Maladera gusakovi 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 : 116-117

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

Figures 24 J–M, 97

Type material examined. Holotype: ♂ “ China: Hunan; Mupu Mt. 1600m, Pingjiang VIII-2003, leg. Li et al. / 873 Sericini : Asia spec.” ( ZFMK) . Paratypes: 2 ♀♀ “ China: Hunan; Mupu Mt. 1600m, Pingjiang VIII-2003, leg. Li et al. / 873 Sericini : Asia spec.” ( ZFMK) .

Description. Length: 9.1 mm, length of elytra: 6.4 mm, width: 5.3 mm. Body oval, dark brown, antenna yellow, dull, labroclypeus and elytra shiny, dorsal face nearly glabrous.

Labroclypeus wide and subtrapezoidal, widest at base, lateral margins straight and convergent anteriorly, anterior angles strongly rounded, anterior margin distinctly emarginate, margins weakly reflexed; lateral margin and ocular canthus produce an indistinct angle; surface weakly convex, 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 dull, with sparse and fine punctures, with a few fine setae beside eyes. Eyes small, ratio diameter/ interocular width: 0.67. Antenna with ten antennomeres; club with three antennomeres and straight, slightly longer than remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum transverse, widest at base, lateral margins evenly convex and weakly convergent anteriorly, anterior angles moderately produced and right-angled, posterior angles blunt, slightly rounded at tip; anterior margin straight, with fine marginal line, base without marginal line; surface finely and densely punctate, with minute setae in punctures being as long as puncture diameter, otherwise glabrous; lateral margin densely setose; hypomeron carinate, not produced ventrally. Scutellum dull, wide, triangular, with fine, dense punctures.

Elytra widest inposterior third, striae finely impressed, finely and densely punctate, intervals weakly convex, with fine, moderately dense punctures concentrated along striae, 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 slightly concave before apex, 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: 1/1.22. Pygidium dull, weakly convex, finely and densely punctate, without 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 moderately wide, widest at apex, ratio of width/length: 1/3.3, 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, minutely setose; 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 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. 24 J–L. Habitus: Fig. 24M . Female unknown.

Diagnosis. Maladera gusakovi Ahrens, Fabrizi & Liu , sp. n. differs from all other iridescent species of the M. egregia group in having the dorsolateral apical process of the phallobase strongly reflexed and directed externally.

Etymology. The new species is named (noun in the genitive singular case) in honour of Aleksey Gusakov (Moscow), thanking for his support with the examination of some Motschulsky type specimens.

Variation. Length: 8.7–9.1 mm, length of elytra: 6.4–6.6 mm, width: 5.2–5.3 mm. Female: eyes little smaller than in male, ratio of diameter/interocular width: 0.58; antennal club with three antennomeres, as long as remaining antennomeres combined; pygidium flat, before apical margin strongly convex.

Distribution. See map ( Fig. 97 ) and Table 1.

Figures

FIGURE 24. A–E: Maladera laocaiensis Ahrens, Fabrizi & Liu, sp. n. (holotype); F–I: M. pseudoegregia Ahrens, Fabrizi & Liu, sp. n. (holotype); J–M: M. gusakovi Ahrens, Fabrizi & Liu, sp. n. (holotype). A, F, L: aedeagus, left side lateral view; D, H, L: aedeagus, right side lateral view; B, G, K: parameres, dorsal view; C: parameres, ventral view; E, I, M: habitus. Scale: 0.5 mm. Habitus not to scale.

FIGURE 97. Distribution of the Maladera egregia group: Maladera diaolinensis sp. n., M. egregia (Arrow, 1946), M. gusakovi sp. n., M. hmong Ahrens, 2004, M. hubeiensis sp. n., M. laocaiensis sp. n., M. levis (Frey, 1972).