Amiserica gibbosiforceps 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 : 32-34

Amiserica gibbosiforceps Ahrens, Fabrizi & Liu , new species

Figures 8E–J , 16

Type material examined. Holotype: ♂ “ China, N. Yunnan, env. Xiaguan , 2400m, 29.vii.2002, leg. S. Murzin, I. Shokhin / 834 Sericini : Asia spec.” ( CP) . Paratypes: 8 ♂♂, 4 ♀♀ “ China, N. Yunnan, env. Xiaguan , 2400m, 29.vii.2002, leg. S. Murzin, I. Shokhin ” ( CP, ZFMK) , 1 ♂ “ Muséum Paris 19.VI.2001 Deuve, Mantillieri, Rougerie & Tian leg. / Chine – Yunnan Rés. Huanglian Shan 22°54'N 102°18'E alt. 2080m ” ( MNHN) .

Description of the holotype. Length: 7.6 mm, length of elytra: 5.6 mm, width: 4.1 mm. Body oval, reddish brown, surface shiny, antenna yellowish brown, on head, pronotum, elytra, and pygidium with long setae interspersed with short adpressed ones (setae directed posteriorly). Setae of holotype partly abraded.

Labroclypeus semicircular, widest at base, lateral margins convex and strongly convergent to strongly rounded anterior angles, lateral border and ocular canthus producing an indistinct angle, anterior margin convex, margins weakly reflexed; surface convex medially and shiny, coarsely and densely punctate, partly punctures fusing with each other, with dense long erect setae; frontoclypeal suture finely impressed and weakly bent at middle; smooth area anterior to eye short, four times as wide as long. Ocular canthus short and triangular (1/3 of ocular width), finely and sparsely punctate, glabrous except a short terminal seta. Frons completely shiny, finely and coarsely, very densely punctate, with dense long pilosity, on posterior third almost impunctate and glabrous. Eyes moderately large, ratio of diameter/ interocular width: 0.6. Antenna with ten antennomeres, club with three antennomeres, 1.1 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, anterior angles acute and distinctly produced, posterior angles nearly rectangular; anterior margin strongly convex, its marginal line widely interrupted medially; basal margin without marginal line; surface with very dense and fine punctures and with dense double pilosity, long setae (directed nearly upright or forward) interspersed with short adpressed ones (directed posteriorly); anterior and lateral borders densely setose; hypomeron carinate, basal margin of hypomeron weakly produced ventrally. Scutellum subtriangular, apex sharp, with fine and very dense punctures, with mostly short adpressed setae, erect setae very sparse.

Elytra oval, widest at middle, striae indistinctly impressed, with fine and dense punctures; intervals flat, with fine and evenly dense punctures, with dense double pilosity as in pronotum (short and long adjacent setae directed posteriorly); epipleural edge robust, ending at external apical angle of elytra; epipleura densely setose, apical border broadly membraneous, with a robust rim of microtrichomes.

Ventral surface shiny, with fine and very dense punctures, including metacoxa with dense, adpressed, long setae. Abdominal sternites finely and densely punctate, punctures with short adpressed setae, each sternite with a distinct transverse row of coarse punctures each bearing a long, robust, erect seta. Mesosternum between mesocoxae 1.5 times as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.46. Pygidium weakly convex and iridescent, with fine, dense punctures and dense, short and long setae.

Legs wide and short; femora coarsely and densely punctate, punctures with moderately long adpressed setae, with two longitudinal rows of setae; anterior edge of metafemur acute, with an adjacent and slightly elevated continuously serrated line; posterior margin ventrally weakly widened in apical half but not serrate, posterior margin also dorsally not serrate. Metatibia wide and short, widest at apex, ratio width/length: 1/2.4; dorsal margin sharply carinate, with only one group of spines, basal group of spines reduced to a single spine at 3/4 of metatibial length, apical one at 7/8 of metatibial length, basally without robust single setae, beside dorsal margin with a complete serrated line convergent with dorsal margin behind apical group of spines, between serrated line and dorsal margin finely punctate; lateral face weakly longitudinally convex, with dense and coarse punctures bearing each a short adpressed seta; ventral margin not serrated, with four robust and long, equidistant spines; medial face densely punctate and shortly setose; apex interiorly near tarsal articulation concavely sinuate. Tarsomeres dorsally impunctate and glabrous, ventrally with short and long, dense setae. Metatarsomeres ventrally carinate but not serrated, laterally not carinate; first metatarsomere as long as following tarsomere and as long as dorsal tibial spur. Protibia very short, bidentate, protarsal claws symmetrical, basal tooth of inner claw simply pointed.

Aedeagus: Fig. 8E–I . Habitus: Fig. 8J .

Variation. Length: 7.6–8.0 mm, length of elytra: 5.6–6.2 mm, width: 4.1–4.5 mm. Females are highly similar to the males, but the antennal club is distinctly shorter as in male (being little shorter than remaining antennomeres combined) and the eyes are smaller (ratio of diameter/ interocular width: 0.54).

Diagnosis. Amiserica gibbosiforceps Ahrens, Fabrizi & Liu , new species differs from Amiserica jizuensis Ahrens, Fabrizi & Liu , new species, by the reduced basal group of spines of metatibia, the distinctly shiny body, and the strong dorsal tubercle on dorsoapical phallobase.

Etymology. The name (adjective in the nominative singular) of the new species is derived from the combined Latin words gibbosus (with tubercles) and forceps (forceps), with reference on the shape of the phallobase having a strong tubercle.

Figures

FIGURE 8. A–D: Amiserica jizuensis Ahrens, Fabrizi & Liu, new species (holotype); E–J: A. gibbosiforceps Ahrens, Fabrizi & Liu, new species (holotype); K–N: A. panghongae Ahrens, Fabrizi & Liu, new species (holotype). A, E, K: Aedeagus, left side lateral view; C, I, M: Aedeagus, right side lateral view; B, F: Aedeagus, dorsal view; G, L: Parameres, dorsal view; H: Parameres, ventral view; D, J, N: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 16. Distribution of the species of the Amiserica jizuensis group.