Tachinus (Tachinus) bidens Sharp, 1888

Hashizume, Takuto, Schülke, Michael & Maruyama, Munetoshi, 2024, Tachinus of Japan (Coleoptera: Staphylinidae: Tachyporinae): new records, a new synonym, and a new species, Acta Entomologica Musei Nationalis Pragae 64 (1), pp. 121-139 : 127-128

Tachinus (Tachinus) bidens Sharp, 1888

[Japanese name: Kataaka-marukubi-hanekakushi]

( Fig. 1H )

Tachinus bidens Sharp, 1888:380 (original description); ULLRICH (1975):

169 (synonymized with T. sibiricus ; designation of a lectotype); LI

(1995a): 62 (as a junior synonym of T. sibiricus ; redescription);

SCHȖLKE (2015): 8 (as valid species).

Type material studied. LECTOTYPE: ♁, “♁ Tachinus bidens Type D.S. Sap. Japan Lewis [at mounting card] / Syntype [round, pale blue margin] / Type [round, red margin] / Japan G. Lewis / Sharp Coll.1905-313 / Tachinus sibiricus Shp. # W.G.Ullrich det.19318 / Lectotypus Tachinus bidens Shp. # des. W.G. Ullrich 1974 19318 [red]” ( BMNH) . PARALECTOTYPES: 1 ♁, “ Tachinus bidens D.S. Nikko Japan 25.8.81 Lewis [at mounting card] / Syntype [round, pale blue margin] / Japan G. Lewis 1910-320 / Paralectotypus Tachinus bidens Shp. ♁ des. W.G. Ullrich 1974 20942 [red] / Tachinus sibiricus Shp. ♁ W.G. Ullrich det. 20942” ( BMNH); 1 ♀, “ ♀ Japan 25.8.81 Lewis [at mounting card] / Syntype [round, pale blue margin] / Japan G. Lewis 1910-320 / Paralectotypus Tachinus bidens Shp. ♀ des. W.G. Ullrich 1974 19319 [red] / Tachinus sibiricus Shp. ♀ W.G. Ullrich det. 19319” ( BMNH).

