Euconnus (Tetramelus) mediorufus Jałoszyński, 2024, sp. nov.
Creators: name: Jałoszyński, Paweł
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Euconnus
Euconnus mediorufus

description: Euconnus (Tetramelus) mediorufus sp. nov.
(Figs 20, 29–30, 89–96)
Material studied. Holotype: ♂ (CHINA: Yunnan): “CHINA: N-Yunnan [C2005-05] / Diqing Tibet. Aut. Pref., / Zhongdian Co., Xue Shan near / lake 23 km S Zhongdian, 3895 m ”, “ 27°37.1’ N, 99°38.5 E, devast. / mixed forest, meadows, lake / border, leaf litter, dead wood, / sifted, 5.VI.2005, / leg. M. Schülke ” [white, printed], “ EUCONNUS / (TETRAMELUS) / mediorufus m. / P. Jałoszyński, 2024 / HOLOTYPUS” [red, printed] (MNHB). Paratype: ♂, “CHINA, Yunnan, / Haba Shan, N27°21’57’’ / E100°06’55’’, / 29.vi.2012, 3362m, / sift36 V. Grebennikov” [white, printed] (cPJ).
Diagnosis. Body rufous brown; male metatrochanter distally produced into long subtriangular spine, ventral margin of trochanter evenly concave in distal half; aedeagus in ventral view slightly less than twice as long as wide, its ventral plate much wider than long, with lateral margins strongly sinuate and strongly converging distally to narrow rounded apex, dorsal plate elongate, with sinuate lateral margins strongly converging to narrowly rounded apex, endophallus in ventral view with one short elongate sclerite surrounded by endophallic folds covered densely with cuticular denticles.
Description. Body of male (Fig. 20) elongate and slender, moderately convex, with long appendages, BL 1.98–2.13 mm; cuticle glossy, pigmentation rufous brown, vestiture of setae lighter than cuticle.
Head in dorsal view round, broadest across eyes, HL 0.33–0.35 mm, HW 0.33–0.35 mm; in lateral view each temple about 3.5 times as long as eye; vertex weakly convex and only slightly bulging posterodorsally; frons flattened; supraantennal tubercles small and indistinctly elevated. Eyes small, finely faceted, hardly projecting laterally from head silhouette, in lateral view oval. Punctures on vertex and frons inconspicuous, small and sparse; setae short and sparse, suberect, sparse and short thick bristles present on vertex and tempora. Antennae slender, indistinctly shorter than half BL, AnL 0.88–0.90 mm; antennomeres 1–5 elongate (3–5 indistinctly so), 6–8 each about as long as broad, 9 and 10 each weakly transverse, 11 slightly shorter than 9–10 combined, about 1.5 times as long as broad.
Pronotum broadest anterior to middle, PL 0.48–0.53 mm, PW 0.43–0.45 mm; anterior margin arcuate, lateral margins rounded in anterior half and nearly straight in posterior third, posterior corners slightly obtuse-angled, blunt; posterior margin weakly rounded. Pronotal base with single outer pair of small but distinct pits. Punctures on pronotal disc inconspicuous; setae moderately dense and short, suberect and on sides mixed with thick bristles.
Elytra oval, broadest slightly in front of middle, EL 1.18–1.25 mm, EW 0.80 mm, EI 1.47–1.56; basal impressions and humeral calli lacking, elytral apices rounded together. Punctures on elytral disc inconspicuous, superficial; setae similar to those on pronotum, moderately dense and weakly suberect.
Legs long and slender, metatrochanter (Figs 29, 30) distally produced into long subtriangular spine, ventral margin of trochanter evenly concave in distal half.
Metaventrite with deep oval median impression occupying most of its surface, extending on almost entire length.
Aedeagus (Figs 89–96) stout with slender apical region, AeL 0.55 mm; median lobe in ventral view broadest distally to middle or near middle, distally rapidly narrowing, ventral plate much wider than long, with lateral margins strongly sinuate and strongly converging distally to narrow rounded apex, dorsal plate elongate, with sinuate lateral margins strongly converging to narrowly rounded apex, endophallus in ventral view with one short elongate sclerite surrounded by endophallic folds covered densely with cuticular denticles. Dorsal wall with short setae; parameres slender, each with 3 long subapical setae.
Female. Not known.
Distribution. WS China: Yunnan, Diqing Tibetan Autonomous Prefecture.
Etymology. The adjective mediorufus refers to the medium body size and to the reddish-brown pigmentation.
Remarks. Males of Euconnus mediorufus have the metatrochanters modified similarly to those in E. punctator and E. magnirufus, with a relatively long subtriangular distal spine and the ventral margin arcuate, not bent. The three species share also a similar endophallic structure, with membranous folds densely covered with numerous cuticular denticles. The dorsal plate in E. mediorufus is conspicuously elongate and narrow, whereas in E. punctator it is elongate but broad, and in E. magnirufus the plate is nearly as long as broad.
The two studied males differ slightly in metatrochanters (Figs 29 and 30) and in aedeagi (Figs 89–92, and 93–96). However, these differences are too small to justify establishing two separate species.
description: Published as part of Jałoszyński, Paweł, 2024, Subgenera Cladoconnus Reitter and Tetramelus Motschulsky of Euconnus Thomson discovered in China (Coleoptera, Staphylinidae, Scydmaeninae), pp. 232-256 in Zootaxa 5514 (3) on pages 252-254, DOI: 10.11646/zootaxa.5514.3.2, http://zenodo.org/record/13849780