Amiserica zhongtiaoshanensis Ahrens, Fabrizi & Liu, 2021

Ahrens, Dirk, Liu, Wangang, Pham, Phu Van & Fabrizi, Silvia, 2021, An overview on the genus Amiserica Nomura, 1974 (Coleoptera: Scarabaeidae: Melolonthinae: Sericini), Zootaxa 5050 (1), pp. 1-63 : 9-11

Amiserica zhongtiaoshanensis Ahrens, Fabrizi & Liu , new species

Figures 1I–M , 15

Type material examined. Holotype: ♂ " China-Shanxi Yongji-Zhongtiaoshan mts. 4.5.– 12.5.2004 leg. E. Kučera / Sericini Asia spec. 1054" ( ZFMK) . Paratype: 1 ♂ " China, Shaanxi prov., 8–9.v.2011 110 km NEE Xian, Huayin vill. 34°29.5'N, 110°05.1'E, 1275m M. Balke & J. Hájek leg." ( NMPC) .

Description of the holotype. Length: 8.2 mm, length of elytra: 5.9 mm, width: 4.8 mm. Body oblong, dark reddish brown, surface dull, labroclypeus shiny, antenna yellowish brown, dorsal surface almost glabrous.

Labroclypeus moderately wide, subtrapezoidal, widest at base, lateral margins weakly convex and convergent to strongly rounded anterior angles, lateral border and ocular canthus producing a distinct angle; anterior margin weakly emarginate medially, margins weakly reflexed; surface weakly convex and shiny, coarsely and densely punctate, with numerous long erect setae; frontoclypeal suture indistinctly impressed and angled medially; smooth area anterior to eye 1.5 times as wide as long. Ocular canthus moderately long and narrow, finely and sparsely punctate, with a short terminal seta, equal to 1/3 of ocular diameter. Frons dull, finely and densely punctate in anterior two third, with sparse long setae beside eyes and on disc, posterior third almost impunctate. Eyes very large, ratio of diameter/interocular width: 0.93. Antenna with ten antennomeres, club with three antennomeres, slightly reflexed externally, 2.3 times as long as remaining antennomeres combined. Mentum elevated and flattened anteriorly.

Pronotum widest at base, lateral margins in basal half straight and weakly convergent anteriorly, in anterior part strongly curved and convergent to moderately produced and blunt anterior angles, posterior angles blunt; anterior margin distinctly convex, with the marginal line widely interrupted at middle; basal margin without marginal line; surface with dense and coarse punctures each bearing a minute seta, otherwise glabrous; anterior and lateral borders sparsely setose; hypomeron carinate, basal margin of hypomeron not produced ventrally. Scutellum triangular, apex sharp, with coarse and moderately dense punctures, smooth on basal midline, punctures with minute setae only.

Elytra oblong, widest shortly behind middle, striae distinctly impressed, with fine and dense punctures; intervals moderately convex, with fine and moderately dense punctures concentrated along striae, punctures with minute setae only, on penultimate lateral interval with a few long erect fine setae; epipleural edge moderately strong, ending at strongly rounded external apical angle of elytra, epipleura densely setose, apical border narrowly membraneous, with a rim of short microtrichomes.

Ventral surface dull, with coarse and dense punctures, glabrous except minute setae in punctures. Metacoxa only laterally with a few robust longer setae. Abdominal sternites finely and densely punctate and minutely setose, each sternite with a distinct transverse row of coarse punctures each bearing a short, robust seta. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.37. Pygidium strongly convex and dull, with coarse, dense punctures and a few fine, long setae on posterior half.

Legs slender; femora finely densely and coarsely punctate and glabrous, except for minute setae of punctures, with two longitudinal rows of setae; anterior margin of metafemur acute, with an adjacent continuously serrated line, ventral posterior margin weakly widened in apical half but not serrate, dorsal posterior margin completely smooth as well. Metatibia slender and moderately long, widest at apex, ratio width/length: 1/3.6, sharply carinate dorsally, with the basal group of spines at middle the apical one at 4/5 of metatibial length, basally with a few single spines in punctures; beside dorsal margin without a continuously serrated line, only around coarse spine-bearing punctures serrated, beside dorsal margin finely punctate; lateral face longitudinally convex, with dense and coarse punctures bearing each a minute seta; ventral margin serrated, with three fine and long, robust setae of which the distal one is more distant from the others; medial face impunctate and glabrous; apex interiorly near tarsal articulation shallowly concavely sinuate. Tarsomeres dorsally impunctate, ventrally with short, dense setae. Metatarsomeres ventrally with a strongly serrated ridge, laterally not carinate; first metatarsomere distinctly shorter than following two tarsomeres combined and little longer than dorsal tibial spur. Protibia moderately long, bidentate, protarsal claws symmetrical, basal tooth of inner claw simply but sharply truncate at apex.

Aedeagus: Fig. 1I–L . Habitus: Fig. 1M . Female unknown.

Variation. Length: 8.2–9.1 mm, length of elytra: 5.9–6.2 mm, width: 4.7–4.8 mm.

Diagnosis. The species differs from A. sacculiforceps Ahrens, Fabrizi & Liu , new species by the subsymmetrical dorsolateral processes of phallobase and by the left paramere being not widened at dorsal margin before apex.

Etymology. The new species is name after its type locality, Zhongtiaoshan mts.

Figures

FIGURE 1. A–D: Amiserica rufidula Nomura, 1974 (Taiwan: Tao Yuan Co.); E–H: A. sacculiforceps Ahrens, Fabrizi & Liu, new species (holotype); I–M: A. zhongtiaoshanensis Ahrens, Fabrizi & Liu, new species (holotype). A, E, I: Aedeagus, left side lateral view; C, G, L: Aedeagus, right side lateral view; B, F, J: Parameres, dorsal view; K: Aedeagus, dorsal view; D, H, M: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 15. Distribution of the species of the Amiserica rufidula group, part 3.