Maladera subtruncata ( Fairmaire, 1887 ) Fabrizi & Liu & Bai & Yang & Ahrens, 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 : 142-143

Maladera subtruncata ( Fairmaire, 1887) comb. n.

Figures 30 I–L, 103

Serica subtruncata Fairmaire, 1887: 109 ; Ahrens 2006b: 245; 2007b: 36.

Type material examined. Lectotype (here designated): 1 ♀ “ Yunnan / Serica subtruncata Fairm. / Museum Paris ex. coll. Oberth ̹r” ( MNHN).

Additional material examined. 1 ♂ “[ China] Yunnan, Nabanhe nature reserve , 2009-III-16 / LW-1214” ( ISAZ) . 1 ♂ “[ China] Yunnan, Nabanhe nature reserve , 2009-III-16 / LW-1214bis” ( ZFMK) , 1 ♂ “NW Thailand 9.-16.V. Mae Hong Son 1991 Ban Huai Po 1600m leg. P. Pacholátko / TS 127/ 275 Sericini Asia spec.” ( CP) .

Redescription. Length: 10.4 mm, length of elytra: 7.5 mm, width: 6.1 mm. Body oblong-oval, dark brown, dull, labroclypeus shiny, dorsal face nearly glabrous.

Labroclypeus moderately wide and subtrapezoidal, widest at base, lateral margins weakly convex and convergent anteriorly, anterior angles moderately rounded, anterior margin straight and seen from behind strongly tridentate, margins strongly reflexed, between labrum and sides of clypeus distinctly incised; lateral margin and ocular canthus produce an indistinct angle; surface weakly carinate medially, coarsely, densely punctate, with erect, long and robust setae; frontoclypeal suture finely incised, medially angled; smooth area anterior to eye small and flat, twice as wide as long; ocular canthus short and wide (1/3 of ocular diameter), finely densely punctate, with a terminal seta. Frons dull, with dense and fine punctures, with a few single setae beside eyes and behind frontoclypeal suture. Eyes moderately large, ratio diameter/ interocular width: 0.67. Antenna with ten antennomeres; club with three antennomeres and straight, 1.2 times as long as remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum moderately transverse, widest shortly before base, lateral margins evenly convex and convergent in anterior half, anterior angles distinctly produced and sharp, posterior angles blunt, rounded at tip; anterior margin straight, with fine marginal line, base without marginal line; surface moderately finely and densely punctate, with minute setae in punctures and a few long setae on anterior and lateral disc; anterior and lateral margin robustly setose; hypomeron carinate, not produced ventrally. Scutellum wide, triangular, with fine, sparse punctures.

Elytra widest at posterior third, striae finely impressed, finely and densely punctate, intervals weakly convex, with fine, sparse punctures concentrated along striae and with minute setae in punctures, odd intervals with a few long single setae; epipleural margin fine, ending at external apical 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 moderately shiny, coarsely and densely punctate, nearly glabrous, metasternal disc sparsely covered with fine, short setae; metacoxa 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; penultimate sternite with a wide chitinous and shiny rim being as wide as median sternite. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.83. Pygidium strongly convex, shiny, finely and densely punctate, without smooth midline, except minute setae in punctures glabrous.

Legs short and wide, dull; femora with two longitudinal rows of setae, finely and sparsely punctate. Anterior margin of metafemur acute, without adjacent serrated line, anterior row of setae nearly completely reduced; posterior ventral margin smooth, strongly widened at ventral apex, dorsal posterior margin smooth, neither serrate, glabrous. Metatibia short and wide, widest at middle, ratio of width/length: 1/2.5, sharply carinate dorsally, with two groups of spines, basal group shortly behind middle, apical group at three quarters of metatibial length, in basal half with a few short and robust single setae; lateral face longitudinally convex, on base and sides sparsely punctate, otherwise smooth and glabrous; ventral margin finely serrate, with five 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, glabrous; first metatarsomere as long as following two tarsomeres combined and as long as dorsal tibial spur. Protibia short, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Fig. 30 I–K. Habitus: Fig. 30L . Female unknown.

Diagnosis. Maladera subtruncata ( Fairmaire, 1887) differs from M. senta (Brenske) and M. pseudosenta Ahrens, Fabrizi & Liu , sp. n. (in males) in having a longer antennal club (1.2 times as long as the remaining antennomeres combined) and the strongly tridentate anterior margin of the labroclypeus (seen from posterior).

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

Remarks. Only one syntype specimen, a female, is known, which is here designated as lectotype. The specimens from Nabanhe match the lectotype almost perfectly.

Distribution. See map ( Fig. 103 ) and Table 1.

Figures

FIGURE 30. A–D: Maladera straminea (Moser, 1915) (China: Guangxi: Luoxiang); E–H: M. botrytibia Nomura, 1974 (Thailand: Mae Hong Son); I–L: M. subtruncata (Fairmaire, 1887) (China: Yunnan: Nabanhe). 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 103. Distribution of the Maladera thomsoni group: Maladera jaintiaensis Ahrens & Fabrizi 2016, M. juxianensis sp. n., M. kubeceki sp. n., M. pseudosenta sp. n., M. senta (Brenske, 1897), M. straminea (Moser, 1915), M. subtruncata (Fairmaire, 1887).