Neoserica allosigillata 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 : 366-367

Neoserica allosigillata Ahrens & Pham , new species

Fig. 3A–D

Type material. Holotype: ♂ “ Coll. I.R. Sc. N.B. Vietnam: Tam Dao N.P. 25-28-VIII-2010 / Light Trap Leg. J. Constant & P. Limbourg I.G.31.668 / 1100 Sericini Asia spec.” ( ISNB) . Paratypes: 2 ♂♂ “ Coll. I.R. Sc. N.B. Viet- nam: Tam Dao N.P. 25-28-VIII-2010 / Light Trap Leg. J. Constant & P. Limbourg I.G.31.668” ( ISNB, ZFMK) , 1 ♂ “Vietnam-N (Tam Dao), 55 km NW Hanoi, Tam Dao vill. env. 1998 850-900 m 1.-14.8. lg. A. Napolov ” ( ZFMK) , 1 ♂ “Tam Dao N. P., Vinh Phuc Province, 3.vii.2013, light trap ” ( IEBR) .

Description of the holotype. Body length: 6.1 mm; elytral length: 4.2 mm; width: 3.8 mm. Body oval, reddish brown, antennal club and ventral surface yellowish, dorsal surface dull and except frons nearly glabrous, labroclypeus and anterior half of frons shiny.

Labroclypeus subtrapezoidal, wider than long, widest at base; lateral margins strongly convex and convergent towards strongly rounded anterior angles; anterior margin narrowly but distinctly emarginate medially; margins weakly reflexed; surface convexly elevated medially and shiny, finely and very sparsely punctate, with a few single setae anteriorly. Frontoclypeal suture finely incised and slightly elevated, medially bent. Smooth area anterior to eye small, weakly 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 half shiny, finely and sparsely punctate, with a few long single setae beside eyes, otherwise glabrous, limit between dull and shiny area v-shaped; on posterior half dull (with toment), finely and densely punctate, with fine, short setae. Eyes small, ratio diameter/interocular width: 0.5. Antenna with ten antennomeres, club with four antennomeres and straight, as long as remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly. Labrum transverse, short, not produced medially, with weak median sinuation.

Pronotum subtrapezoidal, widest at base; lateral margins in basal half straight, moderately convergent, and weakly curved, in anterior half strongly convex and convergent anteriorly; anterior angles strongly produced and sharp; posterior angles blunt; anterior margin weakly convex, with a fine marginal line; surface densely and finely punctate, with minute setae in punctures; lateral and anterior sparsely setose; basal margin without marginal line; hypomeron distinctly carinate basally. Scutellum short, with fine, dense punctures, and minute setae in punctures, on basal midline impunctate.

Elytra short, widest shortly behind middle; striae weakly impressed, finely and moderately densely punctate; intervals weakly convex, with sparse, fine punctures concentrated along striae, with minute setae in punctures; penultimate lateral interval with a few long setae. 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: 1/1.44. Pygidium moderately convex and dull, moderately densely punctate, without smooth midline, with minute setae in punctures and numerous long setae on apical 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 moderately slender and short, widest at apex, ratio of width/length: 1/2.8; dorsal margin sharply carinate, with two groups of spines; basal group shortly behind 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 impunctate, glabrous, apex bluntly truncate interiorly near tarsal articulation. Tarsomeres ventrally with sparse, short setae, not carinate laterally, with fine, very sparse punctures dorsally; metatarsomere 1 almost 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. 3A–C . Habitus: Fig. 3D .

Female unknown.

Variation. Length: 5.1–6.1 mm; elytral length: 3.8–4.2 mm; width: 3.7–3.8 mm.

Diagnosis. Neoserica allosigillata Ahrens & Pham , new species differs from N. sigillata (Brenske, 1897) by the shorter antennal club and by the shape of parameres; the basal lobe of the right paramere is much longer and has a sharp mesal tooth at base.

Etymology. The name of the new species is derived from the combined Greek prefix allo - (different) and the species name sigillata with reference on the similar shape of the parameres to Neoserica sigillata (Brenske, 1897) .

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.