Quwatanabius chiaw (Smetana, 1995) (Figs. 1–6)

Material examined. TAIWAN: 1 male, Taichung City, Daxue Mt. Forest Trail 31.7k [LṞƜẇae 31.7k], Heping Dist., 24.2255, 120.9764, alt. about 1950 m; 28–11–2019, leg. F. S. Hu (in dead wood) / Quwatanabius chiaw (Smetana, 1995), Det. By F. S. Hu , 2019.

Description. Male. Body (Fig. 1) matches the species description of the female (Smetana 1995). Sternite VIII (Fig. 2) with rather narrow, deep, triangular medioapical emargination. Sternite IX (Fig. 3) with rather narrow, U-shaped apical emargination, with one strong and long seta on each side of the emargination, plus two longitudinally arranged strong and long setae near the apex of each lobe of the sternite. Tergite X (Fig. 4) with a pair of short setae in the middle; with rather narrow, U-shaped apical emargination with two to three pairs of strong and long setae and a pair of rather short longitudinally arranged setae on each side of the emargination. Aedeagus (Figs. 5–6) relatively small; median lobe subparallel-sided in middle portion, anteriorly conically narrowed into acute apex. Paramere small, trapezoid-shaped, with a broad medioapical emargination; subtriangular-shaped in lateral view. Internal sac with two strip-like sclerites, each sclerite with two sizeable teeth and a blunt protrusion.

Female. See Smetana (1995).

Diagnosis. Quwatanabius chiaw is similar to Q. flavicornis but can be distinguished by the following characters: pal- er, rufo-testaceous pronotum; relatively shorter elytra; absent pale apical seam of palisade fringe on tergite VII; broader apex of median lobe (in ventral view); simpler structure of internal sac, where lateral protrusions are not visible in ventral view.

Bionomics. Smetana (1995) was not able to report the bionomics when he described this species. Additional specimens in Smetana (1996) were collected by sifting rotting, moist twigs, logs and bark along fallen trees. The specimen in this study was collected from the inside of a large and moist, strongly decomposed piece of fallen dead wood in primary, evergreen forest. According to the available locality data, the species is found on high elevations (approximately 1900 m or higher).

Comments. The hind wings of this species are quite short and probably non-functional. The absence of the apical seam of palisade fringe on tergite VII also suggests this species is flightless. Quwatanabius chiaw is the only species considered to be flightless in this genus at the moment. Hence, we suggest that this is an endemic species with restricted distribution in the mountainous areas of central Taiwan.

Distribution. The species is known from central Taiwan (Nantou County and Taichung City).