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

description: Stenomastigus bulirschi sp. nov.
(Figs 7–12, 16–18)
Type material. Holotype: ♂, two labels: “ RSA, Mpumalanga 22.xi.2023 / 24°54.7’S 30°51.1’E, Pinnacle / Rock, creek bank+swamp / ca 1450m, P. Bulirsch lgt.” [white, printed], “ STENOMASTIGUS / bulirschi m. / P. JAŁOSZYŃSKI, 2024 / HOLOTYPUS” [red, printed] (TMSA). Paratypes (7 exx.): 2 ♂♂, 5 ♀♀, same data as for the holotype, all with yellow “PARATYPUS” label (cPB, cPJ).
Diagnosis. Head, maxillary palps, antennae, pronotum and legs except tarsi nearly black, elytra dark umbra brown, tarsi brown. Male (Fig. 7): protrochanter modified, with distoventral region slightly projecting and with sinuate distal margin (Fig. 17); protibia with shallow subapical emargination (Fig. 16); antennae ~1.1–1.25 times as long as body; aedeagus (Figs 9–12) in abparameral view with conspicuously short but broad basal capsule, as wide as parameral region, ‘collar’ surrounding orifice not projecting laterally beyond basal capsule, constriction separating basal capsule and parameral region deep, paramere curved and with apex placed outside long axis of aedeagus, in lateral view paramere weakly curved and directed distally. Female (Fig. 8): antennae about as long as body; elytra broadest near anterior third; each elytron with deep sub-basal impression, elytral suture in posterior 1/6 distinctly raised, elytral apex in dorsal view truncate, in lateral view (Fig. 118) posterior elytral margin straight and transverse in relation to coronal body plane.
Description. Body of male (Fig. 7) elongate and slender, with long appendages, BL 3.18–3.64 mm; pigmentation of head, maxillary palps, antennae, pronotum and legs except tarsi nearly black, elytra dark umbra brown, tarsi brown; vestiture whitish.
Head broadest at eyes, HL 0.60–0.70 mm, HW 0.63–0.70 mm; tempora in dorsal view 1.5 times as long as eyes and distinctly converging posterad; median longitudinal impression of frontovertexal region distinct but diffuse; head dorsum densely covered with microscopic punctures, matte; setae extremely short, dense and recumbent. Antennae 1.10–1.24 times as long as body, AnL 3.93–4.03 mm; scape and pedicel strongly enlarged, scape with five, pedicel with four 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 between middle and anterior third, PL 0.83–0.98 mm, PW 0.68–0.73 mm; anterior margin weakly arcuate; lateral margins strongly rounded in anterior half, strongly sinuate in posterior third; posterior margin indistinctly arcuate; pronotal disc with barely discernible 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 1.75–2.00 mm, EW 1.25–1.30 mm, EI 1.40–1.54; elytral apices separately rounded; surface covered with similar microsculpture and vestiture as pronotum.
Legs long and slender; protrochanters modified, with distoventral region slightly projecting and with sinuate distal margin (Figs 16, 17); protibiae with shallow subapical emargination (Fig. 16).
Aedeagus (Figs 9–12) slender, AeL 1.55 mm, in abparameral view basal capsule strikingly short but broad, as wide as parameral region and delimited by deep constriction; ‘collar’ surrounding orifice not projecting laterad beyond lateral margins of basal capsule; paramere about as long as copulatory piece, curved mesad, with apex placed outside long axis of aedeagus. In lateral view, aedeagus broadest in sub-basal region, paramere weakly curved with abparameral margin convex.
Female (Fig. 8). Similar to male in body pigmentation, microsculpture and vestiture, differs clearly in shape of elytra and unmodified protrochanters and protibiae. BL 3.75–4.10 mm; HL 0.70–0.75 mm, HW 0.70–0.75 mm, AnL 3.95–4.15 mm (0.99–1.05 times as long as BL); PL 1.03–1.10 mm, PW 0.75–0.80 mm; EL 2.03–2.25 mm, EW 1.50–1.75 mm, EI 1.29–1.41. Elytra broadest near anterior third and moderately strongly narrowing posterad, sub-basal dorsal impression on each elytron deep, suture raised roof-like only near apex, apices subtruncate, in dorsal view posterior elytral margins forming posteriorly concave oblique angle; in lateral view (Fig. 18) elytron strongly broadening from base to middle and then parallel-sided, posterior margin nearly straight and transverse in relation to coronal body plane.
Distribution. EN region of Republic of South Africa, Mpumalanga.
Etymology. This species is dedicated to Petr Bulirsch, who collected the type specimens.
Remarks. The aedeagus of S. bulirschi resembles that of S. franzi and S. pseudofranzi. Males and females of S. franzi are uniformly black, and the paramere is much longer than the copulatory piece; in lateral view the abparameral margin of the paramere is straight (convex in S. bulirschi). The female elytron in lateral view strongly differs, in S. bulirschi the posterior margin is truncate (Fig. 18), while in S. franzi it is subtriangular (Fig. 19). The aedeagus of S. pseudofranzi is similar to that of S. bulirschi, but the body pigmentation is different—the pronotum and elytra in S. pseudofranzi are reddish-brown, whereas in S. bulirschi the pronotum is black, and the elytra brown. Moreover, the basal capsule of the aedeagus in S. pseudofranzi is distinctly more elongate, and the paramere is longer in relation to the remaining region of the aedeagus. The lateral shape of the female elytron in S. bulirschi is also clearly different from that in S. pseudofranzi (Fig. 18 vs. Fig. 20). The aedeagus of S. bulirschi, especially in abparameral view, resembles also copulatory organs of S. berlinafricanus and S. kosianus. Males of these species have protrochanters with much longer distal projections than that in S. bulirschi. Moreover, the body pigmentation in S. berlinafricanus and S. kosianus is uniformly dark brown. The aedeagus of S. bulirschi also resembles that of S. varii riparius Leleup, 1968, especially in abparameral view. In the former species the widest site of the aedeagus is submedian, whereas in the latter it is situated more distally, at the level of the endophallus. In lateral view, aedeagi of these species strongly differ in the general shape. Moreover, the pronotum in S. bulirschi is black, strongly contrasting with much lighter elytra, whereas in S. varii riparius the pronotum and elytra are dark reddish brown. Additionally, the lateral profile of the female elytron is different. In S. bulirschi, the posterior half of the elytron is parallel-sided, whereas in S. varii riparius there is a clearly marked highest site situated near middle length, and posteriorly the elytron is narrowing.
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 106-109, DOI: 10.11646/zootaxa.5590.1.5, http://zenodo.org/record/14952788