Stenichnus (Stenichnus) bicolor (Denny)

Jałoszyński, Paweł, 2023, New species and new records of Eastern Palaearctic Stenichnus Thomson (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 5318 (3), pp. 363-381 : 372-373

Stenichnus (Stenichnus) bicolor (Denny)

( Figs 23–27 )

Scydmaenus Bicolor Denny, 1825: 68 . Redescribed in Franz (1960): 329 (as S. exilis Erichson, 1837 ).

Material studied. JAPAN, Iwate Prefecture: 1 ♁, Kawai, Yoshibezawa , 1050 m, 12.08.1991, leg. A. Smetana ( MHNG) .

Distribution. Eurasia: Austria, Belgium, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Great Britain, Germany, Georgia, Hungary, Ireland, Italy, Japan (Honshu), Lithuania, Mongolia, Netherlands, Norway, Poland, Romania, European & Asian Russia (incl. Siberia and Far East), Slovakia, Spain, Sweden, Switzerland, Ukraine.

Remarks. This broadly distributed but not common European species is also known to occur in the Asian part of Russia, including Siberia and Primorsky Krai ( Kurbatov 1993). Here recorded for the first time from Japan, where a single male was found in the northern region of Honshu. This species shows the largest area of distribution of all Stenichnus , ranging from Spain in the west to Japan in the east and spanning over 10,000 kilometers.

The Japanese specimen, slightly incomplete ( Fig. 23 ), was compared with European males of S. bicolor and no differences were found. This small-bodied species (adults measure 1.2–1.4 mm) usually has the elytra slightly lighter than the head and pronotum (although nearly uniformly dark brown specimens can also be found), and it can be easily identified by its unique aedeagus ( Figs 24–27 ).

Figures

FIGURES 23–27. Stenichnus bicolor (Denny). Dorsal habitus of male from Iwate Prefecture (23); aedeagus in ventral (24, 26) and lateral (25, 27) views.