Pachyserica dongnanensis Zhao & Ahrens, 2023

Zhao, Ming-Zhi & Ahrens, Dirk, 2023, New species of the tribe Sericini Kirby, 1837 from China, with further updates on their taxonomy and distribution (Coleoptera: Scarabaeidae: Sericinae), Zootaxa 5361 (2), pp. 181-220 : 187-189

Pachyserica dongnanensis Zhao & Ahrens , new species

( Figs 3B–D , 4A–C )

Type material examined. Holotype. ♂ ( SCAU), “ CHINA: Guangxi, Guilin, Xing’an, Mts. Yuechengling , 25°52′21″N, 110°25′2″E, 2008 m, 7.VI.2023, Yi-Teng Li leg.” Paratypes. 2♂♂, 1♀ ( CZMZ), “ CHINA: Guangxi, Guilin, Xing’an, Mts. Yuechengling , 25°52′21″N, 110°25′2″E, 2008 m, 7.VI.2023, Yi-Teng Li leg.” ; 4♂♂, 2♀♀ ( CZMZ), “ CHINA: Guangxi, Guilin, Xing’an, top of Maoershan , 25.866187°N, 110.413211°E, 2087 m, 23.V.2023, Xiao-Han Ye leg.” ; 1♂ ( SYSU, En-296335), “ Guangxi, Xing’an , Maoershan , 2010-v-25-30, Shuang Zhao, Bo Tong, Hong-Sheng Wu leg.” ; 1♂, 9♀♀ ( CZMZ), “ CHINA: Hunan, Nanshan National Park, Mt. Jinzishan , 26.1464913°N, 110.43110663°E, 1740 m, 2022.VI.6, Zhi-Hao Qi & Rong Xiang Su leg.” ; 1♂ ( SYSU), “ Guangdong, Lianzhou , Dadongshan 2011.5.29 -31 living leg.” ; 1♂ ( CZMZ), “ CHINA: Fujian, Sanming City , Youxi Co., Mt. Shiwangshan , Daopaiyan , 1100 m ,, 15.V.2021, Rong-Xiang Su leg.” ; 1♀ ( SCAU), “ CHINA: Fujian, Wuyishan, Longdu Village , 27.7286977°N, 117.7136053°E, 594 m, 9.V.2023 at light, Yu-Long Zhang leg.” ; 1♀ ( CZMZ), “ CHINA: Fujian, Wuyishan, Mt. Xianfengling, 1040 m, 10.V.2023 at light, Yu-Long Zhang leg.” ; 1♂ ( CZMZ), “ CHINA: Fujian, Wuyishan , nr. Masu Village , 27.7420687°N, 117.7268197°E, 938 m, 11.V.2023 at light, Yu-Long Zhang leg.” ; 1♂ ( MHNG), “CHINE 21.IV.46 Kuatun, Fukien leg. Tschung-Sen // Pachyserica albosignata Mos. det. D. Ahrens 2000 ” ; 1♂ ( NMPC), “Kuatun (2300 m) 27,40 n. Br. 117,40 ö. L. J. Klapperich 7.4. 1938 (Fukien)” ; 1♂, 1♀ ( IZAS), “[ China] Baishanzu, Qingyuan , Zhejiang, 18.IV.1994, 1300m, leg. Hong Wu, Min Lin ” ; 1♂, 1♀ ( IZAS), “[ China] Chameiyu, Baishanzu, Qingyuan , Zhejiang, 19.IV.1994, 1300m, leg. Hong Wu ”.

Description of the holotype. General. Body shape elongated ovoid, moderately convex, generally dark brown, with greenish toment, sutural interval of elytra reddish brown, abdomen iridescent; clypeus black, legs reddish brown (excluding metacoxa), as well as palpi and antennae yellowish brown, shiny. Setae yellowish brown, scale-like setae pale.

Head. Labroclypeus nearly rectangular, ratio of maximum length/ width: 1/ 1.57; lateral margins almost straight and subparallel, anterior angles rounded, anterior margin almost straight; margins strongly reflexed except for medial anterior margin; surface flat, with moderately dense and large punctures, covering some long erect setae; frontoclypeal suture finely incised, curved medially; smooth area anterior to eye large and flat, twice as wide as long; ocular canthus moderately long and very thin (slightly shorter than 1/3 of ocular diameter), with two short erect setae preapically. Frons flat, with moderately dense and minute punctures, each bearing a small, oblong or lanceolate seta, covering sparse, long and erect setae. Eyes very large, ratio diameter/ interocular width: 1.06. Antenna with ten antennomeres; antennomeres 3 to 5 equally as wide as long and tend to fuse, antennomere 7 transverse and short; club with three antennomeres, 1.6 times as long as remaining antennomeres combined and weakly reflexed. Mentum strongly and transversely elevated anteriorly. Labrum strongly produced, more prominent medially.

Pronotum subtrapezoidal, widest at base; lateral margins evenly curved and strongly convergent anteriad, slightly concave in posterior half; anterior angle broadly rounded, posterior angle acute; hypomeron carinate at base and strongly produced ventrally; anterior margin with a complete and fine marginal line; surface with evenly dense and large punctures, a longitudinal and impunctate midline reaches anterior and posterior margins, with several smaller and glabrous areas beside, each puncture bearing a small and oblong seta, anterior and lateral margins with long, erect setae.

Scutellum elongated triangular, apex somewhat rounded; basomedial and apical portions impunctate, other portions with moderately dense and small punctures, most of the punctures each bearing a lanceolate seta.

