Pachyserica sanqingshanensis 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 : 48-50

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

Fig. 21A–E

Type material examined. Holotype ♂ “[ China] Jiangxi, Shangrao, Mt. Sanqingshan 2007.4.15 ~20, Lei Shi leg. / Ophthalmoserica sp. / En-002276 / PHOTO” ( SYSU).

Description of holotype. Length: 9.7 mm, length of elytra: 7.1 mm, width: 4.9 mm. Body oblong-oval and convex, including legs entirely reddish brown, each centre of elytron with a darker patch behind middle and before apex, antennae more yellowish, midline of pronotum, basomedial portions of scutellum and irregular markings on elytra dark green, dorsal surface dull, frons with dark toment, head and pronotum with yellow, erect long setae, entire body with dense, adpressed, white, scale-like setae, and elytra with sparse, larger but semierect ones.

Labroclypeus subrectangular, approximately 1.4 times wider than long, widest at middle, lateral margins weakly convex, in anterior half more strongly convergent; anterior angles broadly rounded; anterior margin very weakly emarginated; margins strongly reflexed; surface flat, dull, coarsely and densely punctate, with dense, long and erect setae; frontoclypeal suture distinct, finely incised and flat, weakly curved; smooth area anterior to eye as wide as long; ocular canthus moderately long and narrow (slightly longer than 1/3 of ocular diameter), with three moderately long setae in apical half. Frons flat, with large and dense punctures, adpressed scale-like setae dense beside eyes and, but sparser, on disc, additionally with dense, long and erect setae. Eyes large, ratio diameter/interocular width: 0.9. Antenna with ten antennomeres; antennomeres three to six almost as wide as long, antennomere seven transverse and very short, club with three antennomeres, 1.7 times as long as remaining antennomeres combined and convex. Mentum strongly elevated. Labrum strongly produced and distinctly emarginate medially, with two large, sharp teeth beside emargination.

Pronotum trapezoidal, distinctly wider than long, widest at base, lateral margins slightly concave in basal half and strongly convergent anteriorly, in anterior half slightly convex and strongly convergent anteriorly; anterior angles not produced, broadly rounded in tip; posterior angles almost right-angled, rounded at tip; anterior margin straight, with distinct and complete anterior marginal line; surface densely and finely punctate, midline impunctate at basal half, each puncture bearing a short, adpressed scale-like setae which are laterally denser and thicker; anterior and lateral margins with sparse, long and erect setae; hypomeron distinctly carinate, carina weakly produced ventrally. Scutellum wide and long, triangular, finely and densely punctate, with minute, adpressed scale-like setae, basomedial area impunctate and glabrous.

Elytra oval, widest at posterior quarter, striae indistinctly impressed, finely and moderately densely punctate, intervals weakly convex, with rather dense punctures, dark spots completely smooth and glabrous; intervals with dense, fine, short, white, adpressed setae, intervals additionally with fine, single, white, long, scale-like setae; epipleural edge fine, ending at moderately curved external apical angle of elytra, epipleura densely setose; apical border narrowly membranous, with a very fine membranous rim of fine microtrichomes (magnification 100x).

Ventral surface dull, finely and densely punctate, mesosternum with dense, long setae, hypomeron, metasternum and metacoxa with short, dense, adpressed scale-like setae, metasternal disc additionally with fine, long setae; metacoxa additionally laterally with few robust setae; abdominal sternites finely and moderately densely punctate, with a transverse, somewhat irregular row of large punctures, each bearing a short, robust seta, otherwise also covered with fine, adpressed, scale-like setae. Mesosternum between mesocoxae almost as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.44. Pygidium moderately convex, dull, midline widely impunctate, otherwise coarsely and densely punctate, with dense, short, adpressed scale-like setae in basal half, and with dense, erect long setae in apical half.

Legs slender; femora with two longitudinal rows of setae, finely and densely punctate; metafemur dull, anterior margin acute, without a continuously serrated line behind anterior margin; ventral posterior margin serrated in apical half and weakly 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: 1/4.4; dorsal margin sharply carinate, with two groups of spines, basal group shortly before middle, apical group at three quarters of metatibial length but only with punctures left, basally with a few single, robust setae; lateral face longitudinally concave, finely and densely punctate, with longitudinal wrinkles, with some minute, adpressed setae; ventral margin serrated, with three, almost equidistant, robust setae; medial face sparsely punctate and glabrous; apex interiorly near tarsal articulation concavely truncate, finely serrated. Tarsomeres ventrally with moderately dense, minute setae, protarsomeres dorsally smooth, meso- and metatarsomeres dorsally with superficial and longitudinal wrinkles, and a few minute setae; meso- and metatarsomeres with a strongly serrated ridge ventrally; metatarsomeres laterally carinate, glabrous ventrally; first metatarsomere slightly shorter than following two tarsomeres combined and distinctly longer than dorsal tibial spur. Protibia short, bidentate, external margin smooth; anterior claws symmetrical, basal tooth of inner claw normal.

Aedeagus: Fig. 21A–C . Habitus: Fig. 21D, E . Female unknown.

Diagnosis. Pachyserica sanqingshanensis new species seems most similar to P. squamifera (Frey, 1972) , P. wangzizhaoi new species, and P. tianxuani new species. Pachyserica sanqingshanensis new species differs from them by the robuster parameres and the laterally strongly narrowed anterior part of phallobase.

Etymology. The name of this new species (adjective in nominative case) is derived from its type locality, Mount Sanqingshan in Jiangxi ( China).

Figures

FIGURE 21. A–E: Pachyserica sanqingshanensis new species (holotype); F–K: P. zhanbaoxiangi new species (holotype); A, H: aedeagus, left side lateral view; C, K: aedeagus, right side lateral view; B, J: parameres, dorsal view; I: aedeagus, dorsal view; D, F: habitus, dorsal view; E, G: habitus, lateral view. Scale bar: 0.5 mm. Habitus images not to scale.