Serica (Serica) xizang Ahrens, Zhao, Pham & Liu, 2024

Ahrens, Dirk, Zhao, Ming-Zhi, Pham, Phu Van & Liu, Wan-Gang, 2024, Taxonomic updates on Pachyserica Brenske, 1898 and Serica MacLeay, 1819 reveal 38 new species and new challenges of Sericini systematics regarding DNA barcodes and genus-level diagnostic key characters (Coleoptera: Scarabaeidae: Sericinae), Zootaxa 5491 (1), pp. 1-89 : 18-19

Serica (Serica) xizang Ahrens, Zhao, Pham & Liu , new species

Fig. 6A–F

Type material examined. Holotype ♂ [ China] “LW-1353 / Xizang Linzhi Bayi town, 2011-VII-31 / Asia Sericini 1331 spec.” ( ZFMK) . Paratypes: 6 ♂♂ [ China] “Hanmi Motuo Coun. Xizang A.R. alt. 2200m 14-VIII-2005 Tang Liang leg.” ( SNUC) .

Description of holotype. Length: 7.2 mm, length of elytra: 5.3 mm, width: 4.0 mm. Body oblong, brown, head darker, antenna yellow, legs reddish brown, punctures on elytra lighter, dorsal surface dull; elytra with sparse, moderately long, adpressed white setae, otherwise glabrous.

Labroclypeus as wide as long, widest at base, lateral margin convex and moderately convergent anteriorly, anterior angles weakly rounded, anterior margin distinctly emarginate medially, margins strongly reflexed; surface flat, shiny, finely and densely punctate, with superficial transverse wrinkles and a few long, erect setae behind anterior margin; frontoclypeal suture indistinct, finely incised and weakly curved; smooth area anterior to eye moderately large and strongly convex, about 1.7 times as wide as long; ocular canthus short and sharply triangular (1/8 of ocular diameter), smooth, with short terminal seta. Frons flat, entirely shiny; surface with fine and irregular and dense punctures, with a two long, erect setae beside eyes, otherwise glabrous. Eyes large, ratio diameter/ interocular width: 0.92. Antenna with ten antennomeres; antennomeres six and seven transverse and short; club with three antennomeres, 2.2 times as long as remaining antennomeres combined and strongly reflexed. Mentum anteriorly convexly elevated. Labrum transverse, short, moderately produced, moderately emarginate medially.

Pronotum moderately narrow, widest at base, lateral margins in basal half concave and weakly convergent towards middle, in anterior half strongly convex and convergent anteriorly, anterior angles weakly produced and rounded, posterior angles blunt, rounded at tip; anterior margin medially convex and with a complete, distinct marginal line; surface moderately densely and finely punctate, with minute setae in punctures, otherwise glabrous; anterior and lateral margins with moderately long and sparse setae; hypomeron distinctly carinate at base. Scutellum slender and long, dull, triangular, finely and densely punctate.

Elytra oblong, widest at apical third, striae weakly impressed, finely and densely punctate, intervals flat, with fine, moderately dense punctures, dark spots completely smooth; odd intervals with sparse, fine, short, adpressed, white setae; epipleural edge fine, ending at moderately curved external apical angle of elytra, epipleura densely setose, apical border chitinous, without membranous rim of fine microtrichomes (magnification 100x).

Ventral surface dull, finely and not densely punctate, moderately densely setose, metacoxa glabrous, with a few long setae only laterally; abdominal sternites finely and densely punctate, with a transverse row of coarse punctures, each bearing a short seta. Mesosternum between mesocoxae half as wide as the slender mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.49. Pygidium moderately convex and dull, finely and densely punctate, smooth midline lacking, with a few moderately dense and long setae.

Legs slender; femora with two longitudinal rows of setae, coarsely and not densely punctate between the rows, with robust setae on basal half; metafemur shiny, anterior margin acute, without a continuously serrated line behind anterior margin, ventral posterior margin serrated in apical half and not widened, dorsal posterior margin completely serrated, in basal half with a few long setae which are half as long as width of metafemur. Metatibia slender and long, widest at apex, ratio of width/length: 1/4.6; dorsal margin sharply carinate, with two groups of spines, basal group at basal third, apical group at two thirds of metatibial length, basally with a few single, robust setae; lateral face longitudinally concave, impunctate but superficially wrinkled; ventral margin serrated, with two very widely separated short but robust setae; medial face with a shallow longitudinal groove medially, sparsely punctate and glabrous; apex interiorly near tarsal articulation distinctly but bluntly truncate. Tarsomeres ventrally with sparse, minute setae, dorsally impunctate and without wrinkles; metatarsomeres laterally and dorsally carinate, with a strongly serrated ridge ventrally, ventrally glabrous; first metatarsomere distinctly shorter than following two tarsomeres combined and less than twice as long as dorsal tibial spur. Protibia moderately long, bidentate, external margin with a few small teeth in base half; protarsomeres missing in the holotype.

Aedeagus: Fig. 6A–D . Habitus: Fig. 6E–F . Female unknown.

Diagnosis. Serica xizang new species is similar to Serica zianii Sreedevi, Speer, Fabrizi & Ahrens, 2018 and S. olivacea Brenske, 1896 . The new species differs from S. olivacea Brenske, 1896 by the narrower and apically narrowed right paramere; the left paramere is only half as long as the right one. Furthermore, the pronotum of the new species at base wider than at middle, while in S. olivacea the middle is slightly wider than the base. Compared to S. zianii , Serica xizang new species the right paramere is less strongly narrowed behind the basal quarter, and the left paramere is less curved (both in dorsal view).

Etymology. The name of this new species (noun in apposition) is derived from its occurrence in Xizang ( China).

Variation. Length: 7.2–7.5 mm, length of elytra: 5.3–5.4 mm, width: 4.0– 4.1 mm.

Figures

FIGURE 6. A–F: Serica xizang new species (holotype); G–L: S. jiangda new species (holotype); A, I: aedeagus, left side lateral view; D, L: aedeagus, right side lateral view; C, K: parameres, dorsal view; B, J: aedeagus, dorsal view; E, G: habitus, dorsal view; F, H: habitus, lateral view. Scale bar: 0.5 mm. Habitus images not to scale.