Oxyserica nigropicta Ahrens & Liu & Lukic & Bai 2023, new combination

Oxyserica nigropicta (Fairmaire, 1891) new combination

Figs. 22A–D, 32

Serica nigropicta Fairmaire, 1891: 197.

Microserica nigropicta: Brenske 1897: 417, 1902: 47; Ahrens 2006: 239, 2007: 25; Ahrens & Bedzěk 2016: 298.

Type material examined. Lectotype (here designated): Ô “Chang Yang near Ichang 4-6000 ft. V,VII,VIII / nigropicta Fairm. Cotype [handwriting. Fairm.]” (MNHN). Paralectotype: 1 ♀ “Chang Yang / Museum Paris 1906 Coll. Leon Faimaire / Serica nigropicta F.” (MNHN).

Additional material examined. 1 ex. “ Chang Yang, near Ichang 4-6000 ft. V.VII.VIII. / Museum Paris Yang- Tse-Kiang Chang-Yang Brenske 1898 / S. nigropicta Typ. Comp.Fairm.Brenske det. 1898”(MNHN), 2 ex. “ Museum Paris Kouy-Tchéou Gan Chouen Fou, Kiang-Long et Tun-Lin-Tchéou, P. Cavalerie 1912” (MNHN), 2 ÔÔ, 2 ♀♀ “ Chang Yang near Ichang 6-8000 ft. June 88. / Coll. Kraatz / Moser det.” (DEIC), 5 ex. “ Museum Paris KouyTchéou Reg. de Pin-Fa, Père Cavalerie 1908” (MNHN), 2 ex. “Museum Paris Kouy-Tchéou, P. Cavalerie 1910” (MNHN), 2 ex. “ Museum Paris Kouy-Tchéou Gan Chouen Min y Fou et Loyang, P. Cavalerie 1912” (MNHN), 1 ex. “ Museum Paris Kouy-Tchéou, Kouy-Yang, P.P. Cavalerie et Fortunat 1906” (MNHN), 1 ex. “ Yunnan-Sen Mt. Excoffier 1898” (MNHN), 2 ex. “ Chine Yunnan Recu de Lou-Nan ” (MNHN).

Redescription. Length: 5.0 mm, length of elytra: 3.4 mm, width: 3.1 mm. Body oval, black, legs brown, elytra reddish brown with margins and one transversal mesolateral and one anteromedial spot black, dorsal surface dull and nearly glabrous.

Labroclypeus transversal, wider than long, shiny, widest at base, lateral margins in basal half almost straight, anteriorly strongly convex and convergent to rounded anterior angles; anterior margin weakly emarginate medially, margins weakly reflexed; lateral margins and ocular canthus produce a blunt angle; surface almost flat, coarsely and densely punctate, with numerous long, erect setae; frontoclypeal suture finely incised and curved medially. Frons dull, anterior quarter not covered with tomentum and shiny, with dense, fine punctures, beside eyes and behind frontoclypeal suture with numerous long setae, otherwise with minute setae in punctures. Smooth area in front of eyes convex, as wide as long. Ocular canthus finely densely punctate, wide and moderately long (1/3 of ocular diameter), with two terminal setae. Eyes very small, ratio of diameter/interocular width: 0.38. Antenna with ten antennomeres; club composed of four antennomeres, straight, 1.5 times as long as than remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum moderately wide, widest at base, lateral margins in basal half subparallel, anteriorly convex and convergent towards sharp and produced anterior angles; posterior angles blunt. Anterior margin of pronotum moderately convex, with fine but medially widely interrupted marginal line; basal marginal line absent; surface finely and densely punctate, glabrous, with minute setae in punctures; setae of lateral and anterior margins dense, extending on the disc around anterior angles. Hypomeron carinate, weakly produced ventrally. Scutellum triangular, finely and densely punctate, on base along middle narrowly impunctate.

Elytra elongate, widest at posterior third, striae weakly impressed, finely and densely punctate; sutural interval and lateral 2–3 intervals black, with a continuous black dot at anterior quarter from interval 2 to 4, and on posterior elytra between interval 4 to 7; intervals weakly convex, with fine and sparse punctures, with minute setae in punctures, penultimate lateral interval with a few short setae; epipleural edge fine, ending at rounded external apical angle of elytra, epipleura sparsely setose; apical border narrowly membranous, with a fine rim of short microtrichomes (magnification 100x).

Ventral surface dull, finely and densely punctate, metasternum sparsely covered with fine, short, or very minute setae; metacoxa glabrous, with a few single setae laterally. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.6. Abdominal sternites finely punctate, with a transverse row of coarse punctures, each bearing a robust seta. Pygidium weakly convex and dull, with dense, coarse punctures but without smooth midline, in punctures with numerous minute setae, with a few longer setae along apical margin.

Legs moderately wide; femora finely and sparsely punctate, with two longitudinal rows of longer setae. Metafemur moderately shiny, anterior margin acute, without submarginal serrated line; anterior row of seta-bearing punctures present; posterior margin smooth ventrally, widened in apical half, posterior margin smooth dorsally, with a few short setae basally. Metatibia moderately long and wide, widest at middle, ratio of width/length: 1/2.84; dorsal margin sharply carinate, with two groups of spines, basal group at anterior third, apical one at two thirds of metatibial length, in basal third without further robust setae; lateral face longitudinally convex, finely and sparsely punctate, with minute setae in punctures; ventral edge finely serrate, with three robust equidistant setae; medial face smooth, apex interiorly near tarsal articulation shallowly concavely truncate. Tarsomeres with fine, sparse setae ventrally, neither laterally nor dorsally carinate, dorsally smooth; metatarsomeres glabrous, with a strongly serrated ridge ventrally and a parallel subventral smooth carina immediately beside it; first metatarsomere little shorter than following two tarsomeres combined, little longer than dorsal tibial spur. Protibia short, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Fig. 22A–C. Habitus: 22D.