Tetraserica guidosabatinellii Ahrens, Pacholátko & Pham, 2025

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

Fig. 4H–L View FIGURE 4

Type material examined. Holotype ♂ “VS1047 / VS1047 Vietnam Kon Tum Pro., Kon Plong Dist., near Giraffe tree 15.v.2023 14°43’50”N, 108°21’41’’E P.V. Pham & G. Sabatinelli Tetraserica spnVi10 / Asia Sericini spec. 1362” ( IBHV) GoogleMaps . Paratypes: 1 ♂ “VS1053 / VS1053 Vietnam Kon Tum Pro., Kon Plong Dist., near Giraffe tree 15.v.2023 14°43’50”N, 108°21’41’’E P.V. Pham & G. Sabatinelli Tetraserica spnVi10” ( ZFMK) GoogleMaps , 1 ♂ “VS1068 / VS1068 Vietnam Kon Tum Pro., Kon Plong Dist., Thach Nham Forest Stat. 3 13.v.2023 14°42’13”N, 108°21’21’’E P.V. Pham & G. Sabatinelli Tetraserica spnVi9” ( IBHV) GoogleMaps .

Description of the holotype. Length: 11.0 mm; length of elytra: 8.4 mm; maximum width: 6.8 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, 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 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: 1/1.65. Pygidium strongly convex in apical half 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 small, sharp tooth at the middle and few short setae basally. 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 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. 4J–L View FIGURE 4 . Habitus: Fig. 4H, I View FIGURE 4 . Female unknown.

Variation. Length: 10.5–11.2 mm; length of elytra: 8.2–8.4 mm; maximum width: 6.7–6.8 mm.

Diagnosis. Tetraserica guidosabatinellii Ahrens, Pacholátko & Pham , sp. nov. is in shape of aedeagus most similar to Tetraserica miniatula (Moser, 1915) and T. giulianae Fabrizi, Dalstein & Ahrens, 2019 . The new species differs by the much shorter right paramere, of which both branches are of the same length. Furthermore, T. guidosabatinellii Ahrens, Pacholátko & Pham , sp. nov. has the dorsal lobe of the left paramere strongly and abruptly double bent at apex, the latter is slightly shorter than the ventral lobe of the left paramere.

Etymology. The new species is named after our colleague and chafer specialist, who was one of the collectors of this new species, Guido Sabatinelli (noun in genitive singular).