Stenomastigus mpumalanganus Jałoszyński, 2025, sp. nov.
Creators: name: Jałoszyński, Paweł
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Stenomastigus
Stenomastigus mpumalanganus

description: Stenomastigus mpumalanganus sp. nov.
(Figs 1–6, 13–15)
Type material. Holotype: ♂, two labels: “ RSA, Mpumalanga 20.xi.2023 / 25°2.7’S 30°50.95’E, / Klipkraal, ind. forest / 1210m, P. Bulirsch lgt.” [white, printed], " STENOMASTIGUS / mpumalanganus m. / P. JAŁOSZYŃSKI, 2024 / HOLOTYPUS” [red, printed] (TMSA). Paratypes (5 exx.): 2 ♂♂, 3 ♀♀, same data as for the holotype, all with yellow “PARATYPUS” label (cPB, cPJ).
Diagnosis. Head, maxillary palps and femora dark brown, nearly black, pronotum dark umbra brown, elytra light umbra brown, antennae and distal regions of legs light to dark brown. Male (Fig. 1): protrochanter unmodified (Fig. 14); protibia with shallow subapical emargination (Fig. 13); antennae ~1.2–1.3 times as long as body; aedeagus (Figs 3–6) in abparameral view with conspicuously small and elongate basal capsule, much narrower than parameral region, ‘collar’ surrounding orifice projecting laterally beyond basal capsule, constriction separating basal capsule and parameral region distinct, paramere curved and with apex placed in long axis of aedeagus, in lateral view paramere weakly curved and directed towards abparameral side of median lobe. Female (Fig. 2): antennae ~1.1 times as long as body; elytra broadest near anterior third; each elytron with deep sub-basal impression, elytral suture in posterior 2/3 distinctly raised, elytral apex in dorsal view sharp-angled, in lateral view (Fig. 15) posterior elytral margin sinuate and oblique in relation to coronal body plane.
Description. Body of male (Fig. 1) elongate and slender, with extremely long appendages, BL 3.55–3.73 mm; pigmentation of head, maxillary palps and proximal regions of legs dark brown, nearly black, pronotum dark umbra brown, elytra light umbra brown, antennae and distal regions of legs (from tibiae) variously light to dark brown; vestiture whitish.
Head broadest at eyes, HL 0.68–0.70 mm, HW 0.65–0.70 mm; tempora in dorsal view nearly twice as long as eyes and distinctly converging posterad; median longitudinal impression of frontovertexal region distinct but diffuse; head dorsum densely covered with microscopic punctures, spaces between punctures glossy; setae extremely short, dense and recumbent. Antennae 1.23–1.34 times as long as body, AeL 4.45–4.75 mm; scape and pedicel strongly enlarged, each with five pairs of long ventral setae arranged in two longitudinal rows, all flagellomeres strongly elongate, indistinctly broadening distad.
Pronotum pear-shaped in dorsal view, elongate and broadest near anterior third, PL 0.93–1.00 mm, PW 0.68– 0.78 mm; anterior margin weakly arcuate; lateral margins strongly rounded in anterior half, strongly sinuate in posterior third; posterior margin nearly straight; pronotal disc with indistinctly marked, weakly elevated median longitudinal carina not reaching posterior margin. Surface finely microsculptured and matte, with dense, very short and recumbent vestiture.
Elytra together regularly oval, broadest near middle, EL 1.88–2.03 mm, EW 1.25–1.35 mm, EI 1.50–1.54; elytral apices separately rounded; surface covered with similar microsculpture and vestiture as pronotum.
Legs conspicuously long and slender; protrochanters unmodified (Figs 13, 14); protibiae with shallow subapical emargination (Fig. 13).
Aedeagus (Figs 3–6) conspicuously slender, AeL 1.68 mm, in abparameral view basal capsule strikingly small, elongate, much narrower than parameral region and delimited by distinct constriction; ‘collar’ surrounding orifice strongly projecting laterad beyond lateral margins of basal capsule; paramere slightly shorter than copulatory piece, curved mesad, with apex aligned with long axis of aedeagus. In lateral view, aedeagus broadest in sub-basal region, paramere weakly curved towards abparameral side of median lobe, with apical region straight.
Female (Fig. 2). Similar to male in body pigmentation, microsculpture and vestiture, differs clearly in shape of elytra and unmodified protibiae. BL 4.35–4.50 mm; HL 0.75 mm, HW 0.73–0.75 mm, AnL 4.75–4.93 mm (1.09 times as long as BL); PL 1.10–1.13 mm, PW 0.78–0.80 mm; EL 2.50–2.63 mm, EW 1.55–1.68 mm, EI 1.57–1.61. Elytra broadest near anterior third and strongly narrowing posterad, sub-basal dorsal impression on each elytron deep, suture raised roof-like from anterior third to apex, apices forming sharp angle, in some specimens short posterior adsutural region split, in others left and right elytron in dorsal view touching each other up to apex; in lateral view (Fig. 15) elytron strongly broadening posterad, with highest point situated near posterior third, posterior margin sinuate and oblique in relation to coronal body plane.
Distribution. EN region of Republic of South Africa, Mpumalanga.
Etymology. The epithet mpumalanganus refers to the province where the type series has been collected.
Remarks. The aedeagus of S. mpumalanganus resembles that of S. franzi Leleup, 1968 and S. pseudofranzi Jałoszyński, 2012b. They all share a relatively small basal capsule distinctly delimited by a deep constriction. Males and females of S. franzi, however, are uniformly black (illustrated in Jałoszyński (2012b)), and the paramere in lateral view is strongly curved (weakly so in S. mpumalanganus), in abparameral view distinctly longer than that in S. mpumalanganus. Moreover, the ‘collar’ surrounding the orifice in S. franzi is not projecting laterad beyond the basal capsule, so that in abparameral view it is not visible. The female elytron in lateral view strongly differs, in S. mpumalanganus the highest point is near the posterior third and the distal margin is sinuate (Fig. 15), while in S. franzi the elytron is not broadening behind middle and its distal margin is not sinuate (Fig. 19). The aedeagus of S. pseudofranzi is similar to that of S. mpumalanganus, and also the body pigmentation is similarly light (illustrated in Jałoszyński (2012b)). However, the basal capsule is slightly broader than the parameral region (much narrower in S. mpumalanganus), and the paramere is longer in relation to the remaining region of the aedeagus. Also, the lateral shape of the female elytron in S. mpumalanganus is clearly different from that in S. pseudofranzi (Fig. 15 vs. Fig. 20). The aedeagus of S. mpumalanganus, especially in abparameral view, resembles also copulatory organs of S. berlinafricanus Jałoszyński, 2012a and S. kosianus Jałoszyński, 2012a. Males of these species have strongly modified protrochanters, produced into a long distal projection, while the protrochanter in S. mpumalanganus is unmodified, and the body pigmentation in S. berlinafricanus and S. kosianus is uniformly dark brown.
description: Published as part of Jałoszyński, Paweł, 2025, Two new species of the South African genus Stenomastigus Leleup (Coleoptera, Staphylinidae, Scydmaeninae), pp. 101-112 in Zootaxa 5590 (1) on pages 102-105, DOI: 10.11646/zootaxa.5590.1.5, http://zenodo.org/record/14952788