. We also provide evidence for the inclusion of Magnificus and the northern Eurasian genera Hepialus Fabricius, Pharmacis Hübner, Triodia Hübner and Zenophassus Tindale as members of a larger monophyletic group supported by the shared presence in the male genitalia of a deep U-shaped medial notch in the posterior margin of the saccus and an expanded triangular flange at the lateral corners of the notch. The reciprocally allopatric distribution of Magnificus and its probable sister group is consistent with each originating locally by vicariance over different parts of a widespread ancestral range. This divergence may be the result of tectonic uplift in central Asia.

Two species of Endoclita C. &. R. Felder, 1874 from Taiwan are evaluated for their taxonomic status: Endoclita meifenga Buchsbaum & Grehan sp. n. is described as new for a unique male from the central mountains of Taiwan, and E. kosemponis (Strand, 1916), stat. rev. is elevated to species status. We show that the forewing markings and genitalic characteristics of E. meifenga sp. n. distinguish this species from all other Endoclita. The external appearance of E. kosemponis is similar to E. sinensis (Moore, 1877) but the two species show distinct differences in the male and female genitalia. Preliminary comparison of E. sinensis from Taiwan and Japan suggests they represent more than one species. A sample of the COI gene was sequenced for E. meifenga sp. n. and the primary types of E. meifenga sp. n. and E. kosemponis sp. n. are illustrated here for the first time. The taxonomic status of the non endemic Taiwanese E. davidi (Poujade, 1886) and E. sinensis needs future evaluation.

The species Hyblaea solomonensis Buchsbaum & Chen, sp. n. is described from the Solomon Islands. The species is to be placed in the Hyblaea constellata Guenée, 1852 - species group due to its similarity in the external morphological features, as well as in the genital structures. The new species differs from all other species in this group.