Pachyserica sunfengyii 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 : 38-39

Pachyserica sunfengyii Ahrens, Zhao, Pham & Liu , new species

Fig. 15F–J

Type material examined. Holotype ♂ “ CHINA: Guangxi, Guilin, Lingui, Anjiangping 1310 m 25.563435°N, 109.941005°E 2023.V.31–VI.4 Feng-Yi Sun leg.” ( SCAU).

Description of holotype. Length: 11.0 mm, length of elytra: 7.9 mm, width: 6.8 mm. Body oval and strongly convex, dark brown, dorsal face with strongly greenish, iridescent shine, elytra without dark spots, antenna yellow, dorsal and ventral surface with fine, partly patchily distributed, or dense, short, adpressed, yellow, scale-like setae, on head, pronotum and anterior elytra with a few long, fine, erect, yellow setae.

Labroclypeus rectangular, distinctly wider than long, widest at middle, lateral margins convex and convergent anteriorly and slightly also basally, anterior angles strongly convex; anterior margin straight; margins weakly reflexed; surface flat, moderately shiny, coarsely and sparsely punctate, with a few long, erect setae; frontoclypeal suture indistinct, not elevated, and weakly curved; smooth area anterior to eye 1.2 times as wide as long; ocular canthus long and narrow (1/3 of ocular diameter), impunctate and with two short setae at apex. Frons flat, with fine and dense punctures, with fine, partly dense, adpressed, lanceolate and long, erect setae beside eyes and on disc, setae on disc sparser. Eyes small, ratio diameter/interocular width: 0.53. Antenna with ten antennomeres; club with three antennomeres, 1.2 times as long as remaining antennomeres combined and straight. Mentum elevated and anteriorly flattened. Labrum moderately produced medially, shallowly emarginate medially, broadly rounded beside median emargination.

Pronotum trapezoidal, distinctly wider than long, widest at base, lateral margins moderately concave in basal half, strongly convergent anteriorly, at middle slightly convexly bent, and in anterior half weakly convex and strongly convergent anteriorly; anterior angles not produced, convex, almost obsolete; posterior angles acute; anterior margin straight, with a fine marginal line; surface moderately densely and finely punctate, with widely impunctate patches and midline, with partly dense, fine, short, adpressed, oblong setae and with a few long, erect setae; anterior and lateral margins with long, moderately dense setae; hypomeron distinctly carinate, carina produced ventrally. Scutellum slender and long, triangular, finely and densely punctate, with short, adpressed scale-like setae as in pronotum, median base widely impunctate and glabrous.

Elytra oval, widest at middle; striae distinctly impressed, finely and densely punctate, intervals convex, almost completely impunctate, some parts with fine, irregular, and sparse punctures; some patches on intervals with dense, fine, short, adpressed, lanceolate or oblong setae, intervals on apical declivity and lateral intervals with a few, fine, long, erect setae; epipleural edge robust, ending at moderately curved external apical angle of elytra, epipleura densely setose; apical border without a membranous rim of fine microtrichomes (magnification 100x).

Ventral surface dull, finely and densely punctate, base of hypomeron with dense, adpressed, lanceolate setae, metasternum and metacoxa with dense, small, adpressed, lanceolate setae, metasternal disc additionally with fine, long setae; metacoxa additionally laterally with few robust setae; abdominal sternites with a narrow, weakly elevated midline, surfaces finely and densely punctate, with a transverse row of coarse punctures, each bearing a short, robust seta, otherwise densely covered with fine, adpressed, oblong setae. Mesosternum between mesocoxae almost as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.77. Pygidium strongly convex, finely and densely punctate, with wide, smooth midline, with dense, oval, adpressed scales and sparse, fine, long, erect setae.

Legs moderately slender; femora with two longitudinal rows of setae, coarsely and densely punctate between rows; metafemur iridescent 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 moderately slender and long, widest shortly before apex, ratio of width/length: 1/3.9; dorsal margin sharply carinate, with two groups of spines, basal one at one third, apical one at two thirds of metatibial length, basally with a few single, robust setae; lateral face longitudinally concave, along finely and densely punctate, punctures elongate, without longitudinal wrinkles, with sparse, short, white, adpressed setae; ventral margin serrated, with three equidistant, robust setae; medial face sparsely punctate and glabrous; apex interiorly near tarsal articulation concavely truncate. Tarsomeres ventrally with sparse, minute setae, dorsally finely sparsely punctate; metatarsomeres laterally weakly carinate, with a strongly serrated ridge ventrally; first metatarsomere slightly shorter following two tarsomeres combined but distinctly longer than dorsal tibial spur. Protibia short, bidentate, external margin smooth; anterior claws symmetrical, apical tooth rather slender, basal tooth moderately widened.

Aedeagus: Fig. 15H–J . Habitus: Fig. 15F, G .

Diagnosis. Pachyserica sunfengyii new species is similar to both, P.striatipennis Moser, 1908 and P.hoabinhensis new species. Pachyserica sunfengyii new species differs from its siblings by its large, sub-triangular and apically blunt basal lobe of both parameres.

Etymology. This species (noun in genitive case singular) is named after the collector, Mr. Feng-Yi Sun (Yong’an, China).

Figures

FIGURE 15. A–E: Pachyerica yaonani new species (holotype); F–J: P. sunfengyii new species (holotype); A, H: aedeagus, left side lateral view; C, J: aedeagus, right side lateral view; B, I: parameres, dorsal view; D, F: habitus, dorsal view; E, G: habitus, lateral view. Scale bar: 0.5 mm. Habitus images not to scale.