Euconnus (Euconnus) pubescens
Creators: name: Jałoszyński, Paweł
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Euconnus
Euconnus pubescens

description: Euconnus (Euconnus) pubescens (Nietner)
(Figs 30, 55–56)
Scydmaenus pubescens Nietner, 1856: 550.
Euconnus (Euconnus) pubescens (Nietner); Csiki, 1919: 50.
Euconnus nocturnilankanus Jałoszyński, 2011: 66, as new name for Euconnus nocturnus Franz, 1982: 249. Syn. nov. Euconnus nocturnus Franz, 1982: 249. Preoccupied, not Euconnus nocturnus Franz, 1958: 9.
Type material. Lectotype (here designated): ♂, three labels: “ Ceylon / Nietner..s” (white, printed and handwritten, text in black frame], QR code label with collection number 8187, and newly added “ EUCONNUS / (s. str.) / pubescens (Nietner, 1856) / LECTOTYPUS / P. Jałoszyński, 2025 ” (MIZ). Paralectotype: ♀, with white printed copy of locality label and identification labels with “PARALECTOTYPE” (MIZ).
Revised diagnosis. Vertex weakly bulging posterodorsad and with dense bristles; eyes large, in lateral view slightly shorter than tempora; antennal clubs tetramerous and longer than remaining flagellomeres combined; pronotum widest slightly anterior to base, and strongly narrowing anterad, with two lateral pairs of pits and with additional shallow and small median pit; aedeagus in ventral view with deeply bifurcate apex and with large symmetrical endophallus with two basilateral sclerites forming together a U-shaped structure flanking darkly sclerotized median complex.
Redescription. Body of male (Fig. 30) slender, strongly convex, moderately dark brown; setae distinctly lighter than cuticle; BL 1.18 mm.
Head broadest across eyes, HL 0.20 mm, HW 0.21 mm; frontal and anterior vertexal regions confluent, weakly convex, vertexal region weakly bulging posterodorsad; supraantennal tubercles barely marked; eyes large, in lateral view slightly shorter than tempora. Punctures on frons and vertex fine and inconspicuous; setae sparse, short and weakly suberect; tempora and vertex with dense and long bristles directed posteriorly. Antennae slender, with sharply delimited tetramerous clubs, AnL 0.50 mm; antennomere 1–2 each strongly elongate, 3–6 each about as long as broad, 7 indistinctly elongate, 8–10 each weakly transverse, 11 as wide as 10, much shorter than 9–10 combined, about 1.3 times as long as broad.
Pronotum subtrapezoidal, broadest slightly in front of base; PL 0.33 mm, PW 0.30 mm; anterior margin weakly arcuate, anterior corners poorly marked, obtuse-angled and blunt; lateral margins only slightly rounded; posterior corners nearly right-angled and blunt; posterior margin weakly arcuate; base with two pairs of small lateral pits, outer pair barely discernible, and with shallow and barely discernible median pit. Punctures on pronotal disc similar to those on frons and vertex, inconspicuous; setae moderately long, moderately dense and suberect, lateral margins with bristles.
Elytra together oval, broadest slightly anterior to middle; EL 0.65 mm, EW 0.45 mm, EI 1.44; humeral calli distinctly elevated, basal impressions shallow but distinct; elytral apices separately rounded. Punctures and setae similar to those on median region of pronotal disc.
Legs moderately long, slender, unmodified.
Aedeagus (Figs 55–56) was slightly damaged during preparation due to fragile condition of specimen (base is slightly distorted and parameres are missing); median lobe moderately elongate; AeL 0.18 mm; in ventral view oval with deeply bifurcate apex; endophallus large and symmetrical with two basilateral sclerites forming together a Ushaped structure flanking darkly sclerotized median complex, the latter composed of darkly sclerotized proximal element at middle and larger and less darkly sclerotized subapical structure.
Female. Unknown.
Distribution. Sri Lanka, near Colombo.
Remarks. The original description, although unusually short as for Nietner, agrees with the morphology of the single male. The number of type specimens was not specified, and the only available male must be treated as a syntype; it is here designated as the lectotype of Scydmaenus pubescens Nietner. Franz (1982) does not mention this name, but the aedeagus of his Euconnus nocturnus Franz, 1982 (nec E. nocturnus Franz 1958) is identical with that of the lectotype of S. pubescens. The preoccupied name Euconnus nocturnus Franz, 1982 was replaced by Euconnus nocturnilankanus Jałoszyński, 2011, which is here placed as a junior synonym of Euconnus pubescens Nietner.
Euconnus nocturnus was placed by Franz (1982) in the E. campanipenis species group, outside any subgenus. However, after listing diagnostic characters of this group, Franz stated that other representatives of this group are common in SE Asia and have been described by him in older works as belonging to the subgenus Napochus (literary translation). In fact, E. pubescens = nocturnus = nocturnilankanus externally strongly resembles the type species of Napochus, it is only slenderer, which is not a great difference. Its aedeagus, however, has a deeply bifurcate apex. Species showing a more elongate habitus, with the pronotum widest not at but in front of base, but also strongly narrowing anteriorly, and with the aedeagus with a bifurcate apex where at that time mainly placed in the subgenus Euconophron Reitter, 1909, which, alike Napochus, is now merged with Euconnus s. str. (Jałoszyński 2021b, 2022b). Vít (2005) argued that the bifurcate median lobe is an important diagnostic character of Euconophron, but later studies that lead to merging of this subgenus with Euconnus s. str. demonstrated that there are intermediate forms between the previously recognized subgenera. That Franz (1982) did not place the E. campanipenis group in Euconophron or Napochus is one of many examples how unclear the subgeneric diagnoses were.
External characters of E. pubescens are unremarkable and in tropical and subtropical regions all over the world very similar species can be found. The aedeagus, however, seems to be unique and allows for identification of this species.
description: Published as part of Jałoszyński, Paweł, 2025, John Nietner collection of Sri Lankan Scydmaeninae (Coleoptera, Staphylinidae), pp. 79-109 in Zootaxa 5633 (1) on pages 101-102, DOI: 10.11646/zootaxa.5633.1.4, http://zenodo.org/record/15372835