Maladera yibini 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 : 82-83

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

Figures 17 A–D, 94

Type material examined. Holotype: ♂ “ Miao Village, Baisha , Hainan, 4-5.VI.2007, leg. Ba Yibin, Lang Juntong/ LW-772” ( HBUM) . Paratype: 1 ♂ “ Shuiman, Mts. Wuzhishan , Hainan, 23-25. V.2007, leg. Ba Yibin, Lang Juntong” ( ZFMK) .

Description. Length: 11.0 mm, length of elytra: 8.2 mm, width: 6.6 mm. Body oblong-oval, dark brown, antenna yellowish, surface dull, labroclypeus shiny, except a few short setae on sides of elytra, glabrous.

Labroclypeus wide and subtrapezoidal, widest at base, lateral margins weakly convex and convergent anteriorly, anterior angles widely rounded, anterior margin weakly emarginate medially; margins moderately reflexed; lateral margin and ocular canthus produce an indistinct angle; surface flat, with an indistinct longitudinal elevation behind anterior margin, finely, densely punctate, glabrous; frontoclypeal suture distinctly incised, angled medially; smooth area anterior to eye convex, four times as wide as long; ocular canthus short and narrow (1/3 of ocular diameter), finely densely punctate, terminal seta lacking. Frons dull, with moderately dense, fine punctures, with a few single setae beside eyes. Eyes large, ratio diameter/ interocular width: 0.73. Antenna with ten antennomeres; club with three antennomeres and straight, 1.1 times as long as remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum transverse, widest at base, lateral moderately evenly convex and convergent anteriorly, anterior angles distinctly produced and sharp, posterior angles moderately rounded; anterior margin weakly convex, with fine complete marginal line, base without marginal line; surface moderately finely and densely punctate, with minute setae in punctures; anterior and lateral margin finely setose; hypomeron carinate, not produced ventrally. Scutellum wide, triangular, with fine, moderately dense punctures.

Elytra widest at middle, striae finely impressed, finely and densely punctate, intervals slightly convex, with fine, moderately dense punctures, with minute setae in punctures, otherwise glabrous; epipleural margin robust, ending at nearly blunt external apical angle of elytra, epipleura sparsely setose; apical border of elytra membraneous, with a fine rim of microtrichomes (visible at ca 100x magnification).

Ventral surface dull, finely and densely punctate, with dense and fine, adpressed setae, metasternal disc sparsely covered with longer setae; metacoxa with a few longer setae laterally. Abdominal sternites finely and densely punctate, glabrous, each sternite with a transverse row of punctures each bearing a fine seta. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.74. Pygidium weakly convex, dull, finely and sparsely punctate, without smooth midline, with a few long setae along apical margin.

Legs short and wide; femora dull, with two longitudinal rows of setae, finely and sparsely punctate. Anterior margin of metafemur acute, without adjacent serrated line, anterior row of setae completely reduced; posterior ventral margin smooth, moderately widened at ventral apex, dorsal posterior margin smooth, neither serrate, glabrous. Metatibia short and wide, widest at middle, ratio of width/length: 1/2.7, sharply carinate dorsally, with two groups of spines, basal group at middle, apical group at three quarters of metatibial length, in basal half with a few short single spines close to dorsal margin; lateral face longitudinally convex, nearly entirely impunctate, only a few fine punctures beside dorsal and ventral margin, glabrous; ventral margin finely serrate, with four equidistant robust setae; medial face smooth and glabrous; apex finely serrate, shallowly emarginate interiorly near tarsal articulation. Tarsomeres dorsally impunctate, glabrous, neither laterally nor dorsally carinate, moderately setose ventrally; metatarsomeres lacking in holotype. Protibia moderately long, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Fig. 17 A–C. Habitus: Fig. 17D . Female unknown.

Diagnosis. Maladera yibini Ahrens, Fabrizi & Liu , sp. n. differs from all other dark brown Omaladera species with long tubular phallobase in having the right and left parameres straight, with the right paramere sharply pointed.

Etymology. Maladera yibini Ahrens, Fabrizi & Liu , sp. n. is named after one of its collectors, Ba Yibin (noun in the genitive singular case).

Variation. Length: 10.5–11.0 mm, length of elytra: 8.2–8.3 mm, width: 6.6–6.7 mm.

Distribution. See map ( Fig. 94 ) and Table 1.

Figures

FIGURE 17.A–D: Maladera yibini Ahrens, Fabrizi & Liu, sp. n. (holotype); E–H: M. wuliangshanensis Ahrens, Fabrizi & Liu, sp. n. (holotype); I–L: M. businskyorum Ahrens, 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 94. Distribution of the subgenus Omaladera: Maladera sontica (Brenske, 1898), M. verticalis (Fairmaire, 1888), M. weni sp. n., M. wuliangshanensis sp. n., M. xingkei sp. n., M. yibini sp. n..