Scaphidium grande Gestro, 1879

Löbl, Ivan, 2025, On the identity of Scaphidium grande, with resurrection of S. inimpressum and S. melanopus and description of two new species (Coleoptera: Staphylinidae: Scaphidiinae), Acta Entomologica Musei Nationalis Pragae 65 (1), pp. 15-20 : 16-17

Scaphidium grande Gestro, 1879

( Figs 1 , 6 )

Scaphidium grande Gestro, 1879: 50 .

Scaphidium grande var. subannulatum Pic, 1915:3 ; confirmed synonymy. Scaphidiolum grande : ACHARD (1924: 91).

Type material. Scaphidium grande . HOLOTYPE: J, labelled: ʻScaphidium grande. Gestro (typus! Sarawak) [handwritten] / Museo Civico di Genova [printed] / HOLOTYPUS [printed] J Scaphidium grande Gestro, 1879 [red label, handwritten] / grande Gestro [handwritten] / Typus [printed, red type] / Borneo Sarawak 1886-66 Coll. G. Doria [handwritten]ʼ ( MCSN). Scaphidium grande var. subannulatum . SYNTYPE: ♀, labelled: ʻPONTIANAK Borneo Holl.[printed] / S. grande var.subannulatum Pic [handwritten] / Muséum Paris 1958 coll. M. Pic [printed] / SYNTYPE [red label, printed] / Syntype Scaphidium grande var. subannulatum Pic, 1915 [printed] / MNHN Paris EC 41322 [printed]ʼ ( MHNH).

Additional material examined. MALAYSIA: SARAWAK: Kapit, Rumah Tuan Village, Balah River, 3.–5.iii.1994, leg. J. Horák, 3 JJ 3 ♀♀ ( MHNG); Quop [Kampung Kuap], 4.iv.1914, leg. G.E. Bryant, 1 J ( NMPC); Sebong, Balah River, 9.–12.iii.1994, leg. S. Bilý, 1 ♀ ( MHNG);

ca. 25 km E Kapit, iii.1994, leg.J. Kodada, 1J ( MHNG); Belaga District, Belaga Airport, 17.iii.1987, leg. M.Hiermeier, 1J ( MHNG); Matang,leg. J. Xantus, 1 J ( MHNG). INDONESIA: KALIMANTAN: Pelawan Bessar [Sangkulirang Distr.], M.E. Walsh, 1937, 3 JJ ( MNHN); Batan Bessi [near Sangkulirang], M.E. Walsh, 1937, 1 J ( MNHN); Pontianak, 1898, 1900 and 1901, 4 JJ ( MNHN).

Redescription. Body length 6.60–7.40 mm, width 4.90– 5.30 mm. Body black, with brown or reddish abdominal apex. Antennae with antennomeres I to VI dark brown to blackish, antennomeres II to VI with lighter apices, antennomeres VII to XI black. Femora black with reddish fascia on mesofemur and metafemur. Tibiae black. Tarsi brown or rufous. Frons flat, at narrowest point 0.35–0.39 mm wide, usually impunctate on small posterior area, punctation on prevailing surface not confluent, punctures on anterior area dense and partially elongate, on posterior area not elongate and sparse. Eyes large, eye width in dorsal view about 1.7 to 2.2 times as frons at narrowest point. Vertex distinctly punctate, with strigulate microsculpture. Punctation on clypeus finer and sparser than that on anterior part of frons. Pronotum raising above elytra, with lateral contours weakly sinuate, antebasal puncture row impressed, disc densely punctate, punctures round, smaller than puncture intervals; anterior margin straight in dorsal view, anterior margin stria with uninterrupted punctures row. Elytron with low humeral hump, disc in middle nearly horizontal, moderately inflexed and not impressed apicad; punctation posterior of humeral humps, on most of lateral areas and near apex slightly coarser than on pronotum, on most of inner discal surface finer than on pronotum; one or two discal rows of slightly larger punctures rather inconspicuous, sometimes hardly distinct; subbasal stria gradually impressed laterad, with coarse puncture similar to or larger than punctures of pronotal antebasal row; sutural stria finely punctate, adsutural area entirely raised and roof-like, or flattened near base. Prosternum with strigulate microsculpture, anterior and anterolateral margins of prosternum with coarse, almost confluent, not elongate punctures. Hypomeron smooth. Mesanepisternum and lateral parts of metaventrite extremely finely and very sparsely punctate, lacking microsculpture or with hardly visible strigulate microsculpture (magnification 100×) apicolateral areas of metaventrite. Mesanepisternum with anterior bead evenly narrow, delimited by stria nearly reaching posterior margin. Metaventrite impressed on apicomedian area. Ventrites with densely reticulate microsculpture. Ventrite I distinctly punctate on basomedian area, with few distinct punctures scattered on lateral areas. Ventrites II to IV with elongate basal striae evanescent on median areas, very finely and sparsely punctate.

Male. Profemur with ventral side flattened and bearing two or three irregular rows of tubercles. Protibia shorter than mesotibia, usually about as long as profemur, weakly curved, slightly, gradually thickened apicad, near apex about 1.2 times as broad as at base, with inner side bearing rows of tubercles; inner side of apex with short elongate ridge. Metaventral setal patch covering nearly entire mesal area of metaventrite, setae light brown, semierect, long. Aedeagus ( Figs 1 , 6 ) 2.23–2.56 mm (in holotype 2.42 mm) long.

Distribution. Borneo: Sarawak and Kalimantan (revised data).

Remarks. Scaphidium grande has a unique shape of aedeagus. The median lobe is abruptly narrowing at the level of the bases of the dorsal valves, and the lateral margins of the valves are parallel. The median lobe is gradually narrowing apicad from the level of the bases of the dorsal valves, and the lateral margins of the valves are converging in all species described by TANG & LI (2010) and TANG et al. (2016), in the Chinese specimens illustrated and identified as S. grande by TANG & LI (2010) and TANG et al. (2014) and in examined specimens from Nepal, Myanmar, Thailand, Vietnam, and China.

ACHARD (1924) assigned S. grande to Scaphidiolum Achard, 1922 , a name placed in synonymy of Scaphidium by LESCHEN & LÖBL (1995). The three varieties of S. grande, var. subannulatum , var. inimpressum , and var. melanopus , have been listed as invalid synonyms ( LÖBL 1992, 2018). The synonymy of only one of them, subannulatum, is here confirmed (it has the reddish fasciae of the femora darker and narrower than usually), while the other two are resurrected as valid species.

Figures

Figs 1–5. Aedeagi in Scaphidium grande group. 1 – S. grande Gestro, 1879 (Rumah Tuan Village, Sarawak); 2 – S. inimpressum Pic, 1920 (Defulan Trail, Taiwan); 3 – S. melanopus Achard, 1924 (lectotype); 4 – S. metafasciatum sp. nov. (holotype); 5 – S. grandior sp. nov. (holotype). Scale = 0.5 mm.

Figs 6–11. Internal sac of median lobe in Scaphidium grande group. 6 – S. grande Gestro, 1879 (Rumah Tuan Village, Sarawak); 7 – S. inimpressum Pic, 1920 (Defulan Trail, Taiwan); 8 – S. melanopus Achard, 1924 (lectotype); 9 – S. metafasciatum sp. nov. (holotype); 10 – S. grandior sp. nov. (holotype); 11 – Scaphidium sp. (Huisun, Taiwan).