Amiserica nahang 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 : 50-51

Amiserica nahang Ahrens, Fabrizi & Liu , new species

Figures 12F–J , 19

Type material examined. Holotype: ♂ “VIETNAM-N Tuyen Quang pr. SE-E env. of Na Hang , 22°17’30’’– 22°30’N, 105°26’–28’E, 200–700m L. Dembicky leg., 1.–12.V.2010 ” ( ZFMK) . Paratypes: 1 ♀ “VIETNAM-N Tuyen Quang pr. SE-E env. of Na Hang , 22°17’30’’– 22°30’N, 105°26’–28’E, 200–700m L. Dembicky leg., 1.– 12.V.2010 ” ( ZFMK) , 3 ♂♂, 3 ♀♀ “Vietnam-N (Na Hang) 16 km NW Ha Noi, NE env. of Na Hang 5.– 10.6.1996 150–200 m lg. A. Napolov & I. Roma ” ( CNA, ZFMK) .

Description of the holotype. Length: 5.9 mm, length of elytra: 3.9 mm, width: 3.0 mm. Body oblong, yellow, frons blackish, surface shiny, antenna yellow, dorsal surface glabrous.

Labroclypeus subtrapezoidal, widest at base, lateral margins strongly convex and convergent to moderately rounded anterior angles, lateral border and ocular canthus producing a distinct angle; anterior margin weakly emarginate medially, margins moderately reflexed; surface convex and shiny, finely and irregularly, moderately densely punctate, with a few long erect setae in anterior part; frontoclypeal suture finely incised, angled medially; smooth area anterior to eye three times as wide as long. Ocular canthus short and wide, finely and sparsely punctate, with a short terminal seta, equal to 1/3 of ocular diameter. Frons finely and densely punctate, with a few long setae beside eyes. Eyes moderately large, ratio of diameter/interocular width: 0.7. Antenna with nine antennomeres, club with three antennomeres, straight, 1.2 times as long as remaining antennomeres combined. Mentum elevated and flattened anteriorly.

Pronotum widest at base, lateral margins in basal half weakly convex and nearly subparallel, in anterior part moderately curved and convergent to distinctly produced and sharp anterior angles, posterior angles blunt; anterior margin distinctly convex, marginal line fine and complete; basal margin without marginal line; surface with dense and fine punctures, glabrous; anterior and lateral borders sparsely setose; hypomeron carinate, basal margin of hypomeron not produced ventrally. Scutellum triangular, apex sharp, with fine and dense punctures, glabrous.

Elytra oblong, widest at middle, striae distinctly impressed, with fine and dense punctures; intervals moderately convex, with fine and dense punctures concentrated along striae, glabrous, only minute setae in punctures; 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 shiny, with coarse and dense punctures, glabrous except a minute seta 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: 1/1.6. Pygidium moderately convex and shiny, with coarse, dense punctures and a few fine, short and long setae on apical half.

Legs moderately slender; femora finely densely and coarsely punctate and glabrous, with 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, smooth, not serrate, dorsal posterior margin also smooth. Metatibia moderately wide and long, widest at middle, ratio width/length: 1/2.7, moderately carinate dorsally, with only one group of spines at 5/6 of metatibial length, basally with a few single spines in punctures; beside dorsal margin with a continuously serrated line until 3/4 of metatibial length, convergent with dorsal margin, between serrated line and dorsal margin finely punctate and with long setae; lateral face longitudinally convex, with sparse and fine punctures bearing each a minute seta; ventral margin finely serrated, with three fine and long, robust equidistant setae; medial face sparsely finely punctate, punctures with minute setae; apex interiorly near tarsal articulation shallowly truncate. Tarsomeres dorsally moderately densely punctate, ventrally with short, sparse setae. Metatarsomeres ventrally with a strongly serrated ridge and sparsely setose, 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. 12F–I . Habitus: Fig. 12J .

Variation. Length: 5.1–6.2 mm, length of elytra: 3.7–4.5 mm, width: 3.0– 3.4 mm. Female: Eyes only little smaller than in male (ratio of diameter/interocular width: 0.64); antennal club little shorter than remaining antennomeres combined; pygidium strongly convex at middle.

Diagnosis. Amiserica nahang Ahrens, Fabrizi & Liu , new species differs from Amiserica gulinqin Ahrens, Fabrizi & Liu , new species by the longer antennal club, the parameres having both large basal lobes, and being strongly bent at middle.

Etymology. The new species is named after one its type locality, Na Hang (noun in apposition).

Figures

FIGURE 12. A–E: Amiserica lucidiflava Ahrens, Fabrizi & Liu, new species (holotype); F–J: A. nahang Ahrens, Fabrizi & Liu, new species (holotype); K–O: A. pappi Ahrens, Fabrizi & Liu, new species (holotype). A, F, K: Aedeagus, left side lateral view; D, I, N: Aedeagus, right side lateral view; B, G, L: Aedeagus, dorsal view; C, H, M: Parameres, dorsal view; E, J, O: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 19. Distribution of the species of the Amiserica gunlinqin group.