Microserica vinden Ahrens, Lukic

Ahrens, Dirk, Liu, Wangang, Lukic, Daniel & Bai, Ming, 2023, A taxonomic review of Microserica Brenske, 1894 from continental Asia (Coleoptera: Scarabaeidae: Melolonthinae: Sericini), Zootaxa 5241 (1), pp. 1-115 : 43-44

Microserica vinden Ahrens, Lukic & Liu, new species

Figs. 14I–L , 28

Type material examined. Holotype: Ô “N-Vietnam Cao Bang Pr. vic. Vin Den Nui pia Oac Nature res. 10.- 15.V.2014 N22°33.53’; E105°52.53’ 900-1300m, leg. A. Weigel / collection Naturkundemuseum Erfurt/1114 Sericini Asia spec.” ( NME) . Paratypes: 4 ÔÔ “N-Vietnam Cao Bang Pr. vic. Vin Den Nui pia Oac Nature res. 10.-15.V.2014 N22°33.53’; E105°52.53’ 900-1300m, leg. A. Weigel / collection Naturkundemuseum Erfurt / 1114 Sericini Asia spec.” ( NME, ZFMK) .

Description of holotype. Length: 6.9 mm, length of elytra: 5.5 mm, width: 4.1 mm. Body oblong-oval, body brown, antenna and elytral intervals yellowish brown, elytral striae, scutellum, frons, and pronotum darker, with strong greenish shine, dorsal surface dull but partly iridescent, except large single white, scale-like setae on odd intervals glabrous.

Labroclypeus wider than long, widest at base, lateral margins convex and strongly convergent to convex anterior angles; anterior margin weakly emarginate medially, margins weakly reflexed; lateral margins and ocular canthus produce a blunt angle; surface shiny, medially convex, finely and coarsely, densely punctate, with a few long, erect setae anteriorly in transversal row; frontoclypeal suture finely incised and curved. Frons dull, with dense, fine punctures, beside eyes with a few single short setae, otherwise glabrous. Smooth area in front of eyes 1.5 times as wide as long. Ocular canthus impunctate, narrow and moderately long (1/3 of ocular width), with a terminal seta. Eyes moderately large, ratio of diameter/interocular width: 0.65. Antenna with ten antennomeres; club composed of four antennomeres, strongly reflexed, 1.8 times as long as remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum moderately wide, widest shortly before base, lateral margins evenly convex and convergent to distinctly produced and sharp anterior angles, posterior angles strongly rounded. Anterior margin of pronotum convex, with fine and complete marginal line; basal marginal line absent; surface finely and densely punctate, with minute setae in punctures, anterior and lateral anterior margins sparsely setose. Hypomeron not visibly carinate. Scutellum triangular, finely and densely punctate, on basal midline impunctate.

Elytra rather elongate, widest at posterior third, striae distinctly and broadly impressed, finely and densely punctate, intervals strongly convex, dark, with fine and sparse punctures concentrated only along striae, with very minute setae in punctures, odd lateral intervals with large single white, scale-like setae; epipleural edge robust, ending at slightly rounded external apical angle of elytra, epipleura densely setose; apical border broadly membraneous, with a broad fringe of short microtrichomes (visible at ca 100x magnification).

Ventral surface dull, finely and densely punctate, metasternum covered with fine, short, or very minute setae; metacoxa glabrous, with numerous long, white, and robust setae laterally. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.57. Abdominal sternites finely punctate, with a transverse row of coarse punctures, each bearing a robust seta. Pygidium moderately convex and dull, with mixed finer and larger punctures, without smooth midline, with short and long setae.

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 present; setae of anterior and posterior row long, dense, and fine; ventral posterior margin weakly widened in apical half, smooth, dorsal posterior margin also smooth, with a few short setae basally. Metatibia moderately long and narrow, widest at middle, ratio width/length: 1/3.6; dorsal margin longitudinally convex, with two groups of spines, basal group at first third, apical one at three quarter of metatibial length, basally with no other robust setae; lateral face strongly longitudinally convex, densely and coarsely punctate, with short or long setae in punctures; ventral margin carinate and finely serrate, with three robust setae of which the apical one is more distant; medial face smooth, apex interiorly near tarsal articulation sharply truncate. Tarsomeres with fine, dense setae ventrally, neither laterally nor dorsally carinate, dorsally smooth; metatarsomeres glabrous ventrally, 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 more than twice as long as dorsal tibial spur. Protibia moderately long, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Fig. 14I–K . Habitus: Fig. 14L . Female unknown.

Diagnosis. Microserica vinden Ahrens, Lukic & Liu, new species is in external appearance and morphology of aedeagus similar to Microserica costisquamosa (Ahrens, Fabrizi & Liu, 2019) new combination The new species differs by the much longer left paramere.

Etymology. The species name is named after its type locality, Vin Den (noun in apposition).

Figures

FIGURE 14. A–D: Microserica multipunctata Ahrens, Lukic & Liu, new species (holotype); E–H: Mic. hieroglyphica Ahrens, Lukic & Liu, new species (holotype); I–L: Mic. vinden Ahrens, Lukic & Liu, new species (holotype). A, E, I: Aedeagus, left side lateral view; C, G, K: Aedeagus, right side lateral view; B, F, J: Parameres, dorsal view; D, H, L: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 28. Distribution of the Microserica avicula group.