Holotype: ♂ “ NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) - 20°12'N, 104°01'E; 11.iv.–15.v.2012; 1300-1900m; leg. C. Holzschuh Ankauf ZFMK Bonn 2012” (ZFMK). Paratypes: 135 ♂♂ “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) - 20°12'N, 104°01'E; 14.iv.–15.v.2012; 1300–1900m; leg. C. Holzschuh Ankauf ZFMK Bonn 2012/13” (ZFMK), 1 ♂ “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) ~20°12'N, 104°01'E; 1300–1900m; 01.–31.V.2011; leg. C. Holzschuh Ankauf ZFMK Bonn 2011” (ZFMK), 27 ♂♂ “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) - 20°12'N, 104°01'E; 11.iv.-15.v.2012; 1300–1900m; leg. C. Holzschuh Ankauf ZFMK Bonn 2012” (ZFMK), 13 ♂♂ “Laos-NE, Houa Phan prov., 20°13'09–19''N, 103°59'54''-104°00'03''E, 1480–1510m Phou Pane Mt., 22.IV.–14.V.2008 Vit Kubáň leg. (NMPC), 1 ♂ “Laos-NE, Houa Phan prov., 20°13'09–19''N, 103°59'54''-104°00'03''E, 1480–1510m Phou Pane Mt., 22.IV.–14.V.2008 Vit Kubáň leg.” (NMPC).

Body length: 7.4 mm, length of elytra: 5.9 mm, width: 4.1 mm. Body oval, legs dark brown, elytra and dorsal surface black with greenish shine, with a brown spot on each side of pronotum, dull, with minute, moderately dense setae and sparse, long, erect setae interspersed (Fig. 1D).

Labroclypeus subrectangular and short, widest at middle, lateral margins weakly curved and convergent toward base, anterior angles broadly rounded, lateral border and ocular canthus producing a distinct obtuse angle, anterior margin weakly reflexed, straight, surface moderately convex medially and moderately shiny, coarsely and densely punctate, with several long, erect setae; frontoclypeal suture distinctly impressed and moderately curved, smooth area anterior to eye 1.5 times as wide as long; ocular canthus moderately short and robust, finely and densely punctate, with a short terminal seta. Frons with coarse, dense punctures, irregularly interspersed with fine ones, with sparse, erect setae, impunctate on midline. Eyes moderately large, ratio of diameter / interocular width: 0.71. Antenna brown, with ten antennomeres; club with four antennomeres, slightly longer than remaining antennomeres combined, first joint of club slightly shorter than club. Mentum elevated and flattened anteriorly.

Pronotum moderately wide, widest at base, lateral margins strongly curved and convergent anteriorly, weakly sinuate before posterior angles, anterior angles not produced and strongly rounded, nearly obsolete, posterior angles nearly right-angled, anterior margin almost straight, with distinct and fine marginal line, basal margin moderately curved, without marginal line, base with two shallow impressions on each side at a quarter of width from lateral margin; surface with moderately dense and coarse punctures each bearing a minute seta, not impressed on midline, without transverse impression behind middle; anterior and lateral borders sparsely setose; hypomeron carinate, basal margin of hypomeron strongly produced ventrally. Scutellum subtriangular, apex weakly rounded, with fine and dense punctures, medially smooth, with minute setae.

Elytra oblong, widest at middle, striae distinctly impressed and finely densely punctate; intervals moderately convex, with fine and sparse punctures concentrated along striae, punctures minutely setose, odd intervals with single, coarse punctures each bearing a strong erect seta; epipleural edge moderately strong, ending at strongly convex external apical angle of elytra, epipleura densely setose, apical border chitinous, without short microtrichomes.

Ventral surface dull, with large, dense punctures and dense, short, adpressed setae. Metacoxa partly glabrous, with fine adpressed setae laterally. Abdominal sternites finely and densely punctate, with fine, short setae, each sternite with indistinct transverse row of coarse punctures each bearing a short robust seta. Mesosternum between mesocoxae as wide as mesofemur, with numerous strong setae on an indistinct semicircular carina. Ratio of length of metepisternum / metacoxa: 1 / 1.75. Pygidium long, apically produced and strongly convex, with fine, dense punctures and fine setae, interspersed with a few robust punctures each bearing a robust seta, without smooth midline.

Legs moderately slender and moderately shiny; femora finely densely punctate and densely setose, with two longitudinal rows of longer and more robust setae; anterior edge of metafemur acute lacking an adjacent serrated line, posterior margin weakly convex, with a few fine setae medially, weakly widened in apical half ventrally but not serrate, serrate dorsally, with short setae. Metatibia moderately broad, convexly widened at middle, ratio width / length: 1 / 3, dorsally sharply carinate, with two groups of spines, basal group at one third, apical one at two thirds of metatibial length, with a few single spines in punctures basally; lateral face longitudinally convex, with dense and coarse punctures, some of them longitudinally impressed, ventral edge serrate; medial face impunctate and smooth, apex interiorly near tarsal articulation sharply truncate. Tarsomeres glabrous and finely punctate dorsally, with sparse, short setae ventrally; metatarsomeres with strong longitudinal impressions dorsally, with a strongly serrated ridge ventrally, with a strong longitudinal carina laterally, first metatarsomere shorter than following two tarsomeres combined and twice as long as dorsal tibial spur. Protibia short, bidentate, protarsal claws symmetrical.

Fig. 1A–C.

Gastroserica carolusi sp. n. is very similar to Gastroserica mausonensis Ahrens, 2000, from northern Vietnam; both species may be principally distinguished by shape of parameres: in the new species the lateral process of phallobase is shorter, the ventral process of left paramere is strongly reduced, and the lateral short tooth of the right paramere is displaced behind apical half.

