Gastroserica nigrofasciata Liu, Ahrens, Bai & Yang

Liu, Wan-Gang, Ahrens, Dirk, Bai, Ming & Yang, Xing-Ke, 2011, A key to species of the genus Gastroserica Brenske of the China (Coleoptera, Scarabaeidae, Sericini), with the description of two new species and two new records for China, ZooKeys 139, pp. 23-44 : 27-30

Gastroserica nigrofasciata Liu, Ahrens, Bai & Yang sp. n.

Type material.

Holotype: 1♂"Mt. Tianping Shan, Longsheng, Guangxi, 740 m, 9.6.1963, Wang Shuyong leg." (IZAS). Paratypes (1♂+5♀♀): 1♂"Hongmaochong, Longsheng, Guangxi, 900 m, 10.6.1963, Shi Yongshan leg." (ZFMK); 1♀" Hongmaochong, Longsheng, Guangxi, 900 m, 10.6.1963, Shi Yongshan leg." (ZFMK); 1♀" Hongmaochong, Longsheng, Guangxi, 900 m, 10.6.1963, Wang Shuyong leg." (IZAS); 1♀"Mt. Tianping Shan, Longsheng, Guangxi, 740 m, 4.6.1963, Wang Shuyong leg." (IZAS); 1♀" Neicu River, Longsheng, Guangxi, 840 m, 7.6.1963, Wang Shuyong leg." (IZAS); 1♀"Mt. Fanjing Shan, Jiangkou, Guizhou, 530 m, 12.7.1988, Wang Shuyong leg." (IZAS).

Description.

Length: 5.6-8.0 mm, length of elytra: 4.1-5.1 mm, width: 3.2-4.1 mm. Body oval,elytra and dorsal surface both yellow, densely covered with short, fine adpressed setae and with moderately dense, long, erect setae interspersed (Fig. 1 H).

Labroclypeus subrectangular and short, widest at base, lateral margins straight and moderately divergent from anterior angles to base, anterior angles broadly rounded, lateral border and ocular canthus produced into a distinct obtuse angle, anterior margin weakly reflexed, straight, surface weakly convex medially and moderately shiny, very coarsely and sparsely punctate, with several long, erect setae; frontoclypeal suture distinctly impressed and strongly curved, smooth area in front of eye distinctly wider than long (1.8/1); ocular canthus moderately short and strong, finely and densely punctate. Frons with coarse, dense punctures, with fine punctures irregularly interspersed, densely erectly setose. Eyes moderately large, ratio of diameter/ interocular width: 0.63. Antenna brown, with ten antennomeres, club in male with four antennomeres, first joint of club slight shorter than the others, club slightly longer than the remaining antennomeres combined. Mentum elevated and flated anteriorly.

Pronotum rectangular, widest at half of length, lateral margins strongly convergent anteriorly, before posterior angles weakly sinuate, anterior angles not produced and strongly rounded, almost obsolete, posterior angles moderately blunt and weakly produced outward, anterior margin almost straight, with a distinct and fine marginal line, basal margin moderately curved without marginal line, and two weak impressions at quarter of width to the lateral margins; surface with moderately dense and fine punctures, with numerous minute setae, which are bentbackwards and two black spots at the middle, along the middle weakly medially impressed, with a weakly elevated transverse carina behind the middle; anterior and lateral borders setaceous; basal margin of hypomeron strongly produced ventrally, before base distinctly transversely sulcate. Scutellum nearly triangular, apex weakly rounded, with fine and dense punctures, medially smooth, minute setae present in the punctures.

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

Ventral surface dull, with large and dense punctures and dense short setae, setae adpressed, metacoxa partly glabrous, laterally with fine adpressed setae, each abdominal sternite with indistinct transversal row of coarse punctures bearing each a short strong seta between fine and dense punctation, all sternites with fine, short setae. Mesosternum between mesocoxae almost 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 and dense punctures bearing fine setae and a few robust punctures bearing each a robust seta, without smooth midline.

Legs pale yellow to yellow brown, 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, ventrally weakly widened in apical half but not serrate, dorsally serrate, with short setae. Metatibia moderately broad, at middle convexly widened, ratio width/ length: 1/ 3.2, dorsally sharply carinate, with two groups of spines, the basal group at one third, apical one at two third of metatibial length, basally with a few single spines in punctures; lateral face longitudinally convex, with dense and moderately coarse punctures, some of them longitudinally impressed, ventral edge serrated; medial face not punctate and smooth, apex interiorly near tarsal articulation sharply truncate. Tarsomeres dorsally glabrous and finely punctate, ventrally with sparse, short setae, metatarsomeres dorsally with strong longitudinal impressions, ventrally with a strongly serrated ridge, laterally with a strong longitudinal carina, first metatarsomere as long as the following two tarsomeres combined and twice as long as the upper tibia spur. Protibia short, bidentate, protarsal claws symmetrical.

Aedeagus.

Fig. 1 D–F.

Variation.

Smooth area in front of eye wider than long (the rate from 1.8/1 to 2.0/1). Eyes weakly large, ratio of diameter/ interocular width: (0.60-0.67). Club a little shorter than the remaining antennomeres combined in female. Elytra from yellow to brown, with greenish metallic shine. Three intervals next to the lateral margins of elytra sometimes black. Ratio of length of metepisternum/ metacoxa: (1/ 1.82-2.).

Diagnosis.

Gastroserica nigrofasciata sp. n. is in habitus very similar to Gastroserica marginalis (Brenske, 1897). It maybe differentiated from Gastroserica marginalis by the colour of elytra and dorsal surface, the presence of two long lateral apophyses at the apex of phallobasis, and the shape of parameres.

Derivatio nominis.

From the Latin words “nigro-” and “fasciata” meaning black stripes.

Distribution.

Fig. 5.