Tetraserica quangnam Ahrens, Pacholátko & Pham, 2025

Tetraserica quangnam Ahrens, Pacholátko & Pham View in CoL , sp. nov.

Fig. 5G–K View FIGURE 5

Type material examined. Holotype ♂ “VS1009 / VS1009 Vietnam Quang Nam Pro., Nam Tra My Dist., Ngoc Linh Gingsen sta. 18.v.2023 14°59’10”N, 108°03’08’’E P.V. Pham & G. Sabatinelli Tetraserica spnVi5 / Asia Sericini spec. 1363” ( IBHV). GoogleMaps

Description of the holotype. Length: 11.0 mm; length of elytra: 8.5 mm; maximum width: 6.5 mm. Dorsal surface dark brown and glabrous, labroclypeus, pronotal margins and ventral surface reddish brown, femora and antenna yellow.

Labroclypeus subtrapezoidal, wider than long, widest at base, lateral margins moderately convex and convergent to strongly rounded anterior angles, anterior margin weakly emarginate medially, margins moderately reflexed; surface weakly convex, moderately shiny, finely and densely punctate, glabrous; frontoclypeal suture indistinctly incised, flat and weakly curved medially; ocular canthus short and triangular, impunctate, with a single terminal seta. Smooth area anterior to eye twice as wide as long. Frons dull, with sparse, fine punctures, with two single erect setae beside each eye. Antenna yellowish, with ten antennomeres; club composed of four antennomeres in male, straight, 1.2 times as long as remaining antennomeres combined. Eyes moderately small, ratio of diameter/ interocular width: 0.65. Mentum elevated and slightly flattened anteriorly.

Pronotum moderately wide and convex, widest shortly before base, lateral margins evenly convex, strongly narrowed anteriorly towards sharp and slightly produced anterior angles, posterior angles convex. Anterior margin of pronotum slightly convex, with fine, complete marginal line. Surface finely and densely punctate, except minute setae glabrous, lateral and lateral anterior margins densely setose. Hypomeron not carinate. Scutellum triangular, finely and densely punctate.

Elytra oblong, widest in posterior third, striae distinctly impressed, finely and moderately densely punctate, intervals flat, with fine and almost evenly dense punctures weakly concentrated along striae, with very minute setae in punctures and a very few short setae on odd intervals; epipleural edge robust, ending at convex external apical angle of elytra, epipleura densely setose; apical border with a narrow fringe of microtrichomes (100x).

Ventral surface dull, finely and densely punctate, metasternum sparsely covered with fine, short, or very minute setae; metacoxa glabrous, with a few single setae laterally; abdominal sternites finely and densely punctuate, with a transverse row of coarse punctures, each bearing a robust seta. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.49. Pygidium moderately convex and dull, densely punctate, without smooth midline, almost glabrous, with a few longer setae along apical margin.

Legs wide; femora finely and sparsely punctate; metafemur wide and moderately shiny or dull, anterior margin acute, posterior margin smooth ventrally and only weakly widened in apical half, posterior margin smooth dorsally, with a few short setae basally. Posterior margin of metafemur generally straight or slightly convex. Metatibia short and wide, widest at middle; ratio width/length: 1/2.5; basal group of dorsal spines of metatibia at first third, apical one at two thirds of metatibial length; apex of metatibia strongly truncated ventrally, ventral terminal spine very long and s-shaped, situated subapically at two thirds of metatibial length on ventral margin, ending at the level of distal margin of metatarsomere 1; distal margin extremely deeply truncated ending at the ventral margin at posterior third of metatibial ventral margin. Tarsomeres dorsally smooth, with fine, dense setae ventrally on distal half, neither laterally nor dorsally carinate; metatarsomeres with a strongly serrated ridge ventrally and glabrous; first metatarsomere slightly shorter than following two tarsomeres combined, one third of its length longer than dorsal tibial spine. Protibia short, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Fig. 5I–K View FIGURE 5 . Habitus: Fig. 5G, H View FIGURE 5 . Female unknown.

Diagnosis. Tetraserica quangnam Ahrens, Pacholátko & Pham , sp. nov. is in shape of metatibia similar to Tetraserica bartolozzii Ahrens, 2023 . The new species, however, differs by the less strongly truncated metatibia of which the ventral terminal spine is situated not at middle of the ventral margin but at posterior third of metatibial ventral margin; furthermore, the shape of parameres differs distinctly between the both species: The right paramere is in the new species strongly hooked at apex, while the left parameres is curved evenly ventrally instead of being reflexed dorsally (as in T. bartolozzii ).

Etymology. The new species is named after its occurrence in the Quang Nam province (noun in apposition).