The new species is named after one of its collectors, Carous Holzschuh, who donated many Sericini specimens from his Phou Pan collecting to the ZFMK.

Body length: 7.1–7.8 mm, length of elytra: 5.2–5.9 mm, width: 4.1–4.2 mm. Colour quite variable, from entirely black to yellowish brown with dorsal surface reddish brown with darker frons and pronotal disc, the latter form sometimes with sutural and lateral elytral intervals black, sometimes also 4th interval partly black and the pronotum with a narrow yellow midline. Blackish ventral surface is seen with either reddish or black dorsal surface.

The species occurs syntopically with Gastroserica marginalis (Brenske, 1894), from which female specimens cannot be distinguished. Therefore, we refrained from assigning female specimens to either species.

Holotype ♂ “Fengdu, Shiping, Sichuan, 2.VI.1994, 610m, leg. Zhang Youwei, light trap” (IZAS).

Body length: 7.3 mm, length of elytra: 5.5 mm, width: 4.0 mm. Body oval, including legs yellowish brown, head and disc of pronotum darker, dorsal surface moderately shiny, with sparse, long, erect setae (Fig. 1H).

Labroclypeus subrectangular and short, widest at middle, lateral margins weakly curved, convergent toward base, anterior angles broadly rounded, lateral border and ocular canthus producing a distinct obtuse angle, anterior margin weakly reflexed and straight, surface moderately convex medially and moderately shiny, coarsely and densely punctate, with several long, erect setae; frontoclypeal suture distinctly impressed and moderately curved, smooth area anterior to eye almost twice as wide as long; ocular canthus moderately short and strong, finely and densely punctate, with two terminal setae. Frons with coarse, dense punctures, with fine punctures irregularly interspersed, with dense erect setae. Eyes moderately large (in holotype slightly deformed), ratio of diameter / interocular width: 0.67. Antenna with ten antennomeres; club with four antennomeres, as long as remaining antennomeres combined, first joint of club slightly shorter than club. Mentum elevated and flattened anteriorly.

Pronotum rectangular, widest just before base, lateral margins nearly evenly convergent anteriorly, anterior angles strongly rounded, not produced, nearly obsolete; posterior angles blunt; anterior margin straight, with a distinct, fine marginal line, basal margin moderately curved, without marginal line, base with a shallow impressions on each side beside middle; surface with dense, fine punctures and with minute setae, disc beside midline widely and indistinctly dark, impunctate along midline but not impressed, with a very shallow and indistinct transverse impression behind middle; anterior and lateral borders setose; hypomeron carinate, basal margin of hypomeron strongly produced ventrally. Scutellum subtriangular, apex weakly rounded, with fine and dense punctures, smooth medially, with minute setae.

Elytra oblong, widest at middle, striae distinctly impressed and finely densely punctate; intervals convex, with fine and sparse punctures concentrated along striae, minutely setose in punctures, odd intervals with single coarse punctures each bearing a strong, erect seta; epipleural edge moderately strong, ending at strongly rounded external apical angle of elytra, epipleura densely setose, apical border chitinous, without short microtrichomes.

Ventral surface with large, dense punctures and dense, short adpressed setae. Metacoxa partly glabrous, with fine adpressed setae laterally. Abdominal sternites finely and densely punctate, with fine, short setae, each sternite with indistinct transverse row of coarse punctures each bearing a short robust seta. Mesosternum between mesocoxae as wide as mesofemur, with numerous strong setae. Ratio of length of metepisternum / metacoxa: 1 / 2.0. Pygidium long, apically produced and strongly convex, with fine, dense punctures and fine setae interspersed with few robust punctures each bearing a robust seta, without smooth midline.

Legs moderately slender and shiny; femora finely densely punctate and setose, with two longitudinal rows of setae; anterior edge of metafemur acute, lacking an adjacent serrated line, posterior margin weakly convex, with a few fine setae medially, weakly widened in apical half ventrally but not serrate, serrate dorsally, with short setae. Metatibia moderately broad, convexly widened at middle, ratio width / length: 1 / 3, sharply carinate dorsally, with two groups of spines, basal group at one third, apical one at two thirds of metatibial length, with a few single spines in punctures basally; lateral face longitudinally convex, with moderately dense and fine, minutely setose punctures, some of them longitudinally impressed, ventral edge serrate; medial face impunctate and smooth, apex sharply truncate interiorly near tarsal articulation. Tarsomeres glabrous and finely punctate dorsally, with sparse, short setae ventrally; metatarsomeres with strong longitudinal impressions dorsally, with a strongly serrated ridge ventrally and a strong longitudinal carina laterally, first metatarsomere shorter than following two tarsomeres combined and twice as long as dorsal tibial spur. Protibia short, bidentate, protarsal claws symmetrical.

Fig. 1E–G.

The new species is most similar to Gastroserica sichuana Ahrens, 2000, in shape of male genitalia and external morphology. It differs distinctly in the median process of the left paramere being shorter, as well as the right paramere being bent ventrally at the apex.

Named after the type locality, Fengdu.

Holotype ♂ “Mt. Fengyangshan, Longquan, Zhejiang, 25. VII.-1. VIII. 2007, leg. Liu Haoyu, Gao Zhenhua” (HBUM). Paratype: 1 ♂ “Mts. Fengyangshan, Zhejiang, 31.VII.2008, 1089-1168m, leg. Yang Juan” (IZAS).

