Amiserica piaoac 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 : 29-30

Amiserica piaoac Ahrens, Fabrizi & Liu , new species

Figures 7A–E , 14

Type material examined. Holotype: ♂ “ Coll. I.R.Sc.N.B. Vietnam: Pia Oac Mt. NR 22°36’ / 105°53’E 04-06-VIII-2010 / I.G. 31.668 Light Trap Leg. J. Constant & P. Limbourg ” ( ISNB).

Description of the holotype. Length: 7.0 mm, length of elytra: 5.1 mm, width: 3.9 mm. Body oblong, reddish brown, surface dull, labroclypeus shiny, antenna yellowish brown, dorsal surface almost glabrous.

Labroclypeus wide, subtrapezoidal, widest at base, lateral margins weakly convex and convergent to weakly rounded anterior angles, lateral border and ocular canthus producing a distinct angle; anterior margin bluntly emarginate medially, margins weakly reflexed; surface flat and shiny, finely and coarsely, densely punctate, with a few long erect setae in a transverse line at anterior third; frontoclypeal suture indistinctly impressed and angled medially; smooth area anterior to eye large, 1.2 times as wide as long. Ocular canthus moderately long and narrow, finely and sparsely punctate, with a short terminal seta, equal to 1/2.5 of ocular diameter. Frons dull in posterior half, anterior half moderately shiny, finely and densely punctate in anterior two third, with a few long setae beside eyes, behind frontoclypeal suture, and on posterior disc, punctation on posterior third less dense and glabrous. Eyes moderately large, ratio of diameter/interocular width: 0.58. Antenna with ten antennomeres, club with four antennomeres, slightly reflexed externally, 2.8 times as long as remaining antennomeres combined. Mentum elevated and flattened anteriorly.

Pronotum widest at middle, lateral margins in basal half weakly convex and weakly convergent towards base, in anterior part strongly curved and convergent to moderately produced and blunt anterior angles, posterior angles blunt; anterior margin almost straight, its marginal line widely lacking; 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 dense punctures, smooth on basal midline, punctures with minute setae only.

Elytra oblong, widest in posterior third, striae distinctly impressed, with fine and dense punctures; intervals moderately convex, with fine, evenly and moderately dense punctures, punctures with minute setae only, on odd intervals with a few short 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: 1/1.46. 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 long, widest at apex, ratio width/length: 1/3.9, sharply carinate dorsally, with the basal group of spines at middle, the apical one at 5/6 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 sparse and robust punctures bearing each a minute seta; ventral margin serrated, with three fine and long, robust setae (in holotype abraded but recognizable by their serrated punctures) 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 lacking in holotype. Protibia moderately long, bidentate, protarsal claws symmetrical, basal tooth of inner claw simply but sharply truncate at apex.

Aedeagus: Fig. 7A–D . Habitus: Fig. 7E . Female unknown.

Diagnosis. Amiserica piaoac Ahrens, Fabrizi & Liu , new species differs from A. jiuhuensis Ahrens, Fabrizi & Liu , new species and A. fengyangensis Ahrens, Fabrizi & Liu , new species by the shorter parameres, being covered by more than their half by the dorsal processes of phallobase.

Etymology. The new species is named after the type locality, Pia Oac (noun in apposition).

Figures

FIGURE 7. A–E: Amiserica piaoac Ahrens, Fabrizi & Liu, new species (holotype); F–I: A. fengyangensis Ahrens, Fabrizi & Liu, new species (holotype); J–N: A. jiuhuensis Ahrens, Fabrizi & Liu, new species (holotype). A, F, J: Aedeagus, left side lateral view; D, H, M: Aedeagus, right side lateral view; C, G, K: Parameres, dorsal view; B, L: Aedeagus, dorsal view; E, I, N: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 14. Distribution of the species of the Amiserica rufidula group, part 2.