Neoserica fragilis Ahrens & Pham, 2021

Ahrens, Dirk & Pham, Phu Van, 2021, Additions to the Neoserica calva group from continental South East Asia (Coleoptera: Scarabaeidae: Melolonthinae: Sericini), Zootaxa 5032 (3), pp. 357-378 : 362-363

Neoserica fragilis Ahrens & Pham , new species

Fig. 2A–D

Type material. Holotype: ♂ “LAOS-NE, Hua Phan prov. , 20°12’N, 104°01’E, PHU PHAN Mt., 1500-1900m 17.5.- 3.6.2007 leg. C. Holzschuh ” ( ZFMK) . Paratypes: 2 ♂♂ “ LAOS, Xieng Khouang Prov., 19°37-8’N 103°20- 1’E, Phonsavan (30 km NE); Phou Sane Mt. , 1400-1700 m, 10.-30.v.2009, D. Hauck leg. / NHMB Basel, NMPC Prague Laos 2009 Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň ” ( NHMB) , 1 ♂ “ LAOS, Xieng Khouang Prov., 19°38.20’N 103°20.20’E, Phonsavan (30 km NE); Phou Sane Mt., 1420 m, 10.-30.v.2009, V. Kubáň leg. / Secondary mountain forest, flight interception trap Laos 2009 Expedition NHMB Basel, NMPC Prague” ( NHMB) , 1 ♂ “LAOS-NE, Hua Phan prov., 20°12’N, 104°01’E, Phu Phan Mt. ~ 1750m, 17.v.-3.vi.2007, Vit Kubáň leg.” ( NMPC) , 3 ♂♂ “ LAOS, Xieng Khouang Prov., 19°37-8’N 103°20-1’E, 30 km NE Phonsavan; Ban Na Lam -> Phou Sane Mt. , 1300-1700 m, 10.-30.v.2009, M. Geiser leg. / NHMB Basel, NMPC Prague Laos 2009 Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň ” ( NHMB) , 1 ♀ “LAOS-NE, Hua Phan prov., 20°12’N, 104°01’E, Phu Phan Mt. 1750m, 17.5.- 3.6.2007, Vit Kubáň leg.” ( ZFMK) , 2 ♀♀ “LAOS-NE, Huoa Phan prov., 20°13’09-19’’N, 103°59’54’’- 104°00’03’’E, 1480-1510m, Phou Pane Mt. 22.iv.-14.v.2008, Vit Kubán leg.” ( ZFMK, NMPC) , 4 ♀♀ “NE-Laos: Hua Phan prov.; Ban Saleui, Phou Pan ( Mt. )- 20°12’N, 104°01’E 11.iv.-15.v.2012, 1300-1900m leg. C. Holzschuh - ZFMK Ankauf 2012/13” ( ZFMK) , 2 ♂♂, 4 ♀♀ “NE-Laos: Hua Phan prov.; Ban Saleui, Phou Pan ( Mt. )- 20°12’N, 104°01’E 11.iv.-15.v.2012, 1300-1900m leg. C. Holzschuh - ZFMK Ankauf 2012” ( ZFMK) , 1 ♀ “NE-Laos: Hua Phan prov.; Ban Saleui, Phou Pan ( Mt. )- 20°12’N, 104°01’E 1300-1900m 01.-31.V.2011, leg. C. Holzschuh ZFMK Ankauf 2011” ( ZFMK) , 1 ♂ “LAOS-NE: Hua Phan prov.; 20°12’N, 104°01’E, Phu Phan Mt. , 1500-1900m, 17.5.- 3.6.2007, leg. C. Holzschuh ” ( ZFMK) .

Description of the holotype. Body length: 4.6 mm, length of elytra: 3.0 mm, width: 2.8 mm. Body oval, dark reddish brown, elytra and pronotal margins reddish brown, antennal club and ventral surface yellowish brown, dorsal surface dull and except frons nearly glabrous, labroclypeus and anterior two thirds of frons moderately shiny.