Body length: 7.2 mm, length of elytra: 5.6 mm, width: 3.9 mm. Body oval, dark brown, legs, antenna, labroclypeus, midline and lateral margins of pronotum and a moderately wide longitudinal stripe on elytra yellowish brown, dorsal surface moderately shiny, with moderately dense, long, erect setae (Fig. 1L).

Labroclypeus subrectangular and short, widest at middle, lateral margins weakly curved, weakly convergent toward base, anterior angles broadly rounded, lateral border and ocular canthus producing a distinct obtuse angle, anterior margin weakly reflexed, weakly sinuate medially, surface moderately convex medially and moderately shiny, finely and sparsely punctate, with a few coarse punctures, each bearing a long erect seta, interspersed; frontoclypeal suture distinctly impressed and moderately curved, smooth area anterior to eye 1.6 times as wide as long; ocular canthus moderately short and strong, finely and densely punctate, with a fine terminal seta. Frons with coarse, partly very dense punctures, with a few short erect setae beside eyes and behind frontoclypeal suture. Eyes moderately large, ratio of diameter / interocular width: 0.63. Antenna with ten antennomeres; club with four antennomeres, slightly longer than remaining antennomeres combined, first joint of club slightly shorter than club. Mentum elevated and flattened anteriorly.

Pronotum rectangular, widest at base, lateral margins strongly convergent in anterior half, weakly sinuate before posterior angles, anterior angles not produced and strongly rounded, nearly obsolete, posterior angles nearly blunt, anterior margin straight, with a distinct and fine marginal line, basal margin moderately curved, without marginal line; base with a shallow impressions on each side beside middle; surface with dense and fine punctures, with minute setae in punctures, weakly impressed on midline, with a distinct transverse impression behind middle; anterior and lateral borders setose; hypomeron carinate, basal margin of hypomeron strongly produced ventrally. Scutellum subtriangular, apex weakly rounded, with fine and dense punctures, smooth medially, with a few minute setae in punctures.

Elytra oblong, widest at middle, striae distinctly impressed and finely densely punctate; intervals convex, with fine and sparse punctures concentrated along striae, punctures minutely setose, odd intervals with single coarse punctures each bearing a strong erect seta, a light yellowish stripe covers intervals V, III (posterior two thirds), IV, and VI (anterior quarter); epipleural edge moderately strong, ending at strongly rounded external apical angle of elytra, epipleura densely setose, apical border chitinous, without short microtrichomes.

Ventral surface dull, with large, dense punctures and dense, short, adpressed setae. Metacoxa partly glabrous, with fine adpressed setae laterally. Abdominal sternites finely and densely punctate, with fine, short setae, each sternite with indistinct transverse row of coarse punctures each bearing a short strong seta. Mesosternum between mesocoxae as wide as mesofemur, with numerous strong setae. Ratio of length of metepisternum / metacoxa: 1 / 1.71. Pygidium long, apically produced and strongly convex, with fine, dense punctures and fine setae interspersed with a few robust punctures each bearing a robust seta, without smooth midline.

Legs moderately slender and shiny; femora finely, densely punctate and setose, with two longitudinal rows of longer setae; anterior edge of metafemur acute lacking an adjacent serrated line, posterior margin weakly convex, with a few fine setae medially, weakly widened in apical half ventrally but not serrate, serrate dorsally, with short setae. Metatibia moderately broad, convexly widened at middle, ratio width / length: 1 / 3.16, dorsally sharply carinate, with two groups of spines, basal group at one third, apical one at two thirds of metatibial length, with a few single spines in punctures basally; lateral face longitudinally convex, with dense and moderately coarse, longitudinally impressed punctures, ventral edge serrate; medial face impunctate and smooth, apex sharply truncate interiorly near tarsal articulation. Tarsomeres glabrous and finely punctate dorsally, with sparse, short setae ventrally; metatarsomeres with strong longitudinal impressions dorsally, with a strongly serrated ridge ventrally, with a strong longitudinal carina laterally, first metatarsomere slightly shorter than following two tarsomeres combined and twice as long as dorsal tibial spur. Protibia short, bidentate, protarsal claws symmetrical.

Fig. 1I–K.

Gastroserica haoyui sp. n. differs from all other known Gastroserica species by the left paramere being s-shaped.

This new species is named after its collector, Liu Haoyu.

Body length: 7.2 mm, length of elytra: 5.5–5.6 mm, width: 3.9–4.3 mm. Body oval, pale brown.

Holotype ♂ “Yinshanzhan, Jinxiu, Guangxi, 1100m, 10.V.1999, leg. Li Wenzhu” (IZAS).

Body length: 8.8 mm, length of elytra: 6.7 mm, width: 4.4 mm. Body oval, pronotum, dark brown, surface dull, dorsal surface with moderately dense, long, erect setae (Fig. 2D).

Labroclypeus subrectangular and short, widest at base, lateral margins convex and moderately convergent from base to anterior angles, anterior angles broadly rounded, lateral border and ocular canthus producing a distinct obtuse angle, anterior margin weakly concavely sinuate and weakly reflexed, surface moderately convex medially, moderately shiny, coarsely and sparsely punctate, with several long, erect setae; frontoclypeal suture distinctly impressed and moderately curved, smooth area anterior to eye slightly wider than long; ocular canthus moderately short and strong, finely and densely punctate, terminal seta lacking. Frons coarsely and moderately densely punctate, with fine punctures irregularly interspersed, sparsely setose, most setae abrased in holotype. Eyes moderately large, ratio of diameter / interocular width: 0.52. Antenna missing in holotype. Mentum elevated and flattened anteriorly.

