Maladera yakouensis 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 : 120-121

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

Figures 25 I–L, 98

Type material examined. Holotype: ♂ “[ China] Yunnan, Yakou , 2012-V-11 / LW-1289” ( ISAZ).

Description. Length: 8.1 mm, length of elytra: 6.8 mm, width: 5.8 mm. Body oblong-oval, dark brown, antenna yellow, shiny iridescent, dorsal face nearly glabrous.

Labroclypeus wide and subtrapezoidal, widest at base, lateral margins weakly convex and convergent anteriorly, anterior angles moderately rounded, anterior margin distinctly emarginate, margins weakly reflexed; lateral margin and ocular canthus produce an indistinct angle; surface weakly convex medially, finely, densely punctate, with a few long setae anteriorly; frontoclypeal suture finely incised, weakly curved; smooth area anterior to eye convex, 1.5 times as wide as long; ocular canthus short and wide (1/4 of ocular diameter), finely densely punctate, with one terminal seta. Frons with dense and fine punctures, with a few fine setae beside eyes. Eyes small, ratio diameter/ interocular width: 0.58. Antenna with ten antennomeres; club with three antennomeres and straight, as long as remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum transverse, widest at base, lateral margins evenly convex and weakly convergent anteriorly, anterior angles distinctly produced and sharp, posterior angles moderately rounded; anterior margin convex, with fine complete marginal line, base without marginal line; surface finely and densely punctate, with minute setae in punctures being as long as puncture diameter, otherwise glabrous, with a shallow median longitudinal impression; lateral margins sparsely setose; hypomeron carinate, not produced ventrally. Scutellum wide, triangular, with fine, dense punctures, impunctate medially.

Elytra widest in posterior third, striae finely impressed, finely and densely punctate, intervals weakly convex, with fine, moderately dense punctures, with minute setae in punctures, penultimate lateral interval with a few fine setae; epipleural margin robust, ending at apical external angle of elytra, epipleura densely setose; apical border of elytra membraneous, with a very fine rim of microtrichomes (visible at ca 100x magnification).

Ventral surface dull, coarsely and densely punctate, metasternum including disc densely setose; metacoxa glabrous, with a few longer setae laterally. Abdominal sternites finely and densely punctate, punctures with minute setae, 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: 1/1.4. Pygidium dull, strongly convex, finely and densely punctate, with short smooth midline, with numerous long and short, fine setae in apical half.

Legs moderately long and narrow, shiny; femora with two longitudinal rows of setae, coarsely and moderately densely punctate. Anterior margin of metafemur acute, with adjacent continuous serrated line, anterior row of setae complete; posterior ventral margin smooth, weakly widened at ventral apex, dorsal posterior margin smooth, neither serrate, glabrous. Metatibia long and wide, widest at apex, ratio of width/length: 1/3.6, moderately carinate dorsally, with two groups of spines, basal group at three fifths, apical group at four fifths of metatibial length, in basal half with a few short and fine single setae and a continuous serrated line beside entire dorsal margin until the basal group of spines; lateral face longitudinally convex, with sparse fine punctures in basal half, minutely setose; ventral margin finely serrate, with three 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 with a strongly serrated ridge ventrally and a smooth subventral longitudinal carina; first metatarsomere distinctly longer than following tarsomere and slightly longer than dorsal tibial spur. Protibia moderately long, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Fig. 25 I–K. Habitus: Fig. 25L . Female unknown.

Diagnosis. Maladera yakouensis Ahrens, Fabrizi & Liu , sp. n. differs from all other large species of the M. egregia group in that the fused left and right parameres have two pronounced, pointed tips.

Etymology. The name (adjective in the nominative singular case) of the new species is derived from its type locality, Yakou.

Distribution. See map ( Fig. 98 ) and Table 1.

Figures

FIGURE 25.A–D: Maladera diaolinensis Ahrens, Fabrizi & Liu, sp. n. (holotype); E–H: M. yipinglangensis Ahrens, Fabrizi & Liu, sp. n. (holotype); I–L: M. yakouensis 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 98. Distribution of the Maladera egregia group: Maladera pseudoegregia sp. n., M. tiachiensis sp. n., M. tiani sp. n., M. yakouensis sp. n., M. yipinglangensis sp. n..