Maladera rubriventris 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 : 246-247

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

Figures 57 E–H, 119

Type material examined. Holotype: ♂ “X-DA2985 China S. Yunnan (Xishuangbanna) 23km NW Jinghong vic. Na Ban ( NNNR), 730m 22°09.49’N, 100°39.92’E 20.x.2008 L. Meng Maladera spCHz 2 ♂ / 802 Sericini Asia spec.” ( ZFMK) . Paratype: 1 ♂ “[ China] Meng’e, Xishuangbanna , Yunnan, 16.VIII.1958, 1050- 1080m, leg. Pu Fuji ” ( IZAS) .

Description. Length: 11.3 mm, length of elytra: 8.1 mm, width: 6.0 mm. Body elongate, dark reddish brown, antenna yellow, dorsal surface dull, except a few small setae on head and elytra glabrous.

Labroclypeus 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 moderately reflexed, anteriorly very shallowly emarginate medially; surface flat, shiny, coarsely and densely punctate, with a transverse row of long, erect setae anteriorly; frontoclypeal suture feebly impressed and moderately angled medially; smooth area in front of eye approximately 1.5 times as wide as long; ocular canthus short and wide, finely punctate, with one terminal seta. Frons dull, with fine, moderately dense punctures, with long setae beside eyes. Eyes small, ratio of diameter/interocular width: 0.51. Antenna with 10 antennomeres; club with three antennomeres, 1.2 times as long as remaining antennomeres combined. Mentum anteriorly elevated and flattened.

Pronotum subtrapezoidal, widest at base, lateral margins convex and evenly convergent anteriorly, anterior angles moderately produced and sharp, posterior angles rounded; anterior margin weakly convex, marginal line complete; surface moderately finely and densely punctate, with minute setae in punctures; anterior and lateral margins sparsely setose; hypomeron carinate. Scutellum wide, triangular, with fine and moderately dense punctures each bearing a single minute seta, punctures along middle less dense.

Elytra oval, widest at middle, striae distinctly impressed, finely and densely punctate, intervals almost flat, with fine, dense punctures concentrated along striae, punctures with minute setae; epipleural margin robust, ending at the strongly rounded external apical angle of elytra, epipleura sparsely setose, apical border membraneous, with a fine rim of very short microtrichomes.

Ventral surface dull, metasternum and metacoxa with large and dense punctures, meso-and metasternum densely setose; metacoxa with minute setae and several long setae laterally. Abdominal sternites in addition to generally distributed fine and moderately dense punctures each with a distinct transverse row of coarse punctures each bearing a short and robust seta, otherwise punctures each with a microscopic seta. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.92. Pygidium moderately convex, finely and moderately densely punctate, without smooth midline, punctures with microscopic setae, with a few short and long setae along apical margin.

Legs short and wide; femora with two longitudinal rows of setae, finely and sparsely punctate. Metafemur dull, anterior margin acute, lacking an adjacent serrated line and anterior longitudinal row of setae, posterior ventral margin medially straight, strongly widened in apical half and not serrate, dorsally not serrated, finely setose. Metatibia short and wide, widest at middle, ratio width/length: 1/2.2, dorsally sharply carinate, with two groups of spines, basal one at middle, apical one at three quarters of metatibial length, without contiguous serrated line basally; lateral face longitudinally convex, with a few large superficial punctures on base; ventral margin finely serrate, with five equidistant spines; medial face impunctate; apex interiorly near tarsal articulation shallowly concave. Tarsomeres impunctate dorsally, ventrally with sparse, short setae; metatarsomeres ventrally glabrous, with a strongly serrated ridge, beside with subventral longitudinal carina; first metatarsomere shorter than following two 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. 57 E–G. Habitus: Fig. 57H . Female unknown.

Diagnosis. In general habitus and shape of the aedeagus, Maladera rubriventris Ahrens, Fabrizi & Liu , sp. n. is very similar to M. bubengensis Ahrens, Fabrizi & Liu , sp. n.. The new species differs from the latter in having the basal lobe of parameres more pronounced, the parameres are more angulate ventrally and slightly reflexed apically.

Etymology. The name of the new species is derived from the combined Latin words rubis (red) and venter (belley, ventral side), with reference on the reddish color of the ventral surface of the species (adjective in the nominative singular case).

Variation. Length: 9.0– 11.3 mm, length of elytra: 7.1–8.1 mm, width: 5.4–6.0 mm.

Distribution. See map ( Fig. 119 ) and Table 1.

Figures

FIGURE 57. A–D: Maladera bubengensis Ahrens, Fabrizi & Liu, sp. n. (holotype); E–H: M. rubriventris Ahrens, Fabrizi & Liu, sp. n. (holotype); I–L: M. wulaoshanicaAhrens, Fabrizi & Liu, sp. n. (holotype). A, E, I: aedeagus, left side lateral view; C, G, K: aedeagus, right side lateral view; B, F, J: parameres, dorsal view; D, H, L: habitus. Scale: 0.5 mm. Habitus not to scale.

FIGURE 119. Distribution of the Maladera ferruginea group: Maladera rubriventris sp. n., M. taiyangheensis sp. n., M. tengchongensis sp. n., M. tongzhongensis sp. n., M. wulaoshanica sp. n..