Stenichnus (Stenichnus) taiwanicus Franz, 1985

Jałoszyński, Paweł, 2023, New species and new records of Eastern Palaearctic Stenichnus Thomson (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 5318 (3), pp. 363-381 : 370

Stenichnus (Stenichnus) taiwanicus Franz

( Figs 14 , 22 )

Stenichnus taiwanicus Franz, 1985: 94 . Redescribed by Jałoszyński (2004): 168.

Material studied. TAIWAN: 1 ♁, Nantou County, Dehuashe, Tuch Hsiang , 8– 11.04.2004, FIT, leg. T . Tsuru (cPJ); 1 ♁, Taichung County, Anmashan , 2225 m, 03.05.1990, leg. A. Smetana ( MHNG); 1 ex. , same data but 2230 m and 01.05.1990 ( MHNG); 1 ex. , Fenchihu , 1400 m, 04–06.1977, leg. J. & S. Klapperich ( MHNG) .

Distribution. Taiwan.

Remarks. In Taiwan, this species was collected together with S. bellulus at high elevations (over 2000 m) in mountainous areas. Jałoszyński (2004) mentioned features associated with punctures on the elytra to distinguish S. taiwanicus and S. bellulus . In general, the elytral punctures in S. bellulus are more distinct than those in S. taiwanicus , and often also the sides of frons and vertex in the former species bear a few distinct punctures, whereas the head in S. taiwanicus is virtually impunctate. However, in the sample of both species examined during the present study some problematic specimens were found, difficult to unambiguously identify by external features. The aedeagi of these species are similar ( Figs 15–21 vs. Fig. 22 ), but while there is a remarkable male genital variability within the studied populations of S. bellulus , the aedeagi of all studied specimens of S. taiwanicus are almost identical. The aedeagus of S. taiwanicus ( Fig. 22 ) is slenderer than that in S. bellulus , with the distal region in ventral view subequal in length and width to the basal capsular region, the apex is broadly rounded, and the ventral wall above the basal diaphragm forms a distinct elongate median impression flanked by longitudinal ridges visible in slide preparations as darkly sclerotized areas. A very similar, but stouter aedeagus was illustrated for S. donggonganus Wang & Li, 2016 that occurs in Zhejiang, East China, and it is possible that the latter taxon is only a continental subspecies of S. taiwanicus .

Figures

FIGURES 13–14. Dorsal habitus of male. Stenichnus bellulus Jałoszyński (from Yonaguni-jima) (13); Stenichnus taiwanicus Franz (14).

FIGURES 15–22. Stenichnus bellulus Jałoszyński (15–21); Stenichnus taiwanicus Franz (22). Aedeagus in ventral view; specimens from Iriomote-jima, Funauki (15), Iriomote-jima, Ôhara (16), Iriomote-jima, Ôtami-rindô (17), Taiwan, Fushan (18), Yonaguni-jima (19), Taiwan, Anmashan (20), Iriomote-jima, Komi (21).