Pachyserica motuo 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 : 40-41

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

Fig. 16F–K

Type material examined. Holotype ♂ [ China] “on the way Beibeng to Motuo, Motuo , Xizang, 13. VIII.2003, 800– 1100m, leg. Ren Guodong / LW-262” ( HBUM) . Paratypes: 1 ♀ [ China] “along 108k, Motuo , Xizang, 17.VIII.2003, leg. Ren Guodong ” ( HBUM) , 1 ♂ “ CHINA: TIBET, Nyingchi City, Beibeng Township, Gelin Vill. , 1753 m, 29.214870°N, 95.169272°E, 18–30.VII.2023 (at light), Yao-Nan Zhang leg. / Se-XZ-7” ( SCAU) , 1 ♂ “ CHINA: TIBET, Nyingchi City, Beibeng Township, Gelin Vill. , 1753 m, 29.214870°N, 95.169272°E, 18–30.VII.2023 (at light), Yao-Nan Zhang leg.” ( CZMZ) , 1 ♂ “ CHINA: TIBET, Nyingchi City, Beibeng Township, Gelin Vill. , 1560 m, 2023.VIII.21 (at light), Zhi-Hao Qi, Jun Liu & Cheng-Xu Peng” ( CZMZ) .

Description of holotype. Length: 11.2 mm, length of elytra: 8.4 mm, width: 7.0 mm. Body oval and strongly convex, dark brown, dorsal face with greenish shine, elytra slightly lighter, with dark spots, antenna yellow, dorsal surface with weak iridescent shine, with fine, partly patchily distributed, or dense, short, adpressed, white, or yellowish setae, on head, pronotum and anterior elytra with long fine erect, yellow setae.

Labroclypeus rectangular, wider than long, widest at base, lateral margins in basal half straight and subparallel, anteriorly convex and convergent anteriorly, anterior angles strongly convex; anterior margin straight; margins weakly reflexed; surface flat, shiny, finely and sparsely punctate, with a few long, erect setae; frontoclypeal suture indistinct, not elevated, and weakly curved; smooth area anterior to eye as wide as long; ocular canthus long and narrow (1/3 of ocular diameter), impunctate and with a long terminal seta. Frons flat, with fine and dense punctures, with fine, partly dense, white, adpressed scales beside eyes and with a few yellow, long, erect setae. Eyes small, ratio diameter/interocular width: 0.57. Antenna with ten antennomeres; club with three antennomeres, 1.1 times as long as remaining antennomeres combined and straight. Mentum elevated and anteriorly flattened. Labrum moderately produced medially, distinctly emarginate medially, with two large, sharp teeth beside emargination.

Pronotum wide and trapezoidal, distinctly wider than long, widest at base, lateral margins slightly 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, blunt, almost obsolete; posterior angles acute; anterior margin straight, without anterior marginal line; surface densely and finely punctate, surface with dense, fine, white, short, adpressed scale-like setae and with long, yellow, erect setae; anterior and lateral margins with long dense setae; hypomeron distinctly carinate, carina weakly 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 weakly convex, with fine, irregularly dense punctures, dark spots completely smooth and glabrous; intervals with dense, fine, short, white, adpressed setae, intervals beside striae additionally with a fine, long, erect setae; epipleural edge robust, 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, metasternum and metacoxa finely densely setose, metacoxa additionally laterally with few robust setae; abdominal sternites finely and densely punctate, with a transverse row of coarse punctures, each bearing a short, robust seta, otherwise also finely densely setose. Mesosternum between mesocoxae almost as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.85. Pygidium weakly convex and dull, finely and densely punctate, with basally wide, smooth midline, with fine, white, dense, short, adpressed setae and fine, long, erect setae.

Legs 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 slender and long, widest shortly before apex, ratio of width/length: 1/4.4; dorsal margin sharply carinate, with two groups of spines, basal group at middle, apical group at three quarters of metatibial length, basally with a few single, robust setae; lateral face longitudinally concave, along middle finely and moderately densely punctate, without longitudinal wrinkles, with sparse, short, white, adpressed setae; ventral margin serrated, with four equidistant, robust setae; medial face sparsely punctate and glabrous; apex interiorly near tarsal articulation concavely truncate. Tarsomeres ventrally with sparse, minute setae, dorsally impunctate; metatarsomeres laterally not carinate, smooth, with a strongly serrated ridge ventrally; first metatarsomere as long as following two tarsomeres combined and distinctly longer than dorsal tibial spur. Protibia short, bidentate, external margin smooth; distal tarsomeres in holotype missing.

Aedeagus: Fig. 16H–K . Habitus: Fig. 16F–G .

Diagnosis. Pachyserica mutuo new species differs from all other Himalayan Pachyserica species by the long, narrow, and equally long parameres which are bent evenly ventrally, as well as by the strong, blunt tooth on the right side of the dorsal phallobasal apex.

Etymology. The name of this new species (noun in apposition) is derived from the name of its type locality Mutuo (Xizang).

Genbank accession numbers: Paratype (voucher: Se-XZ-7; Cox 1: PP977012).

Variation. Length: 11.2–11.5 mm, length of elytra: 7.9–8.4 mm, width:6.8–7.0 mm.Female:Body slightly larger, eyes smaller, ratio diameter/interocular width: 0.49; antennal club slightly shorter than remaining antennomeres combined; pygidium strongly convex at apex.

Figures

FIGURE 16. A–E: Pachyserica scalaris Arrow, 1946 (China: Yunnan: Zizhi vill.); F–K: P. motuo 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, E: habitus, dorsal view; F, G: habitus, lateral view. Scale bar: 0.5 mm. Habitus images not to scale.