Neoserica judsoni 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 : 360-362

Neoserica judsoni Ahrens & Pham , new species

Fig. 1E–H

Type material. Holotype: ♂ “ LAOS: Vientiane Prov. Ban Van Eue 29.III.1966 / J.L. Gressitt Collector Bishop Museum / Sericini Asia spec. 488” ( BPBM).

Description of the holotype. Body length: 4.2 mm, length of elytra: 3.2 mm, width: 3.0 mm. Body oval, dark brown, head and pronotal margins reddish brown, antennal club yellowish brown, dorsal surface dull and except frons nearly glabrous, labroclypeus and anterior two thirds of frons moderately shiny.

Labroclypeus subtrapezoidal, wider than long, widest at base; lateral margins strongly convex and convergent towards strongly rounded anterior angles; anterior margin weakly 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, not elevated and bent medially. Smooth area anterior to eye weakly convex, 1.5 times as wide as long. Ocular canthus moderately long and narrow (equal to 1/3 of ocular diameter), finely and densely punctate, with a single terminal seta. Frons on anterior two thirds moderately shiny (without dull toment), finely and irregularly densely punctate, with a few long single setae beside eyes, otherwise glabrous; on posterior third dull (with toment), finely and densely punctate, with dense, short setae. Eyes small, ratio diameter/interocular width: 0.55. Antenna with ten antennomeres, club with four antennomeres and weakly reflexed, twice 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; lateral margins strongly and evenly convex, well-convergent anteriorly; anterior angles moderately produced and nearly rectangular, weakly rounded at tip; posterior angles blunt; anterior margin straight, with a very fine marginal line; surface densely and coarsely punctate, with minute setae in punctures; lateral and anterior border densely but shortly setose; basal margin without marginal line; hypomeron distinctly carinate basally. Scutellum long, with fine, very dense punctures, and minute setae in punctures, a wide triangular space mesobasally impunctate.

Elytra short, widest at posterior third; striae weakly impressed, finely and moderately densely punctate; intervals weakly convex, 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 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: 1/1.3. Pygidium weakly convex and dull, sparsely punctate, without smooth midline, with a few 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: 1/2.9; dorsal margin sharply carinate, 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 impunctate, glabrous, apex bluntly truncate interiorly near tarsal articulation. Tarsomeres ventrally with sparse, short setae, not carinate laterally, with fine sparse punctures dorsally; 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. 1E–G . Habitus: Fig. 1H .

Female unknown.

Diagnosis. Neoserica judsoni Ahrens & Pham , new species differs from N. calva (Frey, 1972) by the straight right paramere and the distinctly smaller eyes.

Etymology. Named after its collector, Judson Linsley Gressitt (1914–1982).

Figures

FIGURE 1. A–D: Neoserica axelkalliesi Ahrens & Pham, new species (holotype); E–H: N. judsoni 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.