Pronotum rectangular, widest at middle, lateral margins strongly convergent anteriorly, weakly sinuate before posterior angles, anterior angles not produced and strongly rounded, nearly obsolete, posterior angles moderately blunt, anterior margin straight, with a fine marginal line, basal margin moderately curved, without marginal line, base with a weak impression on each side; surface with moderately dense and moderately coarse punctures, punctures with minute setae, moderately impressed on midline, with a weak, transverse impression behind middle; anterior and lateral borders setose; hypomeron carinate, basal margin of hypomeron strongly produced ventrally. Scutellum subtriangular, apex weakly rounded, with fine and dense punctures, smooth medially, with a few minute setae in punctures.

Elytra oblong, widest at middle, striae distinctly impressed and finely densely punctate; intervals weakly convex, with fine and sparse punctures concentrated along striae, punctures minutely setose, odd intervals with single coarse punctures, each bearing a strong erect seta; epipleural edge moderately strong, ending at strongly rounded external apical angle of elytra, epipleura densely setose, apical border chitinous, without short microtrichomes.

Ventral surface with large and dense punctures and dense, short, adpressed setae. Metacoxa partly glabrous, with fine adpressed setae laterally. Abdominal sternites finely and densely punctate, with fine, short setae, each sternite with indistinct transverse row of coarse punctures, each bearing a short strong seta. Mesosternum between mesocoxae as wide as mesofemur, with numerous strong setae. Ratio of length of metepisternum / metacoxa: 1 / 1.79. Pygidium long, apically produced and strongly convex, with fine, dense punctures and fine setae interspersed with a few robust punctures each bearing a robust seta, without smooth midline.

Legs moderately slender and shiny; femora finely densely punctate and setose, with two longitudinal rows of setae; anterior edge of metafemur acute, lacking an adjacent serrated line, posterior margin weakly convex, with a few fine setae medially, weakly widened ventrally in apical half but not serrate, serrate dorsally, with short setae. Metatibia moderately broad, convexly widened at middle, ratio width / length: 1 / 3.33, dorsally sharply carinate, with two groups of spines, basal group at one third, apical one at two thirds of metatibial length, basally with a few single spines in punctures; lateral face longitudinally convex, with moderately dense and fine, longitudinally impressed punctures, ventral edge serrate; medial face impunctate and smooth, apex interiorly near tarsal articulation sharply truncate. Meso and metatarsomeres missing in holotype.

Fig. 2A–C.

The species somewhat resembles Gastroserica kabakovi Ahrens, 2002, in genital morphology. It differs mainly in the details of paramere shape: in the new taxon, the left paramere is distinctly longer than it is in Gastroserica kabakovi, while its two processes are more widely divergent, with the external one reflexed ventrally along its own axis.

Named after the type locality, Jinxiu.

Holotype: ♂ “Libo, Guizhou, V.1998, No.1-028, 3-017” (IZAS). Paratype: 1 ♀ “Libo, Guizhou, V.1998, No.1-028, 3-017” (IZAS).

Body length: 8.9 mm, length of elytra: 6.5 mm, width: 4.5 mm. Body oval, dark brown, ventral surface, labroclypeus and sides of pronotum including footstalk of antenna reddish, dorsal surface dull, with moderately dense, long, erect setae (Fig. 2H).

Labroclypeus subrectangular and short, widest at middle, lateral margins weakly curved and convergent towards base, anterior angles broadly rounded, lateral border and ocular canthus producing a distinct obtuse angle, anterior margin weakly reflexed, nearly straight, surface moderately convex medially and moderately shiny, finely and densely punctate, with numerous long, erect setae; frontoclypeal suture distinctly impressed and moderately curved, smooth area anterior to eye almost twice as wide as long; ocular canthus moderately short and strong, finely and densely punctate, with one or two terminal setae. Frons with coarse, dense punctures, with fine punctures irregularly interspersed, with dense erect setae. Eyes moderately large, ratio of diameter / interocular width: 0.68. Antenna with ten antennomeres; club with four antennomeres, as long as remaining antennomeres combined, antennomeres of club subequal in length. Mentum elevated and flattened anteriorly.

Pronotum subtrapezoidal, widest at base, lateral margins strongly convergent in anterior half, almost subparallel in basal half and slightly sinuate before posterior angles, anterior angles not produced and strongly rounded, nearly obsolete, posterior angles moderately sharp, anterior margin almost straight, with a distinct, fine marginal line, basal margin without marginal line; base with a shallow impressions on each side beside middle; surface with moderately dense and moderately coarse punctures, punctures with minute setae, without transverse or longitudinal impressions; anterior and lateral borders setose; hypomeron carinate, basal margin of hypomeron strongly produced ventrally. Scutellum subtriangular, apex weakly rounded, with fine and dense punctures, smooth medially, with a few minute setae in punctures.

Elytra oblong, widest at middle, striae distinctly impressed and finely densely punctate; intervals moderately convex, with fine and sparse punctures concentrated along striae, punctures minutely setose, odd intervals with single coarse punctures each bearing a strong erect seta; epipleural edge moderately strong, ending at strongly rounded external apical angle of elytra, epipleura densely setose, apical border chitinous, without short microtrichomes.

Ventral surface with large and dense punctures and dense, short, adpressed setae. Metacoxa partly glabrous, with fine adpressed setae laterally. Abdominal sternites finely and densely punctate, with fine, short setae, each sternite with indistinct transverse row of coarse punctures each bearing a short robust seta. Mesosternum between mesocoxae as wide as mesofemur, with numerous strong setae. Ratio of length of metepisternum / metacoxa: 1 / 1.78. Pygidium long, apically produced and strongly convex, with fine, dense punctures and fine setae interspersed with a few robust punctures each bearing a robust seta, without smooth midline.

