Trigonopterus siamensis, Riedel, 2022

Riedel, Alexander, 2022, Nine new species of Trigonopterus Fauvel (Coleoptera, Curculionidae) from Sundaland, ZooKeys 1124, pp. 109-130 : 109

8. Trigonopterus siamensis sp. nov.

Figs 8 , 10

Material examined.

Holotype (SMNS): ARC7266 (GenBank # OP078707 ), Thailand, Ko Chang , Westseite, 1999.

Diagnostic description.

Holotype, male (Fig. 8a ). Length 3.19 mm. Color black except antennae light ferruginous, legs dark ferruginous. Body in dorsal aspect subrhomboid, with marked constriction between pronotum and elytron; profile dorsally convex. Rostrum with median and pair of submedian ridges; intervening furrows with sparse rows of suberect, clavate scales; epistome with transverse, angulate ridge; forehead in profile with weak subangulate knob. Pronotum with indistinct subapical constriction; disk densely coarsely punctate, interspaces reticulate, weakly microreticulate; each puncture containing small seta. Elytra with humeri swollen, laterally subangularly projecting, coarsely punctate; striae 1-5 distinct, deeply impressed, each with row of coarse punctures and sparse row of suberect scales; intervals costate, microreticulate; sutural interval with row of small punctures; interval 2 almost impunctate; intervals 3-5 with rows of coarse punctures; laterad coarse punctation confused. Metafemur with dorsoposterior edge denticulate; subapically with stridulatory patch. Abdominal ventrites 1-2 forming common cavity, at middle flat, subglabrous, with sparse erect scales; laterally with distinct rim; lateral rim of abdominal ventrite 2 in profile projecting dentiform; abdominal ventrite 5 flat, coarsely punctate-foveate, with sparse erect scales. Penis (Fig. 8b ) with sides of body subparallel; apex subangulate; transfer apparatus flagelliform, ca. 3.2 × as long as body; apodemes 3.9 × as long as body; ductus ejaculatorius without bulbus.

Distribution.

Thailand (Ko Chang Is.).

Etymology.

This epithet is a Latinized adjective based on Siam, the former name of Thailand.

Notes.

Trigonopterus siamensis sp. nov. is coded as " Trigonopterus sp. 1243". This species belongs to the T. trigonopterus group. It is related to T. singaporensis sp. nov., from which it can be distinguished by its elytral intervals 3-5 each with a row of coarse punctures and 18.1% p-distance of its cox1 sequence. It would be important to confirm the locality of this species by additional records.

Figures

Figure 8. Trigonopterus siamensis sp. nov., holotype a habitus b penis.

Figure 10. Map of the new Trigonopterus species of the T. trigonopterus group across the Sundaland area. Prepared using GeoMapApp (www. geomapapp. org;; Ryan et al. 2009); azure = T. grimmi sp. nov., yellow = T. siamensis sp. nov., red = " T. singaporensis sp. nov., magenta = T. trigonopterus Riedel.