Tyrodes Raffray, 1908

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

Genus Tyrodes Raffray, 1908

[Japanese common name: Nisekoke-arizukamushi Zoku]

Tyrodes Raffray, 1908: 379 . Type species: Tyrus histrio L. W. Schaufass, 1887 (subsequent designation by Lucas 1920: 663). Tyrodites Jeannel, 1960: 455 . Type species: Tyrodites championi Jeannel, 1960 (synonymized by Besuchet 1970: 316).

Diagnosis. Head with small, nude frontal median fovea and one pair of larger, setose vertexal foveae; maxillary palpi large, each with palpomeres 2–4 each pedunculate basally, widened apically; palpomeres 4 each with sensory appendage at apex; pronotum with antebasal sulcus connecting median and lateral foveae; abdomen with tergite IV longer than V; aedeagus stout, with ovoid median lobe ( Raffray 1908; Jeannel 1957; Yin & Li 2013).

Comments. The genus Tyrodes is similar to Tyrus Aubé, 1833 in their general appearances, but it is distinguished from the latter by the following characteristics: frontal median fovea small, nude (distinct, larger, setose in Tyrus ); abdominal tergite IV longer than V (IV and V subequal in Tyrus ) ( Yin & Li 2013). In addition, after an examination of previous studies and the specimens studied in this paper, the following characteristics may also be useful for separation of both genera: male antennomeres 1 each with triangular projection on the external side of the basal part ( Figs 1C , 5C ) (usually lacking the triangular projection in Tyrus , but T. sichuanicus Yin & Nomura, 2013 has laterally expanded antennomeres 1), and tergite IV lacking median longitudinal carina ( Fig. 3A ) (usually present in Tyrus , but lacking in T. myrmecophilus Bryant, 1915 ) ( Raffray 1908; Bryant 1915; Jeannel 1957; Besuchet 1970; Yin & Li 2013; Yin et al. 2013; Zhang & Yin 2023).

The genus Megatyrus Hlaváč & Nomura, 2003 share the characteristic of antennomeres 1 with Tyrodes , but the members of Megatyrus are easily separated from Tyrodes by the larger body, maxillary palpi with palpomeres 4 each lacking apical appendage, and tergite IV with well-defined median longitudinal carina ( Hlaváč & Nomura 2003).

Among the Japanese Tyrodes species, the male shares following characteristics: posterolateral clypeal region strongly concave with demarcate edge ( Fig. 2A, C, D ); metaventrite with small setose projection ( Figs 1E , 5D ); sternite IV–V strongly concave at lateral parts ( Figs 1F , 3B , 5E ).

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 5. Morphology of Tyrodes amamianus sp. nov., male. A. Dorsal habitus. B. Ventral habitus. C. Antennomere 1. D. Metaventral projection. E. Lateral side of abdomen. F. Tergite VIII. G. Sternite VIII. H. Sternite IX. Scale bars: 1.0 mm in A, B; 0.5 mm in E; 0.2 mm in D; 0.1 mm in C, F–H.