Maladera excisilabrata 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 : 259-260

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

Figures 60 I–L, 121

Type material examined. Holotype: ♂ “[ China] Mt. Lushan , Jiangxi, 10.V.1977, leg. Zhang Youwei ” ( IZAS).

Description. Length: 9.0 mm, length of elytra: 6.6 mm, width: 5.4 mm. Body oval, reddish brown, antenna brown, head and pronotum weakly shiny, remainder of dorsal surface dull, glabrous.

Labroclypeus subtrapezoidal, little wider than long, widest at base, lateral margins weakly convex and strongly convergent to moderately rounded anterior angles, lateral margin and ocular canthus producing a blunt angle, margins moderately reflexed, anterior margin weakly emarginate medially; surface transversely convex medially, shiny, coarsely and moderately densely punctate, distance between punctures equal their diameter, with few long, erect setae anteriorly; frontoclypeal suture weakly impressed and angled medially; smooth area in front of eye approximately three times as wide as long; ocular canthus short and wide, finely punctate, without terminal seta. Frons with fine, dense punctures, glabrous except for a few setae beside eyes. Eyes small, ratio of diameter/interocular width: 0.53. Antenna with 10 antennomeres; club with three antennomeres, slightly longer than remaining antennomeres combined. Mentum anteriorly elevated and flattened.

Pronotum subtrapezoidal, widest at base, lateral margins weakly convergent anteriorly, anterior angles moderately produced but sharp, anterior margin weakly convex, marginal line widely interrupted medially; surface finely and densely punctate, glabrous; anterior and lateral margins sparsely setose; hypomeron carinate. Scutellum wide, triangular, with fine and dense punctures, each bearing a single minute seta.

Elytra oblong, widest at middle, striae weakly impressed, finely and densely punctate, intervals weakly elevated, with fine, moderately dense punctures concentrated along striae, odd intervals with a few fine, erect, short setae, otherwise punctures with a very minute seta; epipleural margin robust, ending at strongly rounded external apical angle of elytra, epipleura sparsely setose, apical border membraneous, with a rim of very short microtrichomes.

Ventral surface dull, metasternum and metacoxa with large and dense punctures, sparsely setose; metacoxa glabrous except for a 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, punctures with microscopic setae, penultimate sternite apically with a shiny smooth short chitinous border. Mesosternum between mesocoxae narrower than mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.43. Pygidium of holotype lost after dissection.

Legs moderately long and wide; femora with two longitudinal rows of setae, finely and moderately densely punctate; metafemur dull, anterior margin acute, lacking an adjacent serrated line, posterior ventral margin medially straight, weakly widened in apical half and entirely strongly serrate, dorsally also serrate, finely setose. Metatibia moderately wide and long, widest at apex, ratio width/length: 1/3.3, dorsally sharply carinate, with two groups of spines, basal one at middle, apical one at four fifths of metatibial length, in basal half with a blunt subdorsal margin, beside it with a few punctures, and short spines; lateral face longitudinally convex, with moderately dense and fine punctures, punctures with minute setae; ventral margin serrate, with two widely distant spines; medial face finely sparsely punctate, apex interiorly near tarsal articulation shallowly concave. Tarsomeres impunctate dorsally, ventrally with sparse, short setae; metatarsomeres ventrally glabrous, with a strongly serrated ridge, and a subventral longitudinal carina beside it; 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. 60 I–K. Habitus: Fig. 60L . Female unknown.

Diagnosis. Maladera excisilabrata Ahrens, Fabrizi & Liu , sp. n. differs from all other Chinese Maladera in having narrow lateral apophyses on the apex of the phallobase as well as having short, ventrally curved parameres. Additionally, it differs from M. uncipenis in having impunctate tarsomeres.

Etymology. The name of the new species is derived from the combined Latin adjectives ‘excisus-’ (emarginate) and ‘labratus’ (with labrum), with reference to the deeply excavated labrum (adjective in nominative singular case).

Distribution. See map ( Fig. 121 ) and Table 1.

Figures

FIGURE 60. A–D: Maladera tiammushanicaAhrens, Fabrizi & Liu, sp. n. (holotype); E–H: M. putaodiensis Ahrens, Fabrizi & Liu, sp. n. (holotype); I–L: M. excisilabrata 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 121. Distribution of the Maladera uncipenis group: Maladera baii sp. n., M. bawanglingana sp. n., M. beidouensis sp. n., M. chinensis (Moser, 1915), M. dadongshanica sp. n., M. dayaoshanica sp. n., M. emeifengensis sp. n., M. excisilabrata sp. n..