Legs moderately slender and shiny; femora finely densely punctate and setose, with two longitudinal rows of setae; anterior edge of metafemur acute, lacking an adjacent serrated line, posterior margin weakly convex, with a few fine setae medially, weakly widened in apical half ventrally but not serrate, serrate dorsally, with short setae. Metatibia moderately broad, convexly widened at middle, ratio width / length: 1 / 3.0, dorsally sharply carinate, with two groups of spines, basal group at one third, apical one at two thirds of metatibial length, with a few single spines in punctures basally; lateral face longitudinally convex, with dense and fine, longitudinally impressed punctures, ventral edge serrate; medial face impunctate and smooth, apex interiorly near tarsal articulation sharply truncate. Metatarsomeres missing in holotype.

Fig. 2E–G.

The new species is, to some extent, similar to Gastroserica angustula Brenske, 1897, in genital morphology, but differs in being slightly larger in body size and in having the lateral apical apophysis of phallobase shorter, the right paramere lacking a small lateral tooth, and the left paramere being curved dorsally.

Named after the type locality, Libo.

Female: Body length: 9.1 mm, length of elytra: 6.8 mm, width: 4.5 mm. Body oval, reddish brown, antenna pale brown. Eyes small, ratio of diameter / interocular width: 0.58. Ratio of length of metepisternum / metacoxa: 1 / 1.91. Metatibia moderately broad, convexly widened at middle, ratio width / length: 1 / 3.2. Tarsomeres glabrous and finely punctate dorsally, with sparse, short setae ventrally; metatarsomeres with strong longitudinal impressions dorsally, with a strongly serrated ridge ventrally, with a strong longitudinal carina laterally, first metatarsomere as long as following two tarsomeres combined and twice as long as ventral tibial spur.

Holotype: ♂ “Defu, Napo, Guangxi, 1350m, 18.VI.2000, leg. Li Wenzhu” (IZAS). Paratypes: 1 ♂ “Fulong, Fangcheng City, Guangxi, 500m, 24.V.1999, leg. Liu Dajun” (IZAS), 1 ♀ “Fulong, Fangcheng City, Guangxi, 24.V.1999, 500m, leg. Liu Dajun” (IZAS).

Body length: 7.8 mm, length of elytra: 6.0 mm, width: 3.9 mm. Body oval, yellowish brown, frons, two large maculae and 4th and lateral intervals of elytra as well as abdomen darker, dorsal surface moderately shiny, frons and disc of pronotum with some greenish sheen, with moderately dense, long, erect setae (Fig. 2L).

Labroclypeus subellyptical, widest at middle, lateral margins convex, strongly convergent toward base and to broadly rounded anterior angles, lateral border and ocular canthus producing a distinct obtuse angle, anterior margin weakly reflexed, straight, surface moderately convex medially and moderately shiny, coarsely and densely punctate, with several long, erect setae; frontoclypeal suture distinctly impressed and moderately curved, smooth area anterior to eye 1.3 times as wide as long; ocular canthus moderately short and strong, finely and densely punctate, with two terminal setae. Frons with coarse, dense punctures and with fine, dense punctures regularly interspersed, covered with dense erect setae. Eyes moderately large, ratio of diameter / interocular width: 0.63. Antenna with ten antennomeres; club with four antennomeres, slightly longer than remaining antennomeres combined. Mentum elevated and flattened anteriorly.

Pronotum moderately wide, widest at base, lateral margins strongly convergent in anterior half, subparallel in basal half and weakly sinuate before posterior angles, anterior angles not produced and strongly rounded, nearly obsolete, posterior angles moderately sharp, anterior margin straight, with a distinct, fine marginal line, basal margin without marginal line; surface with dense and moderately fine punctures, punctures with minute setae, without impressions; anterior and lateral borders setose; hypomeron carinate, basal margin of hypomeron strongly produced ventrally. Scutellum subtriangular, apex weakly rounded, with fine and dense punctures, medially smooth, with a few minute setae in punctures.

Elytra oblong, widest at posterior third, striae distinctly impressed and finely densely punctate; intervals moderately convex, with fine and sparse punctures concentrated along striae, punctures minutely setose, odd intervals with single coarse punctures, each bearing a strong erect seta, sutural and 4th interval as well as lateral two intervals blackish; epipleural edge moderately strong, ending at strongly rounded external apical angle of elytra, epipleura densely setose, apical border chitinous, without short microtrichomes.

Ventral surface with large and dense punctures and dense, short, adpressed setae. Metacoxa partly glabrous, with fine adpressed setae laterally. Abdominal sternites finely and densely punctate, with fine, short setae, each sternite with indistinct transverse row of coarse punctures, each bearing a short strong seta. Mesosternum between mesocoxae as wide as mesofemur, with numerous strong setae. Ratio of length of metepisternum / metacoxa: 1 / 2.0. Pygidium long, apically produced and strongly convex, with fine, dense punctures and fine setae interspersed with a few robust punctures each bearing a robust seta, without smooth midline.

Legs moderately slender and shiny; femora finely densely punctate and setose, with two longitudinal rows of setae; anterior edge of metafemur acute lacking an adjacent serrated line, posterior margin weakly convex, with a few fine setae medially, weakly widened ventrally in apical half but not serrate, serrate dorsally, with short setae. Metatibia moderately broad, convexly widened at middle, ratio width / length: 1 / 3.33, dorsally sharply carinate, with two groups of spines, basal group at one third, apical one at two thirds of metatibial length, with a few single spines in punctures basally; lateral face longitudinally convex, with dense and fine, longitudinally impressed punctures, ventral edge serrate; medial face impunctate and smooth, apex interiorly near tarsal articulation sharply truncate. Tarsomeres glabrous and finely punctate dorsally, with sparse, short setae ventrally; metatarsomeres with strong longitudinal impressions dorsally, with a strongly serrated ridge ventrally, with a strong longitudinal carina laterally, first metatarsomere as long as following two tarsomeres combined and twice as long as dorsal tibial spur. Protibia short, bidentate, protarsal claws symmetrical.