Elytra oval, widest at middle. Striae finely impressed, strial punctures moderately dense and large; intervals weakly convex, impunctate sections predominant, otherwise with scattered and small punctures, most of the punctures each bearing a lanceolate seta, either minute or short, forming transverse patches, a few patches at apical half with denser scale-like setae, surface scarcely bearing upright and larger oblong setae, a long, semi-erect seta near base. Epipleura wide, abruptly ending after the strongly curved external apical angle of elytron, with a row of dense and long semi-erect setae; elytral apex with a moderately long seta, posterior margin with a fine membranous rim composed of microtrichomes.

Ventral thoracic surface. Hypomeron with moderately dense and short setae, areas around procoxa bearing lanceolate setae; ventral mesothoracic surface densely punctate, with minute, recumbent setae and oblong setae; metasternum sparsely and finely punctate, each puncture bearing an erect short seta, punctures laterally denser and larger, each, including on metepisternum and metacoxa, bearing a lanceolate or oblong seta. Mesosternum between mesocoxae slightly narrower than width of mesofemur. Ratio of length of metepisternum/ metacoxa: 1/ 1.43.

Abdomen. Abdominal ventrites with moderately dense and large punctures, each bearing a minute and oblong seta, each ventrite with a sparse and transverse row of short, erect setae. Ultimate ventrite medially almost as long as penultimate one, with scattered and long setae, posterior margin medially with dense setae. Pygidium moderately convex, with impunctate midline, posterior margin weakly reflexed; surface with moderately dense and large punctures, each bearing a minute and lanceolate seta, some moderately long setae on sides and somewhat aggregated near apex.

Femora. Profemur with a row of moderately long setae near dorsal margin, and a sparse row of minute scale-like setae medially. Mesofemur dull, two longitudinal rows of sparse punctures each bearing a short seta, with a transverse ridge near anterior margin. Metafemur with uneven surface, sparsely punctate, some punctures each bearing a short recumbent seta; anterior margin moderately sharp, ventral posterior margin serrate except for basal fifth, dorsal posterior margin completely serrate, a row of short setae situated between the latter two margins.

Tibiae. Protibia moderately long, bidentate, tibial teeth acute, mesial lateral margin weakly convex. Metatibia widest shortly before apex, ratio of width/ length: 1/ 4.5; dorsal margin sharply carinate; lateral face densely and finely punctate, dorsally with two groups of spiniform setae not touching the dorsal carina, basal group at two fifths, distal group at three quarters of metatibial length, base with several minute setae; ventral margin serrate except for basal third, with three equidistant spiniform setae, basally with several minute setae; medial face glabrous; apex interiorly serrate, near tarsal articulation shallowly concave.

Tarsi. Protarsomeres short. Mesotarsomeres finely serrate ventrally. All metatarsomeres carinate laterally and serrate ventrally, first metatarsomere as long as following two tarsomeres combined and slightly shorter than twice dorsal tibial spur length. All tarsomeres sparsely and finely setose ventrally. Protarsal claws symmetric, basal tooth wider than distal one.

Male genitalia. Fig. 4A .

Variation. Male. The specimens from Fujian have larger and denser scale-like setae upon pronotum and elytra, forming more robust patches. Antennal club of the paratype from Guangdong twice as long as remaining antennomeres combined. Base of left paramere varies from convex ( Fig. 4B ) to truncated ( Fig. 4C ). Female. Similar to males but usually larger in size. Antennal club distinctly shorter, as long as remaining antennomeres combined; eyes smaller than in male, ratio diameter/ interocular width: 0.5.

Measurements. Length: 8.0– 9.7 mm in males (holotype 9.7 mm), 9.5–11.0 mm in females; length of elytra: 6.2–7.0 mm in males (holotype 6.9 mm), 6.8–8.2 mm in females; width: 4.6–5.8 mm in males (holotype 5.4 mm), 5.1–6.1 mm in females.

Diagnosis. Pachyserica dongnanensis Zhao & Ahrens , new species is closely similar to P. albosignata ( Moser, 1915) and P. nantouensis Kobayashi & Yu, 1993 . It can be distinguished from P. albosignata by the longer right paramere, which is 1.5 times as long as that of P. albosignata , and from P. nantouensis by the wider left paramere. In addition, the serrated endophallite pointed to right side in P. dongnanensis but pointed medially in P. albosignata ( Fig. 4D ).

Etymology. Dong’nan (Southeastern China, in a wide sense) refers to a geographic zone that includes Chinese provinces of Guangxi, Guangdong, Fujian and Zhejiang. This area vastly overlaps with the distribution range of the new species.

Figures

FIGURE 3. Habitus in dorsal view. A, Pachyserica albosignata (Moser, 1915), male (Guangdong); B, P. dongnanensis Zhao & Ahrens, new species, holotype; C, P. dongnanensis, male paratype (Guangdong); D, P. dongnanensis, female paratype (Fujian); E, P. jianfengensis Zhao & Ahrens, new species, holotype. Scale bar = 5 mm.

FIGURE 4. Aedeagus. A, Pachyserica dongnanensis Zhao & Ahrens, new species, holotype; B, P. dongnanensis, paratype (Guangxi); C, P. dongnanensis, paratype (Guangdong); D, P. albosignata (Moser, 1915), male (Guangdong); E, P. jianfengensis Zhao & Ahrens, new species, holotype. a, aedeagus in left lateral view; b, parameres in dorsal view; c, aedeagus in right lateral view. Scale bar = 1 mm.