Maladera nabanensis 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 : 337-339

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

Figures 81 A–D, 129

Type material examined. Holotype: ♂ “ China , S-Yunnan Prov. Xishuangbanna 23km NW Jinghong Na Ban village 680m 22°10.04’N 100°39.52’E, 20.V.2008, leg. A. Weigel, LF/ 785 Sericini Asia spec.” ( NME) . Paratypes: China: 1 ♂ “[China] Hetouzhai, Jinping , Yunnan, 12.V.1956, 1600-1700m, leg. Huang Keren etc.” ( IZAS) . Laos: 1 ♂ “ Laos north, 13.-24.V.1997 15 km NW Louang Namtha N21°07.5, E101°21.0 alt. 750+ 100m E. Jendek & O. Šauša leg./ 367 Sericini Asia spec.” ( ZFMK) .

Description. Length: 5.4 mm, length of elytra: 3.6 mm, width: 3.1 mm. Body oblong-oval, dark brown, antenna yellowish, dorsal surface shiny, dorsal face shortly densely setose.

Labroclypeus narrow and subtrapezoidal, little wider than long, widest at base, lateral margins weakly convex and convergent to strongly rounded anterior angles, lateral margin and ocular canthus producing a blunt angle; margins weakly reflexed; anterior margin weakly convex medially; surface moderately convex, shiny, finely and moderately densely punctate, glabrous; frontoclypeal suture weakly impressed and curved medially; smooth area in front of eye approximately three times as wide as long; ocular canthus long and narrow, finely punctate and with minute setae, without terminal seta. Frons with fine, very dense punctures, glabrous except for minute setae in punctures. Eyes extremely large, ratio of diameter/interocular width: 1.12. Antenna with ten antennomeres; club with three antennomeres, twice as long as remaining antennomeres combined, reflexed. Mentum anteriorly elevated and flattened.

Pronotum subrectangular, widest at base, lateral margins weakly convex and weakly convergent anteriorly; anterior angles produced and sharp, posterior angles blunt; anterior margin weakly convexly produced medially, marginal line complete; surface finely and densely punctate, with short dense setae; anterior and lateral margins glabrous. Scutellum wide, triangular, with fine and dense punctures, and short dense setae.

Elytra oblong, widest at middle, striae weakly impressed, finely and densely punctate, intervals flat, with fine, dense punctures and dense short setae; epipleural margin fine, ending at convex external apical angle of elytra, epipleura densely setose; apical border membraneous, with a rim of short microtrichomes.

Ventral surface with fine, dense punctures, densely shortly setose; metacoxa also shortly setose including several longer lateral setae. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/2.0. Abdominal sternites, in addition to fine and dense punctures with minute setae, each sternite with a distinct transverse row of coarse punctures each bearing a short and robust seta; penultimate sternite apically with a shiny smooth chitinous border, which is one quarter as long as sternite. Pygidium weakly convex, finely and densely punctate, without smooth midline; with dense short setae as in the rest of surface.

Legs short and wide; femora with two longitudinal rows of setae, finely and densely punctate, densely shortly setose; metafemur dull, anterior margin acute, with complete adjacent serrated line, posterior ventral margin widened in apical half, smooth, not serrate, dorsal posterior margin not serrated, finely setose. Metatibia wide and short, widest at apex, ratio width/length: 1/2.6, dorsal margin sharply carinate, with a continuously serrated line over its entire length; with two groups of spines, basal one at middle, apical one at three quarters of metatibial length; in basal half with a few robust single setae; lateral face weakly convex, with dense and fine punctures, and short setae in punctures; ventral margin serrate, with five equidistant robust and very long spines; medial face finely impunctate and glabrous; apex interiorly near tarsal articulation shallowly concave. Tarsomeres very sparsely punctate and setose dorsally, with dense, short setae ventrally; metatarsomeres ventrally with a strongly serrated ridge, beside which is a fine carina; first metatarsomere a little shorter than two following tarsomeres combined and slightly longer than dorsal tibial spur. Protibia short, bidentate. All claws symmetrical, feebly curved and long, with normally developed basal tooth.

Aedeagus: Fig. 81 A–C. Habitus: Fig. 81D . Female unknown.

Diagnosis. This new species differs from all other Chinese Maladera species in having extremely large eyes, short dense dorsal pilosity, and a serrated line along the entire length of the metatibia.

Etymology. The new species is named after its type locality, Na Ban village (adjective in the nominative singular).

Variation. Length: 5.4–6.0 mm, length of elytra: 3.6–4.0 mm, width: 2.8–3.1 mm.

Distribution. See map ( Fig. 129 ) and Table 1.

Figures

FIGURE 81. A–D: Maladera nabanensis Ahrens, Fabrizi & Liu, sp. n. (holotype); E–H: M. luoxiangensis Ahrens, Fabrizi & Liu, sp. n. (holotype). A: aedeagus, left side lateral view; C, G: aedeagus, right side lateral view; B, E: parameres, dorsal view; F: aedeagus, ventral view; D, H: habitus. Scale: 0.5 mm. Habitus not to scale.

FIGURE 129. Distribution of Maladera species with uncertain systematic status: Maladera baishaoensis sp. n., M. hutiaoensis sp. n., M. jinggangshanica sp. n., M. lukjanovitschi (Medvedev, 1966), M. luoxiangensis sp. n., M. nabanensis sp. n., M. nanlingensis sp. n..