Gastroserica carolusi Liu & Ahrens

Liu, Wan-Gang, Bai, Ming, Yang, Xing-Ke & Ahrens, Dirk, 2014, An update to the taxonomy of the genus Gastroserica Brenske (Coleoptera, Scarabaeidae, Sericini), ZooKeys 426, pp. 87-110 : 90-92

Taxon classification Animalia Coleoptera Scarabaeidae

Gastroserica carolusi Liu & Ahrens sp. n. Figs 1 A–D, 4

Material examined.

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).

Description.

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 meso coxae 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.

Aedeagus.

Fig. 1 A–C.

Diagnosis.

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.

Etymology.

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.

Variation.

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.

Remarks.

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.