Pachyserica wangzizhaoi 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 : 47-48

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

Fig. 20A–E

Type material examined. Holotype ♂ “[ China] Guangdong Nanling Nature Reserve 2011.5.18 –21 Tian-Tian Yu leg.” ( SCAU) . Paratypes: 1 ♂ “ CHINA: Guangdong, Nanling N.R., Jiuchongshan 1031m 24.89396741°N, 113.04554002°E 2023.IV.28, Zi-Zhao Wang leg./ Se-XH-1” ( SCAU) , 2 ♂♂ “ CHINA: Guangdong, Nanling N.R., Jiuchongshan 1031m 24.89396741°N, 113.04554002°E 2023.IV.28, Zi-Zhao Wang leg.” ( CZMZ) , 1 ♀ “[ China] Guangdong, Nanling Nature Reserve 2017-V-31 ” ( SCAU) , 1 ♂, 2 ♀♀ “[ China] Guangdong, Nanling 2010.IV.26 Fen Gui” ( SCAU) , 2 ♀♀ “[ China] Guangdong, Nanling 2010.IV.26 Liu-Han Li” ( SCAU) , 2 ♀♀ “[ China] Guangdong, Nanling 2010.IV.26 Min Zheng” ( SCAU) .

Description of holotype. Length: 9.4 mm, length of elytra: 6.6 mm, width: 5.2 mm. Body oblong-oval and convex, including legs entirely reddish brown, 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, lanceolate setae, elytra additionally with sparse, longer but semierect setae.

Labroclypeus subrectangular, distinctly 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 weakly reflexed; surface flat, moderately shiny, coarsely and densely punctate, with dense, long, erect setae; frontoclypeal suture distinct, finely incised and flat, weakly curved; smooth area anterior to eye as wide as long, not shiny; ocular canthus moderately long and narrow (slightly longer than 1/3 of ocular diameter), with three moderately long setae in apical half. Frons flat, coarsely, densely punctate, with sparse, adpressed lanceolate setae, which are denser beside eyes, additionally also with dense, long, erect setae. Eyes large, ratio diameter/interocular width: 0.7. Antenna with ten antennomeres; antennomeres three to six almost as wide as long, antennomere seven transverse and very short, club with three antennomeres, two 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 wide and 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 acute, somewhat rounded at tip; anterior margin straight, with distinct and complete anterior marginal line; surface densely and finely punctate, a narrow midline and a rounded portion at each side impunctate, each puncture bearing a short, adpressed lanceolate 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, medial and apical areas 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, short, white, adpressed, lanceolate setae, additionally with fine, single, white, longer, 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, short setae, hypomeron, metasternum and metacoxa with short, dense, adpressed, lanceolate setae, metasternal disc and anteriorly 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, with a wide, impunctate midline, otherwise finely 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: 1/4.5; dorsal margin sharply carinate, with two groups of spines, basal group shortly before middle, apical group at three quarters of metatibial length, 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. 20A–C . Habitus: Fig. 20D, E . Female unknown.

Diagnosis. Pachyserica wangzizhaoi new species is similar to P. squamifera (Frey, 1972) and P. tianxuani new species. The former two species have the apex of the left paramere directed externally, while it is directed mesally in P. tianxuani . Furthermore, P. wangzizhaoi can be distinguished from P. squamifera (Frey, 1972) by the strongly concave left paramere.

Etymology. This species (noun in genitive case singular) is named after one of the collectors, Mr. Zi-Zhao Wang (SCAU, China).

Variation. Length: 9.0– 10.3 mm, length of elytra: 6.5–7.7 mm, width: 4.9–5.2 mm. Female: Antennal club as long as remaining antennomeres combined.

Figures

FIGURE 20. A–E: Pachyserica wangzizhaoi new species (holotype); A: aedeagus, left side lateral view; C: aedeagus, right side lateral view; B: parameres, dorsal view; D: habitus, dorsal view; E: habitus, lateral view. Scale bar: 0.5 mm. Habitus images not to scale.