Fig. 2I–K.

The new species is very similar to Gastroserica pickai Ahrens, 2000, from northern Vietnam in external and genital morphology. The new taxon differs from Gastroserica pickai in having much more narrow parameres.

The new species is named after one of its collectors, Li Wenzhu.

Body length: 7.1–7.8 mm, length of elytra: 5.3–6.0 mm, width: 3.9–4.1 mm. Female: smooth area anterior to eye as wide as long; club with three antennomeres, as long as remaining antennomeres combined.

Holotype. ♂ “Guangxi, Damingshan, 20.V.2011, 1230m, 23°30'N, 108°26'E, leg. Zhang Youwei” (IZAS).

Body length: 6.7 mm, length of elytra: 4.7 mm, width: 3.8 mm. Body oval, pronotum and ventral surface yellowish brown, frons and two spots on disc of pronotum darker, elytra reddish brown, lateral intervals darker, abdomen dark brown to grey. Dorsal surface moderately shiny, with sparse setae (Fig. 3D).

Labroclypeus subelliptical, widest at middle, lateral margins strongly convex and convergent toward base, anterior angles broadly rounded, lateral border and ocular canthus producing a distinct obtuse angle, anterior margin weakly reflexed and straight, surface moderately convex medially and moderately shiny, coarsely and densely punctuate; frontoclypeal suture weakly impressed and moderately curved, smooth area anterior to eye almost 1.3 times as wide as long; ocular canthus moderately long and narrow, finely and densely punctate, without terminal seta. Frons with a few coarse and fine punctures, with a few short setae behind frontoclypeal suture and on posterior portion. Eyes moderately large, ratio of diameter / interocular width: 0.65. Antenna with ten antennomeres; club with four antennomeres, as long as remaining antennomeres combined. Mentum elevated and flattened anteriorly.

Pronotum rectangular, widest at base, lateral margins nearly evenly convergent anteriorly, slightly concavely sinuate before posterior angles, anterior angles strongly rounded, not produced, nearly obsolete, posterior angles blunt, anterior margin straight, with a distinct, fine marginal line, basal margin moderately curved, without marginal line; surface with dense and fine punctures and with minute, adpressed setae; anterior border sparsely setose, setae of lateral margin lacking; hypomeron carinate, basal margin of hypomeron moderately produced ventrally. Scutellum subtriangular, apex weakly rounded, with fine and dense punctures, smooth medially, with minute setae.

Elytra oblong, widest at middle, striae distinctly impressed and finely densely punctate; intervals convex, with fine and sparse punctures concentrated along striae, minutely setose in punctures, odd intervals with larger, single punctures whose setae are abraded, however, lateral intervals with a few setae remaining; epipleural edge moderately strong, ending at strongly rounded external apical angle of elytra, epipleura densely setose, apical border chitinous, without short microtrichomes.

Ventral surface with large, dense punctures and dense, short adpressed setae. Metacoxa setose, with several strong adpressed setae laterally. Abdominal sternites finely and densely punctate, with fine, short setae, each sternite with indistinct transverse row of coarse punctures each bearing a short robust seta. Mesosternum between mesocoxae as wide as mesofemur, with numerous strong setae. Ratio of length of metepisternum / metacoxa: 1 / 1.93. Pygidium long, apically produced and strongly convex, with fine, dense punctures and fine setae interspersed with a few robust punctures each bearing a robust seta, without smooth midline.

Legs moderately strong and shiny; femora finely densely punctate and setose, with two longitudinal rows of setae; anterior edge of metafemur acute lacking an adjacent serrated line, posterior margin weakly convex, with a few fine setae medially, weakly widened in apical half ventrally but not serrate, serrate dorsally, with short setae. Metatibia moderately broad, convexly widened at middle, ratio width / length: 1 / 3, dorsally sharply carinate, with two groups of spines, basal group at one third, apical one at two thirds of metatibial length, with a few single spines in punctures basally; lateral face longitudinally convex, with moderately dense and fine, minutely setose punctures, some of them longitudinally impressed, ventral edge serrate; medial face impunctate and smooth, apex interiorly near tarsal articulation sharply truncate. Tarsomeres missing on holotype.

Fig. 3A–C.

The new species is most closely related to Gastroserica nikodymi Ahrens, 2000, in external appearance and genital morphology. It differs significantly in the shape of the right lateral process of phallobase, which is sharply pointed apically; the parameres are quite different: the left one is longer and evenly curved ventrally, the right one is lacking a basal lobe.

The new species is named after the type locality, Damingshan Mountains.

1 ♂ “Mts. Leigongshan, Leishan, Guizhou, 30.VI.1988, 1550m, leg. Wang Shuyong” (IZAS), 1 ♂ “Mts. Tianpingshan, Longsheng, Guangxi, 9.VI.1963, 740m, leg. Wang Shuyong” (IZAS), 1 ♂ “Taiyuan, Pengshui, Sichuan, 10.VII.1989, 850m, leg. Yang Longlong” (IZAS), 1 ♂ “Baiyan, Longsheng, Sichuan, 23.VI.1963, 1150m, leg. Wang Shuyong” (IZAS), 1 ♂ “Mts. Jiulianshan, Jiangxi, 20.VI.1979, 850m, leg. Zhang Youwei” (IZAS). 1 ♂ “Mts. Leigongshan, Leishan, Guizhou, 1.VII.1988, 1050m, leg. Wang Shuyong” (IZAS).

