Siamitoides carinatus, Jałoszyński, 2020

Jałoszyński, Paweł, 2020, Siamitoides gen. n., a new Oriental ant-like stone beetle genus (Coleoptera Staphylinidae: Scydmaeninae), Zootaxa 4868 (2), pp. 257-266 : 264-265

publication ID	https://doi.org/ 10.11646/zootaxa.4868.2.5
publication LSID	lsid:zoobank.org:pub:B32CFC79-57D5-49D1-93C3-EE7A692DFFF5
DOI	https://doi.org/10.5281/zenodo.4417735
persistent identifier	https://treatment.plazi.org/id/D752EF5A-8E3A-7C34-FF04-F930FC1B5D58
treatment provided by	Plazi
scientific name	Siamitoides carinatus
status	sp. nov.

Treatment

Siamitoides carinatus View in CoL sp. n.

( Figs 1–13 View FIGURES 1–3 View FIGURES 4–7 View FIGURES 8–13 )

Type material. Holotype: INDONESIA (Aceh): ♂, two labels: “SUMATRA: Aceh # 27 / Mt Leuser N.P. / Ketambe , 1000 m / 28-29.XI.1989, Löbl / Agosti , Burckhardt ” [white, printed], “ SIAMITOIDES / carinatus m. / HOLOTYPUS, P. JAŁOSZYŃSKI, 2020” [red, printed] ( MHNG).

Diagnosis. As for genus; vide supra.

Description. Body of male ( Fig. 1 View FIGURES 1–3 ) strongly convex, uniformly dark brown, covered with setae distinctly lighter than cuticle; BL 1.68 mm.

Head ( Figs 2–6 View FIGURES 1–3 View FIGURES 4–7 ) broadest at eyes, HL 0.30 mm, HW 0.30 mm; tempora in dorsal view about as long as eyes; vertex flattened; each eye ( Fig. 3 View FIGURES 1–3 ) moderately large and moderately strongly convex, bean-shaped, with shallow posteromedian emargination. Punctures on vertex fine, inconspicuous; setae long, sparse and suberect, obscured by long and dense thick bristles distributed on sides of posterior half of frons and on vertex, especially dense on tempora. Antennae ( Fig. 1 View FIGURES 1–3 ) short in relation to body, AnL 0.63 mm, antennomeres 1 and 2 each distinctly elongate, 3–10 each transverse, 11 about as long as 9–10 combined, 1.6 × as long as broad; all antennomeres covered with long, suberect setae.

Pronotum ( Figs 1, 3–4 View FIGURES 1–3 View FIGURES 4–7 ) subconical, broadest at base; PL 0.45 mm, PW 0.45 mm. Anterior margin rounded, sides weakly rounded, near anterior third slightly sinuate; posterior corners nearly right-angled; posterior margin very indistinctly bisinuate (barely discernibly concave in front of each basal elytral fovea); sides of disc along lateral carinae strongly flattened, but flattened surface not reaching posterior pronotal margin. Punctures on pronotal disc fine, inconspicuous; setae sparse, long, suberect; thick bristles present only on anteromedian region of each hypomeron, not visible in dorsal view, but well visible in lateral view ( Fig. 3 View FIGURES 1–3 ).

Elytra ( Figs 1 View FIGURES 1–3 , 4 View FIGURES 4–7 ) together oval, broadest distinctly in front of middle; EL 0.93 mm, EW 0.73 mm, EI 1.28; humeral calli distinct, elongate, basal impressions shallow and indistinct; apices separately rounded. Punctures inconspicuous; setae similar to those on pronotum.

Legs ( Fig. 1 View FIGURES 1–3 ) moderately long and slender, unmodified.

Aedeagus ( Figs 10–13 View FIGURES 8–13 ) elongate, in ventral view with slightly asymmetrical basal half and nearly symmetrical apical structures; apex of median lobe with pair of oval elongate projections flanking small subtriangular median projection; parameral base developed as large collar surrounding basal foramen, parameres massive, in ventral view each with apical portion bent mesad, in lateral view apices recurved, apical and subapical setae lacking.

Female unknown.

Distribution. Northwest Sumatra.

Etymology. The adjective carinatus refers to the conspicuous lateral pronotal carinae.

Remarks. The new genus seems extremely rare; the single male here described was found among over 30,000 Oriental specimens of Scydmaeninae accumulated in several museums.