Amiserica sacculiforceps 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 : 8-9

Amiserica sacculiforceps Ahrens, Fabrizi & Liu , new species

Figures 1E–H , 15

Type material examined. Holotype: ♂ “ China, Shaanxi, Taibashan Range , 1900m, Houzhenzi vill. env., 1– 12.viii[sic!].1999, 33°53N, 107°49E, V. Siniaev & A. Plutenko lgt. / 841 Sericini : Asia spec.” ( CP) . Paratypes: 2 ♂♂ “ China, Shaanxi, Taibashan Range, 1900m, Houzhenzi vill. env., 1–12.viii[sic!].1999, 33°53N, 107°49E, V. Siniaev & A. Plutenko lgt.” ( CP, ZFMK) , 1 ♂ “ China-Shaanxi, SW Tsinling Mts., Taiping vill., 33°33’N, 106°43’E, June 2000, 1500–2000m, Siniaev & Plutenko leg.” ( CP, ZFMK) , 1 ♂ “ Liuba , Shaanxi, 16.V.1982, leg. Hu Huiwei ” ( MNAFU) .

Description of the holotype. Length: 8.0 mm, length of elytra: 5.9 mm, width: 4.6 mm. Body oblong, 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 moderately convergent to weakly 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, coarsely and densely punctate, with numerous long erect setae; frontoclypeal suture invisible; smooth area anterior to eye three 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 moderately densely punctate on anterior two thirds, posterior third impunctate, with sparse, long setae beside eyes and on disc. Eyes large, ratio of diameter/interocular width: 0.89. Antenna with ten antennomeres, club with three antennomeres, slightly reflexed externally, 2.8 times as long as remaining antennomeres combined. Mentum elevated and flattened anteriorly.

Pronotum widest at base, lateral margins in basal half subparallel, in anterior part strongly curved and convergent to moderately produced and nearly blunt anterior angles, posterior angles nearly rectangular; 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 in posterior third, 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: 1/1.36. 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: 1/4.0, sharply carinate dorsally, with the basal group of spines at 3/5 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 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. 1E–G . Habitus: Fig. 1H . Female unknown.

Variation. Length: 8.0– 9.1 mm, length of elytra: 5.9–6.5 mm, width: 4.6–5.0 mm.

Diagnosis. The species differs from A. rufidula by the lacking serrated line of metatibia, the larger and more elongate body as well as the narrower legs; the parameres are longer and narrower and the dorsoapical processes of phallobase narrower.

Etymology. The name of the new species is derived from the combined Latin words sacculus (small sac) and forceps (forceps), with reference to the fine membraneous sacs at the apex of the parameres typical for this species group.

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.