Labroclypeus subtrapezoidal, little wider than long, widest at base; lateral margins straight and weakly convergent towards strongly rounded anterior angles; anterior margin straight; margins strongly reflexed; surface flat and moderately shiny, coarsely and densely punctate, with numerous long, erect setae. Frontoclypeal suture indistinct, not elevated and curved. Smooth area anterior to eye convex, 1.5 times as wide as long. Ocular canthus moderately long and narrow (equal to 1/3 of ocular diameter), impunctate, with a single terminal seta. Frons on anterior two thirds shiny, finely and irregularly densely punctate, with a few long single setae beside eyes and behind frontoclypeal suture, otherwise glabrous; on posterior third dull (with toment), but glabrous and impunctate. Eyes small, ratio diameter/interocular width: 0.49. Antenna with ten antennomeres, club with four antennomeres and weakly reflexed, 1.6 times as long as remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly. Labrum transverse, short, not produced medially, with weak median sinuation.

Pronotum transverse, widest at middle; lateral margins strongly and evenly convex, well-convergent anteriorly and posteriorly; anterior angles moderately produced and rectangular, sharp at tip; posterior angles blunt; anterior margin straight, with a fine marginal line, entire anterior margin with a dense fringe of short setae; surface densely and coarsely punctate, with minute setae in punctures; lateral and anterior border sparsely setose; basal margin without marginal line; hypomeron distinctly carinate basally. Scutellum long, with coarse sparse punctures, and minute setae in punctures.

Elytra short, widest at posterior third; striae weakly impressed, finely and moderately densely punctate; intervals almost flat, with sparse, fine punctures concentrated along striae, impunctate medially, with minute setae in punctures. Epipleural edge fine, ending at moderately curved external apical angle of elytra; epipleura densely setose; apical border with a very fine rim of short microtrichomes (visible at 100x magnification).

Ventral surface dull, finely and densely punctate. Metasternum except long setae on disc nearly glabrous, sparsely covered with minute setae in punctures. Metacoxa glabrous, with a few single setae laterally. Abdominal sternites finely and densely punctuate, glabrous except minute setae in punctures, with a transverse row of coarse punctures each bearing a robust long seta. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.5. Pygidium strongly convex and dull, coarsely densely punctate, without smooth midline, with a few long setae beside apical margin.

Legs moderately slender. Femora with two longitudinal rows of setae, finely and sparsely punctate. Metafemur shiny and sparsely finely punctate; anterior margin acute, behind anterior margin without serrated line; posterior ventral margin in apical half smooth and moderately widened at apex; posterior dorsal margin finely serrated, sparsely setose. Metatibia moderately slender and short, widest at apex, ratio of width/length: 1/3.3; dorsal margin sharply carinate, with two groups of spines; basal group at anterior third, apical group at two thirds of metatibial length; in basal half with a few short robust setae in single robust punctures with serrated margin; external face longitudinally convex, finely and sparsely punctate; ventral margin finely serrated, with three robust equidistant setae; medial face impunctate, glabrous, apex bluntly truncate interiorly near tarsal articulation. Tarsomeres ventrally with sparse, short setae, not carinate laterally, with fine sparse punctures dorsally; metatarsomeres ventrally glabrous, metatarsomere 1 twice as long as dorsal metatibial spur and as long as following two tarsomeres combined. Protibia moderately long, bidentate, bluntly widened laterally before basal tooth; anterior claws symmetrical, basal tooth of inner claw sharply truncate at apex.

Aedeagus: Fig. 2A–C . Habitus: Fig. 2D .

Variation. Body length: 4.2–5.6 mm, length of elytra: 2.9–3.8 mm, width: 2.5–3.4 mm. In some paratypes pronotum and elytra bicolored, some females entirely yellow except the dark head. Female: eyes little smaller, ratio diameter/interocular width: 0.47; antennal club short, with three lamellae, as long as remaining antennomeres combined.

Diagnosis. Neoserica fragilis Ahrens & Pham , new species differs from N. sigillata (Brenske, 1897) and N. napoensis Ahrens, Fabrizi & Liu, 2019 by the left paramere having a large basal lobe, and the right paramere being narrow and long, bent at middle.

Etymology. The name of the species ( fragilis ) is derived from the Latin adjective fragilis, breakable (adjective in nominative case).

Figures

FIGURE 2. A–D: Neoserica fragilis Ahrens & Pham, new species (holotype); E–H: N. chetaoensis Ahrens & Pham, 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.