Amiserica eucurviforceps 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 : 20-22

Amiserica eucurviforceps Ahrens, Fabrizi & Liu , new species

Figures 5A–D , 13

Type material examined. Holotype: ♂ “N. Vietnam: Lao Cai Prov. 23km W of Sa Pa 2/VII/1997 ca. 1600m collr. C.L. Li / Sericini Asia spec. 220” ( ZFMK) . Paratypes: 1 ♂ “N Vietnam - Lao Cai province, Hoang Lien Natl. Park: surr. Sa Pa pass, at light (~ 1900m) 27.V.–2.VI.2011 / L. Bartolozzi, S. Bambi, F. Fabiano, E. Orbach leg. (Num. Maggazzino 2909)” ( MZUF) , 3 ♂♂ “ Coll. I.R.Sc. N.B. Vietnam, Hoang Lien N.P. 22°21'00''N 103°46'20''E 1.–5.vii.2013 light trap Leg. J. Constant & J. Bresseel, I.G.: 32.454” ( ISNB) , 2 ♂♂ “ Coll. I.R.Sc. N.B. Vietnam, Hoang Lien N.P. 22°21'00''N 103°46'20''E 1.–5.vii.2013 night collecting Leg. J. Constant & J. Bresseel, I.G.: 32.454” ( ISNB) , 3 ♂♂ “ Coll. I.R.Sc. N.B. Vietnam, Hoang Lien N.P. 22°21'00''N 103°46'20''E 1.–5.vii.2013 Malaise trap Leg. J. Constant & J. Bresseel, I.G.: 32.454” ( ISNB) , 7 ♂♂, 8 ♀♀ “ THAILAND, N: Chang Mai Prov. Doi Pha Hom Pok, 20.–26.II.2004 leg. T. Ihle ” ( ZFMK) , 2 ♂♂ “ THAILAND, N: Chang Mai Prov. Doi Pha Hom Pok, 23.– 29.I.2004 leg. T. Ihle ” ( ZFMK) , 1 ♂, 2 ♀♀ “ THAILAND, N: Chang Mai Prov. Doi Pha Hom Pok, 14.–23.III.2004 leg. T. Ihle ” ( ZFMK) .

Description of the holotype. Length: 5.4 mm, length of elytra: 3.7 mm, width: 3.1 mm. Body oblong, brown, surface dull, labroclypeus shiny, antenna yellowish brown, dorsal surface almost glabrous.

Labroclypeus subtrapezoidal, widest at base, lateral margins weakly convex and convergent to moderately rounded anterior angles, lateral border and ocular canthus producing a distinct obtuse angle; anterior margin weakly emarginate medially, margins weakly reflexed; surface flat and shiny, finely and sparsely punctate, with a few coarse punctures bearing each a long erect seta; 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, anterior quarter shiny, finely and moderately densely punctate, with sparse evenly distributed long setae. Eyes moderately large, ratio of diameter/interocular width: 0.68. Antenna with ten antennomeres, club with four antennomeres, slightly reflexed externally, 2.5 times as long as remaining antennomeres combined. Mentum elevated and flattened anteriorly.

Pronotum transverse, widest at base, lateral margins in basal half subparallel, in anterior part strongly curved and convergent to moderately produced and weakly rounded and almost blunt anterior angles, posterior angles nearly rectangular; anterior margin distinctly convex, with the marginal line narrowly 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, punctures with minute setae only, along midline basally impunctate.

Elytra oblong, widest shortly behind the 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 membraneous, with a distinct rim of microtrichomes.

Ventral surface dull, with coarse and dense punctures, with short and fine setae in punctures. Metacoxa laterally additionally 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: 1/1.57. Pygidium weakly convex and dull, with coarse, dense punctures and numerous fine, long setae.

Legs moderately 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: 1/3.3, sharply carinate dorsally, with the basal group of spines reduced into scattered single spines, the apical one at 5/6 of metatibial length, basally with a few single spines in punctures; beside dorsal margin with a continuously serrated line until the distal group of spines being convergent with dorsal margin at apex, between serrated line and dorsal finely sparsely punctate; lateral face longitudinally convex, with dense and coarse punctures bearing each a minute seta; ventral margin serrated, with four fine and long, equidistant robust setae; medial face impunctate and glabrous; apex interiorly near tarsal articulation shallowly concavely sinuate. Tarsomeres dorsally impunctate, ventrally with short, sparse setae. Metatarsomeres ventrally with a strongly serrated ridge, laterally not carinate; first metatarsomere little shorter than following two tarsomeres combined and a quarter of its length longer then dorsal tibial spur. Protibia moderately long, bidentate, protarsal claws symmetrical, basal tooth of inner claw simply but sharply truncate at apex.

Aedeagus: Fig. 5A–C . Habitus: Fig. 5D .

Variation. Length: 5.4–7.9 mm, length of elytra: 3.7–5.5 mm, width: 3.1–4.6 mm. Female: body size generally little larger; eyes smaller than in male, ratio of diameter/interocular width: 0.5; antennal club as long as remaining antennomeres combined, pygidium weakly convex.

Diagnosis. Amiserica eucurviforceps Ahrens, Fabrizi & Liu , new species differs from A. antennalis by the metatibia which is widest at middle having the basal group of spines reduced to a single robust seta; furthermore, the apex of the phallobase possesses in A. eucurviforceps on the right side a short dorsolateral process.

Etymology. The name of the new species is derived from the combined Greek prefix eu (good), the combined Latin words curvus (curved) and forceps (forceps), with reference to the shape of the curved right paramere.

Figures

FIGURE 5. A–D: Amiserica eucurviforceps Ahrens, Fabrizi & Liu, new species (holotype); E–H: A. pseudoincisa Ahrens, Fabrizi & Liu, new species (holotype). A, E: Aedeagus, left side lateral view; C, G: Aedeagus, right side lateral view; B, F: Parameres, dorsal view; D, H: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 13. Distribution of the species of the Amiserica rufidula group, part 1.