Neoserica tramton 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 : 368-370

Neoserica tramton Ahrens & Pham , new species

Fig. 3I–M

Type material examined. Holotype: ♂ “N-Vietnam, Lao Cai Prov., Hoang Lien NP, Tram Ton, N 22°21.197’ E 103°46.513’, 1800-2050m 13.- 16.5.2015, leg. A. Skale ” ( ZFMK) . Paratypes: 1 ♂ “N-Vietnam, Lao Cai Prov., Hoang Lien NP, Tram Ton, N 22°21.197’ E 103°46.513’, 1800-2050m 13.- 16.5.2015, leg. A. Skale ” ( NME) .

Description of the holotype. Length: 6.4 mm; elytral length: 4.7 mm; width: 4.1 mm. Body oblong, dark brown, antennal club and labroclypeus reddish brown, pronotum with some greenish color, dorsal surface dull and except frons nearly glabrous, labroclypeus and anterior two thirds of frons shiny.

Labroclypeus rectangular, distinctly wider than long; lateral margins convex strongly convergent towards strongly rounded anterior angles; anterior margin moderately emarginate medially; margins moderately reflexed; surface weakly elevated medially and shiny, finely and densely punctate, with a few single setae anteriorly. Frontoclypeal suture finely incised, slightly elevated and strongly curved. Smooth area anterior to eye flat, as wide as long. Ocular canthus short and moderately narrow (equal to 1/4 of ocular diameter), finely and sparsely punctate, with a single terminal seta. Frons on anterior two thirds shiny, finely and sparsely punctate, with a few long single setae beside eyes, otherwise glabrous; on posterior third dull, finely and densely punctate, with fine and dense, short setae. Eyes small, ratio diameter/interocular width: 0.58. Antenna with ten antennomeres, club with four antennomeres and straight, 1.2 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 shortly before base; in basal half lateral margins moderately convex and weakly convergent anteriorly, in anterior half margins strongly convex and convergent; anterior angles weakly produced and blunt; posterior angles nearly right-angled and moderately rounded at tip; anterior margin with a fine and complete marginal line, weakly convexly produced medially; surface moderately densely and coarsely punctate, with minute setae in punctures; lateral and anterior border densely setose; basal margin without marginal line; hypomeron distinctly carinate basally. Scutellum long, with fine, very dense punctures, and minute setae in punctures.

Elytra oblong, widest at posterior third; striae weakly impressed, finely and moderately densely punctate; intervals flat, with sparse, fine punctures concentrated along striae, with minute setae in punctures. Epipleural edge fine, ending at moderately curved external apical angle of elytra; epipleura densely setose; apical border with a fine rim of 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: 1/1.42. Pygidium weakly convex and dull, coarsely and densely punctate, without smooth midline, with sparse long and short minute setae in posterior half.

Legs moderately slender. Femora with two longitudinal rows of setae, finely and sparsely punctate. Metafemur dull and sparsely finely punctate; anterior margin acute, behind anterior margin without serrated line; posterior margin in apical half serrated ventrally and moderately widened at apex; posterior margin finely serrated dorsally, glabrous. Metatibia slender and long, widest at apex, ratio of width/length: 1/4.4; dorsal margin longitudinally convex, with two groups of spines; basal group at middle, apical group at three quarters 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 setae, with the apical one being more distant; medial face finely and densely punctate, glabrous, apex sharply truncate interiorly near tarsal articulation. Tarsomeres ventrally with sparse, short setae, not carinate laterally, with fine sparse punctures bearing each a short seta dorsally; metatarsomere 1 distinctly longer than 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. 3I–L . Habitus: Fig. 3M .

Female unknown.

Variation. Length: 6.4–7.6 mm; elytral length: 4.7–5.1 mm; width: 4.1–4.4 mm.

Diagnosis. Neoserica tramton Ahrens & Pham , new species differs from N. koelkebecki Liu, Fabrizi, Bai, Yang & Ahrens, 2014 from South Korea by the dorsal margin of metatibia longitudinally convex and by the left paramere being almost as long as the right one.

Etymology. Named after the type locality, Tram Ton (noun in apposition).

Figures

FIGURE 3. A–D: Neoserica allosigillata Ahrens & Pham, new species (holotype); E–H: N. diplospinosa Ahrens & Pham, new species (holotype); I–M: N. tramton Ahrens & Pham, new species (holotype). A, E, I: Aedeagus, left side lateral view; C, G, L: Aedeagus, right side lateral view; B, F, K: Parameres, dorsal view; J: aedeagus, dorsal view; D, H, M: Habitus (not to scale). Scale: 0.5 mm.