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) Author Ahrens, Dirk 0000-0003-3524-7153 Zoologisches Forschungsmuseum A. Koenig, Adenauerallee 127, 53113 Bonn, Germany ahrens. dirk _ col @ gmx. de; https: // orcid. org / 0000 - 0003 - 3524 - 7153 ahrens.dirk_col@gmx.de Author Zhao, Ming-Zhi 0000-0002-3158-6177 College of Plant Protection, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, P. R. China zhaomzhai @ 126. com; https: // orcid. org / 0000 - 0002 - 3158 - 6177 zhaomzhai@126.com Author Pham, Phu Van 0000-0001-9369-6649 Institute of Ecology and Biological resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam phupham. iebr @ gmail. com; https: // orcid. org / 0000 - 0001 - 9369 - 6649 phupham.iebr@gmail.com Author Liu, Wan-Gang 0000-0003-3524-7153 Zoologisches Forschungsmuseum A. Koenig, Adenauerallee 127, 53113 Bonn, Germany ahrens. dirk _ col @ gmx. de; https: // orcid. org / 0000 - 0003 - 3524 - 7153 & SKLLQG, Institute of Earth and Environment, Chinese Academy of Sciences, Yanxiang Road 97, Yanta District, Xi’an 710061 P. R. China liuwangang @ ieecas. cn; https: // orcid. org / 0000 - 0003 - 4788 - 7967 & Zoologisches Forschungsmuseum A. Koenig, Adenauerallee 127, 53113 Bonn, Germany ahrens. dirk _ col @ gmx. de; https: // orcid. org / 0000 - 0003 - 3524 - 7153 ahrens.dirk_col@gmx.de text Zootaxa 2024 2024-08-01 5491 1 1 89 http://dx.doi.org/10.11646/zootaxa.5491.1.1 journal article 301609 10.11646/zootaxa.5491.1.1 34c72ca9-f976-4c79-a123-f93af60fa26c 1175-5334 13211849 0612E62C-A53D-42BE-8578-68EC77D34627 Pachyserica natmatoung Ahrens, Zhao, Pham & Liu , new species Fig. 17A–F Type material examined. Holotype ♂ “X-DA6415 / X-DA6415 Myanmar Chin State , Mt. Victoria Nat Ma Toung N.P. , rd. Mindal – Matupi , ca. 500 m , W 22 miles camp 21°26.427′N, 93°47.121″ E— 2286m leg. S. Löffler ; S. Naumann 20.v.2012 Pachyserica sp. TigerThai71 / Asia Sericini spec. 1349” ( ZFMK ) . Paratype : 1 ♂ “X-DA6415 / X-DA6415 Myanmar Chin State , Mt. Victoria Nat Ma Toung N.P , rd. Mindal – Matupi , ca. 500 m , W 22 miles camp 21°26.427′N, 93°47.121″ E 2286m leg. S. Löffler ; S. Naumann 20.v.2012 Pachyserica sp. TigerThai71” ( ZFMK ). Description of holotype . Length: 9.6 mm , length of elytra: 7.4 mm , width: 5.1 mm . Body oblong-oval and convex, dark brown, punctures of elytra, elytral stripes, and legs reddish brown, elytra with dark spots, antenna yellow, dorsal surface dull, partly with weak iridescent shine, with fine, dense, short, adpressed, white setae, long, fine, erect, yellow setae sparse, mainly only on head and a few on pronotum. Labroclypeus subrectangular, wider than long, widest at base, lateral margins weakly convex, anteriorly convex and convergent anteriorly, in anterior half more strongly convergent and convex; anterior angles convex; anterior margin distinctly but shallowly emarginate medially; margins weakly reflexed; surface flat, shiny, finely and densely punctate, with a few long, erect setae; frontoclypeal suture distinct, slightly elevated, and weakly curved; smooth area anterior to eye 1.2 times as wide as long; ocular canthus moderately long and narrow (1/4 of ocular diameter), impunctate and with a moderately long terminal seta. Frons flat, with fine and dense punctures, with fine, dense, white, adpressed scales and with a few yellow, long, erect setae. Eyes small, ratio diameter/interocular width: 0.57. Antenna with ten antennomeres; club with three antennomeres, 1.3 times as long as remaining antennomeres combined and straight. Mentum elevated and convex. 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 very slightly concave in basal half and strongly convergent anteriorly, slightly convexly bent at middle, in anterior half again straight and strongly convergent anteriorly; anterior angles weakly produced, blunt, slightly rounded in tip; posterior angles almost acute, slightly rounded in tip; anterior margin straight, without anterior marginal line; surface densely and finely punctate, sparely with larger punctures bearing sometimes (most abraded in holotype ) a long fine seta; otherwise surface with dense, fine, white, short, adpressed setae which are laterally denser and thicker, almost scale-like; anterior and lateral margins without long setae (abraded in holotype ); hypomeron distinctly carinate, carina weakly produced ventrally. Scutellum wide 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 posterior quarter, 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 additionally with fine, single, white, and longer scale-like 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 with fine and dense, adpressed, white setae, metasternal disc additionally with fine, long setae; 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 covered with fine, white, dense setae. Mesosternum between mesocoxae almost as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.28. Pygidium strongly convex and dull, finely and densely punctate, with wide, smooth midline, with fine, white, dense, short, adpressed setae and with 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 at apex, ratio of width/length: 1/5.1; 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, finely and very sparsely punctate, without longitudinal wrinkles, with a few single short, adpressed setae; ventral margin serrated, with three, almost 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; anterior claws symmetrical, basal tooth of inner claw normal. Aedeagus: Fig. 17A–D . Habitus: Fig. 17E–F . Female unknown. Diagnosis. Pachyserica matoung new species differs from P. collaris Ahrens, 2005 by the straight mesal margin of the left paramere, of which the external margin is, however, concave. In P. collaris , the mesal margin of the left paramere is distinctly concave, the external margin is straight and not narrowed after the basis. Etymology. The name of this new species (noun in apposition) is derived from the name of its type locality Nat Ma Toung N.P. ( Myanmar ). Variation. Length: 8.6–9.6 mm , length of elytra: 6.5–7.4 mm , width: 4.8–5.1 mm .