Tyrodes segrex Kurbatov, 1990

Inoue, Shota & Nomura, Shûhei, 2023, New species and record of Tyrodes Raffray (Coleoptera: Staphylinidae: Pselaphinae) from Japan, Zootaxa 5375 (1), pp. 83-92 : 84-87

Tyrodes segrex Kurbatov, 1990

( Figs 1–3 , 4A–D )

[Japanese common name: Tsuyu-Nisekoke-arizukamushi]

Tyrodes segrex Kurbatov, 1990: 144

. Material examined (26♂♂, 20♀♀). Japan. [Hokkaidô]: 1♂, Kamikawa-gun, Shintoku-chô , Kuttari , near Tomuraushi-onsen , 21 VII 2011, Y. Hirano leg. ( NMNS) ; 1♀, same data as above, but 8–14 VI 2021 ( NMNS) ; 1♂, same data as above, but 18–23 IX 2013 ( NMNS) ; [Honshû: Aomori-ken]: 1♂, 14♀♀, Hirosaki-shi, Mt. Iwaki-san , Hyakuzawa trail (alt. 380 m) , 40.631°N, 140.324°E, 23 VI 2023, S. Inoue leg. (cSI); 3♂♂, Ajigasawamachi, Fukayamachi , Shirakami-no-mori (alt. 370 m) , 40.674°N, 140.190°E, 24 VI 2023, looking wood, S. Inoue leg. (cSI); [Fukushima-ken]: 3♂♂, Aizu, Okutadami, Mt. Asakusa-dake , 22 VII 1987, S. Nomura leg. ( NMNS) ; [Ibaraki-ken]: 1♂, Kitaibaraki-shi, Sadanami , 2,3–17,18 VII 2002, Malaise trap, H. Gotô leg. ( NMNS) ; [Tôkyô-to]: 2♀♀, Nishi-okutama-gun, Okutama-machi, Nippara, Mt. Ikkoku-yama-Mt. Ningyô-yama (alt. 1000–1200 m), 4 V 2007, H. Kamezawa leg. ( NMNS) ; [Ishikawa-ken]: 1♀, Hakusan-shi, Shiramine, Ichinose , 30 IV 2000, K. Nakata leg. ( NMNS) ; 1♂, Hakusan-shi, Mt. Ôarashi-yama (alt. 950 m), 11 VI–2 VII 2016, FIT, K. Nakata leg. ; 1♀, Hakusan-shi, Shiramine, Tengukabe (alt. 600 m), 5–15 VI 2022, air-FIT, K. Nakata leg.; [Gifu-ken]: 2♂♂ , 1♀, Gujô-shi, Hachiman-chô, Nabi , 18 IV 1986, K. Suzuki leg. ( NMNS) ; [Okayama-ken]: 1♀, Tomata-gun, Kagamino-chô, Kamisaibara (alt., 850 m), 27 IX 2010, Y. Fujitani leg. ( NMNS) ; [Hiroshima-ken]: 1♂, Yamagatagun, Kitahiroshima-chô, Mt. Garyû-san , 5 V 2015, N. Tsuji leg. (cSI): [Kyûshû: Ôita-ken]: 11♂♂, Yufu-shi , Shônaichô , Asono , Mt. Kurodake (alt., 1015 m), 17 VI 2021 , 33.122°N, 131.298°E, looking wood, S. Inoue leg. (cSI); 2♂♂, same data as above, but by bark stripping (cSI); 1♂ same data as above, but by spraying (cSI); [Miyazaki-ken]: 1♂, Miyakonojô-shi, Natsuo-chô, Mîke , 22 VI 2019, R. Ito leg. (cSI) .

