Gastroserica liboensis 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 : 97-99

Taxon classification Animalia Coleoptera Scarabaeidae

Gastroserica liboensis Liu & Ahrens sp. n. Figs 2 E–H, 4

Type material examined.

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

Description.

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 ir regularly 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.

Aedeagus.

Fig. 2 E–G.

Diagnosis.

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.

Etymology.

Named after the type locality, Libo.

Variation.

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.