Hexarhopalus (Hexarhopalus) kaminskii, Purchart, 2025

Hexarhopalus (Hexarhopalus) kaminskii sp. nov.

( Figs 2a–l View FIGURE 2 )

Type material. Holotype ♂ ( NMPC): {white, printed} VIETNAM north / Hà Giang prov., vii.2024 / Thành Ph ố Hà Giang / local collector leg . Paratypes. (4 ♂ + 4 ♀ LPCB, 1 ♂ MKCP) : same data as the holotype .

Differential diagnosis. Due to its black body and large confluent tubercles in elytral interstriae the new species resembles H. higurashii Masumoto & Akita, 2022 ( Laos) and H. julioi Jang & Chen, 2024 ( China). Hexarhopalus higurashii differs from the new species by tubercles in elytral interstriae arranged regularly in rows, different pronotal surface being more rugose and by having more or less shiny head (compare Figs 1a, d View FIGURE 1 with Fig. 3 View FIGURE 3 in Masumoto & Akita 2022). Hexarhopalus julioi can be distinguished by differently arranged rugosity on the pronotal surface, by distinct oblique indentation in posterior pronotal angles (indistinct in the new species) and mainly by a roughly punctured vertex (compare Figs 1d, e View FIGURE 1 with Figs 2a, b View FIGURE 2 in Jang et al. 2022). It is also similar to H. ruzzieri sp. nov., H. tuberculatus (Pic, 1928) ( Figs 4f, g View FIGURE 4 ), H. tuberculipennis Kaszab, 1960 ( Figs 6h, p View FIGURE 6 ; for habitus see Fig. 14 in Kaszab 1960) and H. loebli Bečvář & Purchart, 2008 ( Figs 6e, i View FIGURE 6 ; for habitus see Fig. 4 View FIGURE 4 in Bečvář & Purchart 2008). All these species, however, differ from the new species by having their tubercles in elytral rows isolated and well separated, whereas they are confluent in the new species.

Description. Size of the holotype 11.6 × 6.5 mm. Body black, elongate oval, strongly convex ( Figs 1a–c View FIGURE 1 ).

Head narrower than pronotum in ratio 1:1.5 ( Figs 1a, d View FIGURE 1 ). Whole surface shagreened, strongly matt; with fine very short (as long as one eye facet) yellow hairs in sparse and extremely shallow punctures. Frontoclypeal suture weakly marked, complete. Ocular sulcus moderately deep. Distance between eyes 2× wider than their transverse diameter (DV). Labrum shiny, strongly transverse, flat, apically with long yellow setae. Antenna shiny, 1.28× longer than pronotum, covered with yellow adherent hairs. Palpomeres shiny, apical maxillary palpomere securiform. Mentum with well visible lateral wings, middle part of mentum with two deep longitudinal grooves.

Pronotum coarsely sculptured, longer little than broad, widest before middle, sides rounded in apical third quarter, straight in basal fourth ( Figs 1a, d View FIGURE 1 ), PW:PL ratio is 1:1.05. Pronotal margins completely bordered but obliterated in middle of anterior border. The latter is straight, basal margin rounded in middle. Oblique indentation in posterior angles shallow but well visible ( Fig. 1e View FIGURE 1 ). Dorsal surface shagreened, strongly matt, covered with irregular shiny sculptures, with exception of midlongitudinal groove which is lacking any sculptures or rugosities. Both sides of pronotum with large swelling situated antero-laterally. Prothoracic hypomeron shagreened, smooth, glabrous.

Elytra ovate, robustly convex, 1.48× longer than its width and 2.23× longer and 1.44× wider than pronotum, broadest behind midlength (DV), highest at or promptly behind midlength (LV). Basal margin slightly raised but not carinated. Elytral surface shagreened with exception of tubercles and large protuberances situated densely in slightly convex elytral interstriae. Small isolated tubercles situated mostly along elytral suture and at apical declivity of elytra; larger tubercles situated on steep sides of elytra. Large longitudinal or transversal protuberances situated mainly on disc of elytra ( Fig. 1a View FIGURE 1 ). Apterous. Scutellum narrowly triangular ( Fig. 1d View FIGURE 1 ).

Prosternum strongly shagreened, matt. Prosternal process steeply inclined anteriorly, with shallow grove between coxae, almost vertically declivous behind coxae, apical part horizontal, flat, apex rounded. Mesoventrite coarse in apical half, shagreened, with shiny midlongitudinal carina in middle, posterior part steeply inclined towards mesocoxae, shagreened, matt.Metaventrite narrow (narrower than mesocoxa), shagreened, matt.Abdominal ventrites glabrous, covered densely with very shallow punctures; abdominal ventrites I–III shagreened, matt; abdominal ventrites IV–V shiny ( Fig. 1b View FIGURE 1 ).

Legs shiny, densely punctate; protibiae distinctly curved in both sexes.

Aedeagus, spiculum gastrale, male inner sternite VIII, and male inner tergites VII and VIII are shown in Figs 1f–l View FIGURE 1 .

Variability of size: 14.9–17.3 × 6.2–7.2 mm.

Etymology. Named in honour of my colleague and friend Marcin Jan Kamiński ( Poland), a prominent expert on Tenebrionidae .