Tetraserica similis Ahrens, Pacholátko & Pham, 2025

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

Fig. 1A–E View FIGURE 1

Type material examined. Holotype ♂ “ LAOS, 1.–9.ν.1999, Louangphrabang 20°33-4’N 102°14’E Ban Song Cha ( 5km W), 1200m, Vit Kubáň leg. / 1372 Sericini Asia spec.” ( ZFMK) . Paratypes: 11 ♂♂, 2 ♀♀ “ LAOS, 1.–9.ν. 1999, Louangphrabang 20°33-4’N 102°14’E Ban Song Cha ( 5km W), 1200m, Vit Kubán leg.” ( ZFMK) , 1♂ “NW THAILAND MAE HONG SON 28.4.– 3.5.1992 leg. P. Pacholatko / 1380 Sericini Asia spec.” ( ZFMK) .

Description of holotype. Length: 8.9 mm; length of elytra: 6.5 mm; maximum width: 5.6 mm. Dorsal surface dark brown and glabrous, frons and pronotum with weak greenish shine, labroclypeus, ventral surface and legs reddish brown, 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, slightly longer than remaining antennomeres combined. Eyes moderately small, ratio of diameter/interocular width: 0.59. 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 sparsely 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: 1/1.69. Pygidium moderately convex in apical half and dull, densely punctate, without smooth midline, almost glabrous, without longer setae along apical margin.

Legs wide; femora finely and sparsely punctate; metafemur wide and moderately shiny, anterior margin acute, posterior margin smooth ventrally and only weakly widened in apical half, posterior margin smooth dorsally, with a small, convex extension at basal third and glabrous. Metatibia moderately short and wide, widest at middle; ratio width/length: 1/2.9; basal group of dorsal spines of metatibia at first third, apical one at two thirds of metatibial length; distal margin not truncated, terminal spines of normal length. 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 almost as long as following two tarsomeres combined, a quarter 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. 1A–C View FIGURE 1 . Habitus: Fig. 1D, E View FIGURE 1 .

Variation. Length: 8.9–10.3 mm; length of elytra: 6.5–7.1 mm; maximum width: 5.6–5.7 mm. Female: antennal club in female composed of three antennomeres, distinctly shorter than the remaining antennomeres combined.

Diagnosis. Tetraserica similis Ahrens, Pacholátko & Pham , sp. nov. differs from the very similar T.pingjiangensis Liu, Fabrizi, Bai, Yang & Ahrens, 2014 by the mesally extremely widened left paramere which has a large triangular extension on its mesodorsal margin (lateral view).

Etymology. The name of the new species is derived from the Latin adjective similis (similar), with reference to its strong resemblance with T. pingjiangensis .