3 ♂♂ “Taiyuan, Pengshui, Sichuan, 10, 12.VII.1989, 800, 850m, leg. Yang Longlong” (IZAS), 2 ♂♂ “Mts. Fanjingshan, Jiangkou, Guizhou, 12.VIII.1988, 530m, leg. Wang Shuyong” (IZAS), 1 ♂ “Mts. Tianpingshan, Longsheng, Guangxi, 4.VI.1963, 740m, leg. Shi Yongshan” (IZAS), 6 ex. “CH-Ghuizhou NE 27.V.–3.VI. 20 km NW of Jiankou 1995 Fanjing Shan- Kuaichang E. Jendek & O. Šauša” (CP).

1 ♂ “Mts. Chebaling, Shixing, Guangdong, 25.IV.1991, leg. Li Fasheng” (CAU), 1 ♂ “Huangxizhou, Mts. Wuyishan, Fujian, 27.V.2004, leg. Yuan Caixia, Li Jing” (HBUM), 8 ex. “China: Fujian Province; Mt. Liang-shan-ding, Wuping County, July 2–13, 2009 local collectors Ankauf via Li Jingke 2010” (ZFMK).

1 ♂ “Mts. Tianping, Longsheng, Guangxi, 4.VI.1963, 740m, leg. Wang Shuyong” (IZAS), 1 ♂ “Qiaoting, Wan County, Sichuan, 27.VI.1974, 1800m, leg. Han Yinheng” (IZAS), 1 ♂ “Mts. Shengtangshan, Jinxiu, Guangxi, 18.V.1999, leg. Yang Xingke” (IZAS), 2 ♂♂ “Mts. Tianpingshan, Longsheng, Guangxi, 5.VI.1963, leg. Shi Yongshan” (IZAS).

1 ♂ “Menghun, Xishuangbanna, Yunnan, 1200–1400 m, 22.5.1958, Zhang Yiran leg.” (IZAS), 1 ♀ “Menghun, Xishuangbanna, Yunnan, 1200–1400 m, 22.5.1958, Zhang Yiran leg.” (IZAS), 1 ♂ “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) ~20°12'N, 104°01'E; 1300–1900m; 01.–31.V.2011; leg. C. Holzschuh Ankauf ZFMK Bonn 2011” (ZFMK), 2 ♂♂, 3 ♀♀ “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) - 20°12'N, 104°01'E; 14.iv.–15.v.2012; 1300–1900m; leg. C. Holzschuh Ankauf ZFMK Bonn 2012/13” (ZFMK), 1 ♀ “Phu Rua N.P. (900m alt.) Loei P. NE Thai. 26–30.IV.2006 Takakuwa, M. leg.” (ZFMK), 1 ♂, 6 ♀♀ “Laos-NE, Houa Phan prov., 20°13'09–19''N, 103°59'54''-104°00'03''E, 1480–1510m Phou Pane Mt., 22.IV.–14.V.2008 Vit Kuban leg. (NMPC, ZFMK), 1 ♀ “Laos-NE Hua Phan prov., 20°12'N, 104°01'E, Phu Phan Mt., 1500–1900m, 17.5.–3.6.2007, leg. Vit Kuban” (ZFMK).

1 ♂ “Aotou, Huangkeng, Jianyang, Fujian, 5.V.1960, 800–950m, leg. Pu Fuji” (IZAS).

2 ♂♂ “Laos-NE, Houa Phan prov., 20°13'09–19''N, 103°59'54''-104°00'03''E, 1480–1510m Phou Pane Mt., 22.IV.–14.V.2008 Vit Kuban leg. (NMPC, ZFMK), 175 ex. “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) - 20°12'N, 104°01'E; 14.iv.–15.v.2012; 1300–1900m; leg. C. Holzschuh Ankauf ZFMK Bonn 2012/13” (ZFMK), 7 ex. “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) ~20°12'N, 104°01'E; 1300–1900m; 01.-31.V.2011; leg. C. Holzschuh Ankauf ZFMK Bonn 2011” (ZFMK), 39 ex. “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) - 20°12'N, 104°01'E; 11.iv.-15.v.2012; 1300–1900m; leg. C. Holzschuh Ankauf ZFMK Bonn 2012” (ZFMK), 1 ex. “Laos-NE Hua Phan prov., 20°12'N, 104°01'E, Phu Phan Mt., 1500–1900m, 17.5.–3.6.2007, leg. C. Holzschuh” (ZFMK), 2 ex. “Laos-NE, Houa Phan prov., 20°13'09–19''N, 103°59'54''-104°00'03''E, 1480–1510m Phou Pane Mt., 22.IV.–14.V.2008 Vit Kubáň leg. (NMPC, ZFMK).

2 ♂♂ “Longmenhe River, Xingshan, Hubei, 1300m, 10.5.1994, Zhang Youwei leg.” (IZAS), 1 ♂ “Xinmaopeng, Mt. Tianmu Shan, Zhejiang, 1300m, 28.6.1957, collector unknown” (IZAS), 1 ♂ “Qingyin’ge, Mt. Emei Shan, Sichuan, 800–1000m, 28.5. 1957, Wang Zongyuan leg.” (IZAS).

1 ♂ “Qiaoting, Wan County, Sichuan, 27.VI.1974, 1300m, leg. Han Yinheng” (IZAS), 1 ♂, 1 ♀ “Ku-ling, 7, 11.VII.1935, leg. O. Piel, Musee Heude” (IZAS), 1 ♂ “Mts. Tienmushan, 11.VI.1936, leg. O. Piel, Musee Heude” (IZAS).

