Eutheia clepsydra, Jałoszyński, 2024

Jałoszyński, Paweł, 2024, Two new species of Eutheiini in Taiwan (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 5447 (4), pp. 591-599 : 592-594

Eutheia clepsydra sp. n.

( Figs 1 , 4–8 , 13 )

Type material. Holotype: TAIWAN: ♁, two labels: “TAIWAN, Kaohsiung / Hsien, Kuanshan, / Kuhanoshing Hut / 3020 m 18.IV.1992 / A. Smetana [ T92 ]” [white, printed]; “ EUTHEIA \ clepsydra m. \ det. P. Jałoszyński, 2024 \ HOLOTYPUS” [red, printed] ( MHNG) . Paratype: 1 ♁, “TAIWAN Nantou / Hsien, Houhuanshan / 3100m 20.IV.1990 / A. Smetana [ T12 ]”, and a yellow “PARATYPUS” label ( MHNG) .

Diagnosis. Male: body large (BL> 1.5 mm); head and pronotum with dense and sharply marked punctures, elytra with fine and diffuse punctures; antennae weakly thickening distally, with antennomeres 3–7 each about as long as broad and 8–10 each weakly transverse; aedeagus in ventral view with basal capsule and distal structures subequal in length, base of distal region much narrower than capsular region; distal region weakly broadened in its proximal half, with large membranous apical lobes separated by deep U-shaped emargination; in lateral view aedeagus with deeply inflexed ventral wall near middle.

Description. BL 1.58–1.83 mm. Body of male ( Fig. 1 ) flat and strongly elongate, dark brown with elytra slightly lighter than head and pronotum and with slightly lighter appendages, covered with light brown setae.

Head broadest at large and bean-shaped eyes, HL 0.20–0.23 mm, HW 0.30–0.35 mm; vertex and frons confluent and flattened. Punctures on frons small but distinct, sharply marked and dense, separated by spaces equal to and shorter than diameters of punctures; setae on frons and vertex sparse, short, suberect. Antennae slender and weakly gradually thickened, AnL 0.75–0.78 mm, antennomeres 1–2 distinctly elongate, 3–7 each about as long as broad, 8–10 weakly transverse, 11 distinctly shorter than 9 and 10 combined, about 1.8 × as long as broad.

Pronotum broadest near middle; PL 0.35–0.40 mm, PW 0.45–0.50 mm; anterior margin arcuate; lateral margins strongly and evenly rounded, so that pronotum is distinctly narrowing anteriorly and posteriorly; hind corners weakly obtuse-angled and with sharply defined apices; posterior margin shallowly bisinuate; pronotal base with five clearly-defined and relatively deep pits (outer lateral pits deepest, median pit shallow). Punctures on pronotal disc about as large and sharply marked as those on frons, separated by spaces subequal to diameters of punctures; setae short, sparse and suberect.

Elytra together oval, broadest near anterior third; EL 0.83–1.00 mm, EW 0.60–0.70 mm, EI 1.38–1.43. Punctures on elytra similarly dense and large as those on pronotum but much shallower and with diffuse margins; setae short, sparse and suberect. Hind wings well developed.

Pygidium with punctures finer than those on elytra.

Legs moderately long and slender, unmodified.

Aedeagus ( Figs 4–8 ) strongly elongate and complex; AeL 0.35 mm; in ventral view basal capsule of median lobe strongly elongate and equally long as distal region of aedeagus; distal region narrow at base and in subapical area and weakly broadened near its middle length; apex with large distolateral membranous lobes separated by deep U-shaped emargination. In lateral view, ventral wall of median lobe deeply inflexed near middle length of aedeagus. Parameres slender, each with two long and one short apical setae. Aedeagus showing some variability, paratype male ( Fig. 6 ) slightly differs from holotype in the shape of apical lobes.

Female. Not known.

Distribution. Northern and southern Taiwan ( Fig. 13 ).

Etymology. The noun in apposition clepsydra refers to the water clock shape of the aedeagus.

Remarks. Species of Eutheia are externally highly uniform and identification in most cases must be based on unique male genital structures. Among species occurring in Taiwan, Japan and the Russian Primorsky Krai, E. clepsydra , E. gramme Jałoszyński, 2008b , E. horii Jałoszyński, 2004 , E. klapperichi Franz, 1985 , E. latissima Jałoszyński, 2008b , E. rufa Jałoszyński, 2004 , E. simillima Franz, 1985 , E. taiwanensis Franz, 1985 and E. yoshidai Hoshina, 2007 share a bifurcate or at least deeply concave apical margin of the median lobe, whereas the geographically closest E. exortiva Kurbatov, 1990 and E. hariola Kurbatov, 1991 (Primorsky Krai) have the aedeagi with the apical margin convex or straight. Only in two species of this region— E. latissima and E. clepsydra —the median lobe in lateral view is similarly wide in the proximal capsular region and at base of the distal region, and these regions are demarcated by a deep and narrow inflection of the ventral wall. In other species, the distal region in lateral view already at its base is much narrower than the basal capsule. Eutheia latissima and E. clepsydra are also similar in a relatively broad body form and punctures on the head, pronotum and elytra. The main difference between these Taiwanese species is the shape of the distal region of the median lobe in ventral view. In E. latissima , the proximal portion of the distal region is strongly broadened, the broadening is as wide as the width of the capsular region, and near middle the distal region is abruptly and deeply constricted, so that at the narrowest point it is as wide as only half width of the basal capsule. In E. clepsydra , the widened area and the constriction are both much less distinct, and the broadest site is clearly narrower than the capsular region, whereas the subapical shallow constriction is much wider than half width of the basal capsule. Among Chinese species, only E. puetzi Jałoszyński, 2008a has the aedeagus in lateral view resembling that of E. latissima and E. clepsydra , i.e., with the deep inflection of the ventral wall separating the wide distal region from the proximal capsule. However, in ventral view, the aedeagus of E. puetzi has a tripartite apical region, with a strongly elongate median projection flanked by narrow and spatulate distolateral lobes.

Figures

FIGURE 13. Distribution of nominal Eutheia species in Taiwan, Japan and Russian Far East.

FIGURES 1–3. Eutheia clepsydra sp. n. (1), and Paraneseuthia spinipes sp. n. (2, 3). Dorsal habitus of males (1, 2); fore leg (3).

FIGURES 4–12. Eutheia clepsydra sp. n. (4–8), and Paraneseuthia spinipes sp. n. (9–12). Aedeagus of holotype (4–5, 7–12) and paratype (6) in ventral (4, 6, 7, 9, 11) and lateral (5, 8, 10, 12) views.