Maladera bikouensis Ahrens, Fabrizi & Liu, 2021

Fabrizi, Silvia, Liu, Wan-Gang, Bai, Ming, Yang, Xing-Ke & Ahrens, Dirk, 2021, A monograph of the genus Maladera Mulsant & Rey, 1871 of China (Coleoptera: Scarabaeidae: Melolonthinae: Sericini), Zootaxa 4922 (1), pp. 1-400 : 230-232

Maladera bikouensis Ahrens, Fabrizi & Liu , sp. n.

Figures 53 A–E, 117

Type material examined. Holotype: ♂ “[ China] Bikou , Wen County, Gansu, 27.VII. 1999, 720m, leg. Zhu Chaodong” ( IZAS) . Paratypes: 1 ♂ “[ China] Shiping, Fengdu , Sichuan, 3.VI. 1994, 610m, leg. Zhang Youwei ” ( IZAS) , 1 ♂ “[ China] Guanyin’ge, Mts. Emeishan , Sichuan, 13.VI.1957, 800- 1000m, leg. Huang Keren ” ( ZFMK) .

Description. Length: 11.2 mm, length of elytra: 8.8 mm, width: 6.0 mm. Body wide, oval, dark brown, antenna yellowish brown, dorsal surface dull, labroclypeus, tarsomeres, and tibiae shiny, glabrous.

Labroclypeus wide, lateral margins weakly convex and moderately convergent, lateral margins produce with ocular canthus a blunt angle, anterior angles convex, anterior margin shallowly emarginate medially, margins weakly reflexed; surface moderately shiny, at base narrowly dull, surface weakly convex, finely and densely punctate, distance between punctures smaller their diameter, with numerous long erect setae; smooth area in front of eyes twice as wide as long; frontoclypeal suture finely incised, bluntly angled medially; ocular canthus moderately wide and short (1/3 of ocular diameter), finely and densely punctate, with two or three short terminal setae. Eyes moderately large, ratio diameter/ interocular width: 0.58. Frons with fine and moderately dense punctures, with a few single setae beside eyes and behind frontoclypeal suture. Antenna with ten antennomeres, club with three antennomeres and straight, as long as remaining antennomeres combined. Mentum convexly elevated and flattened anteriorly.

Pronotum widest shortly before base, lateral margins evenly convex and convergent anteriorly, and also posteriorly, anterior angles sharp and distinctly produced, posterior angles moderately rounded; anterior margin convex, with complete marginal line; basal margin without marginal line; surface finely and densely punctate, punctures with microscopic setae only, setae of lateral and anterior margin sparse; hypomeron carinate. Scutellum wide, triangular, punctation as in pronotum, impunctate on basal midline.

Elytra convex, widest at posterior third, striae finely impressed, finely punctate, intervals weakly convex, finely and densely punctate, punctures concentrated along striae, with minute setae in punctures, odd intervals with a few erect short setae; epipleura ending at strongly rounded external apical angle of elytra, sparsely setose; apex of elytra with a fine membraneous rim of short microtrichomes.

Ventral face coarsely and densely punctate, nearly glabrous, only metasternal plate and lateral metacoxa with a few robust setae. Distance between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.62. Abdominal sternites finely and moderately densely punctate, each with a row of coarse punctures bearing each a robust seta; penultimate sternite medially retracted, ultimate sternite 1.5 times as long as penultimate. Pygidium moderately convex, coarsely and densely punctate, on apex with a few long setae.

Legs moderately long and wide; femora superficially and sparsely punctate, with two longitudinal rows of setae. Metafemur shiny, anterior margin acute, without adjacent serrated line, anterior longitudinal row of setae present; posterior ventral margin almost straight, not widened in apical half, posterior margin ventrally in apical half and dorsally completely serrated, glabrous. Metatibia moderately long and wide, dorsal and ventral margin subparallel, ratio width/length: 1/3.45, sharply carinate dorsally, with two groups of spines, basal one at basal third, apical one at three quarters of metatibial length, basally with a few robust and short setae; lateral face weakly longitudinally convex, with coarse and moderately dense punctures; ventral margin with two widely separated spines; medial face impunctate, apex shallowly and concavely emarginate interiorly near tarsal articulation. Tarsomeres sparsely finely punctate dorsally, with dense, fine setae ventrally; metatarsomeres ventrally glabrous, with a strongly serrated carina, subventrally with a second, smooth longitudinal carina; first metatarsomere slightly shorter than following two tarsomeres combined, little longer than dorsal tibial spur. Protibia short, bidentate. Anterior claws symmetrical.

Aedeagus: Fig. 53 A–D. Habitus: Fig. 53E . Female unknown.

Diagnosis. Maladera bikouensis Ahrens, Fabrizi & Liu , sp. n. differs from M. liwenzhui Ahrens, Fabrizi & Liu , sp. n. in having slightly shorter parameres and the right paramere is lacking the blunt ventral tooth.

Etymology. The new species is named after the type locality, Bikou (adjective in the nominative singular).

Variation. Length: 11.1–11.2 mm, length of elytra: 8.0– 8.8 mm, width: 6.0– 6.2 mm.

Distribution. See map ( Fig. 117 ) and Table 1.

Figures

FIGURE 53. A–E: Maladera bikouensis Ahrens, Fabrizi & Liu, sp. n. (holotype); F–I: M. shiwandashanensis Ahrens, Fabrizi & Liu, sp. n. (holotype); J–M: M. wupingensis Ahrens, Fabrizi & Liu, sp. n. (holotype). A, F, J: aedeagus, left side lateral view; D, H, L: aedeagus, right side lateral view; B, C, G, K: parameres, dorsal view; E, I, M: habitus. Scale: 0.5 mm. Habitus not to scale.

FIGURE 117. Distribution of the Maladera liwenzhui group: Maladera bikouensis sp. n., M. liwenzhui sp. n., M. shiwandashanensis sp. n., M. wupingensis sp. n..