1 ♂ “[China] Yunnan, Mt. Fofangshan, 2010-7-27, 22.59306N, 99.99068E, 1680m/ LW-1313” (IZAS).

This species was originally described from northern Vietnam; this is the first record for China.

1 ♂ “Mts. Qingchengshan, Sichuan, 2.VII.1979, 3100m, leg. Shang Jinwen” (IZAS), 1 ♂ “Tianshidong, Mts. Qingchengshan, Sichuan, 5.VI.1979, 1000m, leg. Gao Ping” (IZAS), 1 ♂ “Qinghe Forestry Farm, Kang County, Gansu, 8.VII.1999, 1400m, leg. Yao Jian” (IZAS), 1 ♂ “Jinzhong Road, Jinxiu, Guangxi, 12.V.1999, 1000m, leg. Gao Mingyuan” (IZAS), 1 ♂ “Baoguosi Temple, Mts. Emeishan, Sichuan, 11.V.1957, 550–750m, leg. Lu Youcai” (IZAS), 1 ♀ “Baoguosi Temple, Mts. Emeishan, Sichuan, 15.VI.1957, 800–1000m, leg. Huang Keren” (IZAS).

1 ♂ “Mts. Jiulianshan, Jiangxi, 21.VI.1975, Zhang Youwei leg.” (IZAS), 1 ♂ “Mt. Jianfengling, Hainan, 800–1000m, 19.V.1997, leg. Yu Peiyu” (IZAS), 1 ♂ “Shiping, Fengdu, Sichuan, 610m, 2.VI.1994, Zhang Youwei leg.” (IZAS), 1 ♂ “Mts. Tianpingshan, Longsheng, Guangxi, 4.VI.1963, 740m, leg. Shi Yongshan” (IZAS), 1 ♂ “Muyuping, Shennongjia, Hubei, 4.VII.1981, 1200m, leg. Han Yinheng” (IZAS), 6 ex. “China: Fujian Province; Mt. Liang-shan-ding, Wuping County, July 2–12, 2009 local collectors Ankauf via Li Jingke 2010” (ZFMK), 33 ex. “Laos-NE, Houa Phan prov., 20°13'09–19''N, 103°59'54''-104°00'03''E, 1480–1510m Phou Pane Mt., 22.IV.–14.V.2008 Vit Kubáň leg.” (NMPC, ZFMK), 217 ex. “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) - 20°12'N, 104°01'E; 14.iv.–15.v.2012; 1300–1900m; leg. C. Holzschuh Ankauf ZFMK Bonn 2012/13” (ZFMK), 48 ex. “NE-Laos: Hua Phan prov., Ban Saleui, Phou Pan (Mt.) - 20°12'N, 104°01'E; 11.iv.-15.v.2012; 1300–1900m; leg. C. Holzschuh Ankauf ZFMK Bonn 2012” (ZFMK), 6 ex. “Laos-NE Hua Phan prov., 20°12'N, 104°01'E, Phu Phan Mt., 1500–1900m, 17.5.–3.6.2007, leg. C. Holzschuh” (ZFMK), 9 ex. “Laos-NE Hua Phan prov., 20°12'N, 104°01'E, Phu Phan Mt., 1500–1900m, 17.5.–3.6.2007, leg. Vit Kuban” (ZFMK), 1 ♂ “Myanmar, Mandalay prov., Kyaukpadanng, 10.6.2009 From Li Jingke” (ZFMK).

1 ♂ “Sangang, Chonganxingcun, Fujian, 17.V.1960, 740–900m, leg. Ma Chenglin” (IZAS), 1 ♂ “Luoxiang, Jinxiu, Guangxi, 1.VII.2000, 450m, leg. Chen Jun” (IZAS), 1 ♂, 2 ♀♀ “Mts. Zuohushan, Longsheng, Guangxi, 23.VI.1982, leg. Yang Jikun”(CAU).

2 ex. “China, Fujian c., 21.-22.VI. Ziyungdongshan, NW slopes 25°46'N, 117°20'E, 900–1100m Jaroslav Turna leg., 2007” (CA).

1 ♂ “Cangyuan County, Yunnan, 16.V.1980, 990m, leg. Shang Jinwen” (IZAS).

First record for China.

1 ♂ “Qingyin Ge, Mts. Emeishan, Sichuan, 11.VI.1957, 800–1000m, leg. Lu Youcai” (IZAS), 1 ♂ “Qingyinge, Mts. Emeishan, Sichuan, 25.VI.1957, 800–1000m, leg. Huang Keren” (IZAS).

1 ♂ ”Huawangshanzhuang, Jinxiu, Guangxi, 900m, 20.V.1999, Zhang Yanzhou leg.” (IZAS), 1 ♂ ”Tonkin, Mont Bavi, 900–1000m, VIII.1940, leg. P.A. de Cooman” (IZAS), 1 ♂”Mengzhe, Xishuangbanna, Yunnan, 1200m, 15.VI.1958, Pu Fuji leg.” (IZAS), 1 ♂ “Tianchi, Jianfeng, Hainan, 11.IV.1980, 900m” (IZAS).

The specimens examined here, except the one from Tonkin, diverge somewhat from the holotype of Gastroserica yingi in the shape of the right paramere. However, it cannot be determined if this is due to local variation, or if there is some as yet unrecognized geographical pattern.

1 ♂ “Caiyang River Nature Preserve, Pu’er, Yunnan, 28–29.8.2007, Shi Lei leg.” (LSSYU).