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

description: Euconnus (Tetramelus) tetraspinosus sp. nov.
(Figs 16, 24–25, 73–76)
Material studied. Holotype: ♂ (CHINA: Gansu): “CHINA: Gansu Prov. [CH11-12] / Lenglong Ling Mts., pass road 61.5 km / N Honggu, 2875-2900 m, 36°53’11.0’’N, / 102°45’30.8’’E, dry grass steppe and / field edges,
under stones, running on / trail, 29. VI.2011, leg. M. Schülke ” [white, printed], “ EUCONNUS / (TETRAMELUS) / tetraspinosus m. / P. Jałoszyński, 2024 / HOLOTYPUS ” [red, printed] (MNHB).
Diagnosis. Body dark brown; male with peculiar modifications of pro- and metatrochanters: protrochanter with conspicuously long and straight distal process broadening distally and truncate at apex, metatrochanter with long and strongly curved distal process broadening distally and truncate at apex; aedeagus in ventral view nearly four times as long as wide, its ventral plate elongate, with lateral margins weakly converging distally to broadly rounded apex, dorsal plate strongly elongate, with weakly sinuate lateral margins strongly converging distally to narrow rounded apex, endophallus in ventral view with three elongate sclerites, of which lateral ones are conspicuously long, and median sclerite is much shorter, all sclerites surrounded by membranous folds densely covered with cuticular denticles.
Description. Body of male (Fig. 16) elongate and slender, moderately convex, with long appendages, BL 1.95 mm; cuticle glossy, pigmentation dark brown with indistinctly lighter appendages, vestiture of setae lighter than cuticle.
Head in dorsal view round, broadest across eyes, HL 0.33 mm, HW 0.35 mm; in lateral view each temple 3 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 mm; antennomeres 1–6 elongate (6 weakly so), 7–8 each about as long as broad, 9 and 10 each weakly transverse, 11 slightly shorter than 9–10 combined, about 1.7 times as long as broad.
Pronotum broadest anterior to middle, PL 0.50 mm, PW 0.40 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 and shallow 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 anterior to middle, EL 1.13 mm, EW 0.73 mm, EI 1.55; basal impressions and humeral calli lacking, elytral apices separately rounded. Punctures on elytral disc inconspicuous, superficial; setae similar to those on pronotum, moderately dense and weakly suberect.
Legs long and slender, protrochanter (Fig. 24) with conspicuously long and straight distal process broadening distally and truncate at apex, ventral margin of protrochanter bent at a nearly right angle, metatrochanter (Fig. 25) with long and strongly curved distal process broadening distally and truncate at apex, ventral margin of metatrochanter proximally straight and distally strongly curved.
Metaventrite with deep oval median impression occupying most of its surface, extending on almost entire length.
Aedeagus (Figs 73–76) conspicuously elongate, AeL 0.85 mm; median lobe in ventral view broadest near middle, in distal third rapidly narrowing distally, ventral plate elongate, with lateral margins weakly converging distally to broadly rounded apex, dorsal plate strongly elongate, with weakly sinuate lateral margins strongly converging distally to narrow rounded apex, endophallus in ventral view with three elongate sclerites, of which lateral ones are conspicuously long, and median sclerite is much shorter, all sclerites are surrounded by membranous folds densely covered with cuticular denticles. Dorsal wall lacking setae; parameres slender, each with 3 long subapical setae.
Female. Not known.
Distribution. Central China: Central Gansu.
Etymology. The adjective tetraspinosus refers to the spines present on the pro- and metatrochanters.
Remarks. This species is the easiest to identify of all Chinese Tetramelus. No other species of world Euconnus has so uniquely modified pro- and metatrochanters in males, and among the Chinese species E. tetraspinosus has a remarkably elongate aedeagus, much more slender than any other Tetramelus found in this country.
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 246-248, DOI: 10.11646/zootaxa.5514.3.2, http://zenodo.org/record/13849780