Additional material examined. JAPAN: HOKKAIDO: 10 ♁♁ 22 ♀♀, Nopporo, 12.vi.1987, M.Ôhara leg.( KUM); 1 ♁, same data, but 14.vi.1986 ( KUM); 6 ♁♁ 5 ♀♀, same data,but 16.v.1987 ( KUM); 1 ♁, same data, but 15.ix.1988 ( KUM); 1 ex., Sapporo env., Nopporo Virgin Forest, 15.v.2010, T. Lackner leg. (cSch); 1 ex., Nopporo Forest Park, 24.v.–5.vi.2008, T. Lackner leg. (cSch); 2 ♀♀, Toro-ko, Shibecha-chô, 25.vi.1989, K. Haga leg. ( KUM); 1 ♁ 1 ♀, Ashoro-chô, 30.vii.1988, K. Haga leg.( KUM); 1 ♁, Ashoro-chô, 13.vi.1984, O.Tadauchi leg.( KUM);1 ♁ 1 ♀, Menashidomari (about 400 m alt.), Esashi-chô, 17.vii.2019, K. Haga leg. ( KUM); 1 ex., Otaamoi Kaigan,Otaru env., 7.viii.2008,T.Lackner leg.(cSch). RISHIRI- TṎ IS.: 1 ♁, 28.vi.1975, S. Imasaka leg. ( KUM). HONSHU: AOMORI- KEN: 2 ♁♁ 3 ♀♀, Rangan-no-mori, 26–31.vii.2003, Y. Kawahara leg. ( KUM). IWATE- KEN: 4 ♁♁ 6 ♀♀, Kawara-bo,Hayachine-san,Hanamaki-shi, 22–24. vi.1980, S. Naomi leg.( KUM). FUKUSHIMA- KEN: 1 ♁ 3 ♀♀, Kurosawahara–Korobushi-tôge, Minamiaizu-machi, 12.vi.1993, K. Haga leg.( KUM). TOCHIGI- KEN: 1 ♀, Tashiroyama-rindô, Kuriyama-mura, Nikkô-shi, 9.vii.1978, Ogasawara leg. ( KUM); 1 ♀, Yumoto, Nikkô-shi, 29.vi.1982, S. Naomi leg. ( KUM). GUNMA- KEN: 1 ex., 4 km NW Onioshadashi Rock Garden, 21.vii.1980, I. Löbl leg. ( MHNG); 4 exs., Nikko distr., Kozawa, 1000 m, 15.viii.1980, P.M. Hammond leg. ( BMNH). NIIGATA- KEN: 2 ♁♁, the confluence of Kiyotsu-gawa and Yagio-sawa–Yagio-sawa (1000 m alt.), 23.vi.1996, K. Haga leg. ( KUM). YAMANASHI- KEN: 1 ex., Hocchoudaira, Hokuto-shi, 22–26.vii.2001, T. Ueno leg. (cSch). TOKYO- TO: 1 ex., Mt. Tahao [Takao-san], 1.vi.1952, Yoshida Wada leg. ( NHMW). NARA- KEN: 1 ex., Shakagetakeyama, east side (1600 m alt.), 2.viii.2002, BOLM leg. ( SMNS). TOTTORI- KEN: 1 ♁ 1 ♀, Dai-sen, 3–5.vi.1980, S. Naomi leg. ( KUM). SHIKOKU: EHIME- KEN: 9 exs., Ichizuchi National Park, Tsuchigoya (1400 m alt.), 11–18.viii.1980, beech-fir forest, S. & J. Peck leg. ( FMNH, cSch); 17 exs., Ichizuchi National Park, Omogo valley (700 m alt.), 18–25.viii.1980, warm temperated forest, traps with dung, mushrooms at mossy trunk, S. & J. Peck leg. ( FMNH, cSch). KYUSHU: FUKUOKA- KEN: 1 ♀, Hiko-san, 25–30.vii.1969, M. T. Chûjô leg. ( KUM); 1 ♀, Naka-dake, Hiko-san, 13.x.1992, S. Nomura leg. ( KUM). OITA- KEN: 1 ♁ 1 ♀, Kuro-dake, Kuju, 19.vii.1992, S. Ogata leg. ( KUM). UNCLEAR LOCATION: 2 ♀♀, Sobo-san, 14.vii.1976, M. Ôishi leg. ( KUM) [Oita-ken/ Miyazaki-ken].

Diagnosis. Tachinus (Tachinus) bidens can be distinguished from other members of the subgenus Tachinus from Japan by the combination of the following characters: pronotum with distinct posterior angles; male sternite VII with a pair of large spoon-like setae at inner sides of lateral processes; female tergite VIII with four lobes. For detailed redescription, see LI (1995a: 62).

Distribution. Japan (Hokkaido incl. Rishiri-tô Is., Rebun- -tô Is., Honshu, Shikoku, Kyushu), Sakhalin, Kuril Isls. This species is widely distributed in lowland and montane zones in mainland Japan.

Remarks. Tachinus bidens Sharp, 1888 , and T. sibiricus Sharp, 1888 are very closely related. Both species differ only in slight but constant differences in body size, coloration, elytral length, and the shape and size of the field with modified setae on male sternite VII, the shape of the aedeagal apex in lateral view, and the shape of the lobes at the posterior margin of female tergite VIII. Since both species co-occur at least in southern Sakhalin, and no transitional specimens were found, a specific status of T. bidens can be assumed.

Figures

Fig. 1. Habitus of Tachinus spp.A – T. punctiventris Sharp, 1888; B – T. diminutus Sharp, 1888; C – T. iriomoensis Li, 1994; D – T. kobensis Cameron, 1933; E – T. naomii Li, 1994; F – T. nigriceps nigriceps Sharp, 1888; G – T. yamato (Hayashi, 2003); H – T. bidens Sharp, 1888; I – T. bipustulatus (Fabricius, 1792); J – T. elongatus Gyllenhal, 1810; K – T. gelidus Eppelsheim, 1893; L – T. japonicus Sharp, 1888. Scale bars = 1.0 mm.