Revised diagnosis. Dorsal habitus as in Fig. 1A, B . Body length 1.75–2.0 mm. Posterolateral clypeal region strongly concave in male ( Fig. 2A, C–D ), unmodified in female ( Fig. 2B ); antennomeres 1 each with triangular projection on lateral side in male ( Fig. 1C ), lacking projection in female; each male antennomeres 9–11 slightly larger than in female; meso-metaventrite covered with dense setae ( Fig. 1D ); metaventrite with small setose projection in male ( Fig. 1E ), lacking in female; male metafemora covered with slightly longer, denser setae than in other leg; abdominal tergite IV lacking discal carina ( Fig. 3A ); tergite VIII with small projection at middle in female ( Fig. 3D ); abdominal sternite IV with shallow concavity at posterolateral in male; sternite V with deep concavity in male ( Figs 1F , 3B ); sternite IV–V unmodified in female ( Fig. 3C ): sternite IV–VII shallowly impress at middle, with tufts of setae directed posteriorly in male, simple in female; aedeagus ( Fig. 6A–C ) with symmetrical median lobe; apex of median lobe truncated in lateral view; endophallus composed of two sclerites and one membrane.

Distribution. Japan (Hokkaido, Honshu, Kyushu); Primorski, Russian Far East.

In Japan, two prefectural records are already reported as Tyrodes sp. We checked the specimen used by the previous records, and we identified these as Tyrodes segrex . So, we revised the following records as Tyrodes segrex .

—Tôkyô-to: Tyrodes sp. ( Kamezawa & Nomura 2012).

—Gifu-ken: Tyrodes sp. ( Takai 2015; Nomura & Kamezawa 2016).

Biology. This species is collected from under bark and tree holes, similar to Tyrus species. Kurbatov (1990) reported that specimens of Tyrodes segrex were collected under moss on maple trees. The first author also collected many individuals from similar habitats in Aomori-ken, Japan ( Fig. 4A–C ). Furthermore, the first author found many walking males on the surfaces of trees in Aomori-ken and Ôita-ken in June ( Fig. 4D, E ). Female individuals are found under the moss. Only two individuals were collected with Lasius fuliginosus -group sp. ants (as proposed by Boudinot et al. 2022), but these individuals were possibly collected accidentally with the ants ( Kamezawa & Nomura 2012).

Comments. This species distributed in the wide range of mainland Japan from Hokkaido to Miyazaki-ken, Kyushu and no other Tyrodes species is found from the region. So the Japanese undescribed species mentioned in Besuchet (1970) maybe this species. But we have not checked the specimen.

Figures

FIGURE 1. Morphology of Tyrodes segrex Kurbatov (A, C–F. Male. B. Female). A, B. Dorsal habitus. C. Antennomere 1. D. Meso- and metaventrite and ventral side of abdomen. E. Metaventral projection. F. Lateral side of abdomen. Scale bars: 1.0 mm in A, B; 0.5 mm in D, F; 0.2 mm in E; 0.1 mm in C.

FIGURE 2. Head of Tyrodes segrex Kurbatov (A, C–D. Male. B. Female) in SEM images. A, B. Head in lateral view; C. Posterolateral clypeal region in lateral view; D. Posterolateral clypeal region in dorsal view. Abbreviations: ant1—antennomere 1; mp—maxillary palpus.

FIGURE 3. Morphological details of Tyrodes segrex Kurbatov (A–B. Male. C–D. Female) in SEM images. A. Tergite IV. B, C. Abdomen in lateral view. D. Tergite VIII—enlarged image of the dashed white line square in Fig. 2C.

FIGURE 4. Collecting environment and habitat of Tyrodes segrex (A–C. Mt. Iwaki-san, Aomori-ken; D, E. Mt. Kurodake, Ôitaken). A, D. Collecting site. B, C. The moss where T. segrex inhabited. D. The tree T. segrex were walking on.

FIGURE 6. Aedeagus of Tyrodes segrex Kurbatov (A–C) and Tyrodes amamianus sp. nov. (D–F). A, D. Ventral view. B, E. Lateral view. C, F. Dorsal view. Scale bar: 0.1 mm in A–F.