Scaphisoma sekerkai Löbl, 2021

Löbl, Ivan & Hájek, Jiří, 2021, Scaphisomatini (Coleoptera: Staphylinidae: Scaphidiinae) from two biosphere reserves in eastern China, with descriptions of two new species, Acta Entomologica Musei Nationalis Pragae 61 (2), pp. 495-501 : 498

Scaphisoma sekerkai Löbl , sp. nov.

( Figs 2, 5–8 )

Type locality. China: Fujian Prov.,Wuyishan Mts.NNR,Guadun vill.env., 27°44.6′N, 117°38.1′E, 1335 m.

Type material. H OLOTYPE ♂: CHINA: FUJIAN Prov. 29.v.2018 Wuyishan Mts. NNR, Guadun vill. env., mixed forest with flowering Castanopsis , individually from vegetation, dead wood, fungi, 27°44.6′N, 117°38.1′E, 1335 m J.Hájek, D.Král, J.Růžička & L.Sekerka lgt. ( IZCAS).P ARATYPES: 1 ♀: with the same data as the holotype ( NMPC); 2 ♂♂ 2 ♀♀: CHINA: FUJIAN Prov. 23.v.–3.vi.2018 Wuyishan Mts.NNR:Sangang 27°45.0′N, 117°40.7′E, 720 m; mixed forest + bamboo; on vegetation Hájek, Král, Růžička & Sekerka lgt. ( MHNG, NMPC).

Description. Length 1.51–1.67 mm, width 0.95–1.05 mm. Head blackish. Pronotum entirely dark brown to blackish, or somewhat lighter to ochraceous along lateral margin. Hypomera ochraceous. Elytra reddish-brown, each slightly to strongly darkened along suture, with dark brown to blackish base, apices, and transverse band situated anterior to elytral midlength, latter reaching to or separated from sutural stria. Mesoventrite and metaventrite with anepisterna and epimera dark brown to blackish, ventrites light brown to yellowish, exposed abdominal tergites and appendages yellowish.

Length/width ratios of antennomeres as: III 14/9: IV 28/8: V 48/8: VI 43/8: VII 50/12: VIII 42/10: IX 58/12: X 50/12: XI 60/12.

Pronotum not microsculptured, with lateral margins nearly evenly rounded, lateral margin carinae exposed in dorsal view, lateral margin carinae finely and densely punctate, discal punctation fine and dense, most puncture intervals slightly larger to three times larger than puncture diameters, punctures well delimited, clearly visible at 15 times magnification. Exposed point of scutellum minute.

Elytra not microsculptured, with lateral margins rounded in basal third, oblique posteriad, apical margins rounded, lateral margin carinae exposed in dorsal view, lateral margin striae finely and densely punctate, inner apical angles not prominent, about on level with outer apical angles, marginal crenulation very fine, sutural striae shallow, not or hardly bent at bases, parallel in basal halves, converging posteriad, adsutural areas flat, each with single puncture row, basal striae absent, discal punctures fairly fine and dense, coarser than pronotal or adsutural punctures, not forming rows, puncture intervals mostly about two to three times as large as puncture diameters.

Exposed tergites with few very fine punctures.

Hypomera with longitudinally striate microsculpture, appearing impunctate. Mesepimeron about 5 times as long as wide and 2.0 to 2.5 times as long as interval to mesocoxa. Metaventrite with transversely striate microsculpture. Median part of metaventrite weakly convex, slightly impressed apically, lacking separate impressions near metacoxae, with punctation distinct, sharply delimited, sparse on centre, fairly dense on apical area. Lateral parts of metaventrite each with dense antecoxal puncture row, punctation very fine and sparse on remaining surface. Submesocoxal area 0.04 mm long, about fourth of shortest interval to metacoxa; submesocoxal line convex, densely punctate. Metanepisterna slightly convex, impressed along arcuate suture, narrowed anteriad. Abdomen with transversely striate microsculpture.Ventrite I with few distinct basomedian punctures, very finely punctate on prevailing surface, submetacoxal area 0.08 mm long, about half of interval to apical margin of ventrite. Following ventrites very finely and sparsely punctate.

Protibiae straight, mesotibiae and metatibiae weakly bent. Male characters. Protarsomeres I distinctly widened, II slightly widened, III hardly widened. Mesotarsomeres I weakly widened, II and III hardly widened.Apex of ventrite VI gradually narrowed to form about 0.05 mm long triangle. Aedeagus ( Figs 5–8 ) 0.67–0.70 mm long.

Differential diagnosis. Member of the Scaphisoma rouyeri group, as defined in L ÖBL (1981a) and subsequently extended to include species lacking parameral lobes (e.g., L ÖBL & OG AWA 2016). The species is characterized by the following features, in combination: the elytra are darkened at bases, on the transverse stripe posterior to midlength and at the apices, the elytral punctation is not arranged to form distinct striae, the sutural striae start near pronotal lobe, the submesocoxal areas are about as long as one fourth of the shortest interval between them and the metacoxae, the submetacoxal areas are twice as long as the submesocoxal areas and half as long as the shortest intervals between them and the apical margin of the ventrite I, the metaventrite has dense antecoxal puncture rows, the ventrite I is very finely punctate except for its basomedian area, the apical process of the median lobe is curved and tapering, the parameres are strongly expanded near bases and sinuate in dorsal view and lack mesal lobes, the internal sac is tubular, strigulate in proximal section, and bears rows of marginal denticles. This new species falls in the key to the Chinese Scaphisoma (L ÖBL 2019a) under the couplet 54, to S. delictum Löbl, 1981 . It may be readily distinguished from the latter by the elytral colour pattern, the elytra lacking coarse puncture rows, and the parameres lacking mesal lobes. The parameres of this new species are similar to those of S. ruzickai Löbl, 2019 . These two species differ notably in their elytral colour pattern and punctation (much finer in S. sekerkai sp. nov.), and the structures of the internal sac (with a median tuft of robust teeth in S. ruzickai , with long marginal rows of short denticles and a striate basal tube in S. sekerkai sp. nov.).

Collection circumstances. At the type locality, Scaphisoma sekerkai sp. nov. was collected on the border of tea plantation and mixed forest with flowering Castanopsis sp. ( Fig. 13 ); the precise collection circumstances are not known.

Etymology. Patronymic. The species is named in honour of one of its collectors, the well-known leaf beetle expert Lukáš Sekerka (NMPC).

Distribution. So far known only from two very close localities in the Wuyishan Mts. NNR, Fujian, China.

Figures

Figs 1–8. Scaphisoma Leach, 1815 from Wuyishan Mts. 1, 3–4 – Scaphisoma krali sp. nov.; 2, 5–8 – Scaphisoma sekerkai sp. nov. 1–2 – habitus in dorsal view; 3, 5 – aedeagus in dorsal view; 4, 8 – aedeagus in lateral view; 6 – basal bulb and internal sac in dorsal view; 7 – paramere in ventral view. Scale bars: Figs 1–2 = 1 mm; 3–8 = 0.1 mm.

Figs 9–13. Habitat of Scaphisoma Leach, 1815 in Wuyishan Mts. 9–10 – Xiaofeng Mountain; 11–13 – Guadun. 9 – general view of broad-leaved forest with bamboo; 10 – detail of sifted microhabitat; 11 – general view of short bamboo forest with intermixed high evergreen trees; 12 – detail of sifted bamboo bush; 13 – border of tea plantation and mixed forest with flowering Castanopsis sp.