Trigonopterus impressicollis Riedel

Riedel, Alexander & Narakusumo, Raden Pramesa, 2019, One hundred and three new species of Trigonopterus weevils from Sulawesi, ZooKeys 828, pp. 1-153 : 1

31. Trigonopterus impressicollis Riedel sp. n.

Diagnostic description.

Holotype, male (Fig. 31a). Length 2.26 mm. Color of antennae, legs, and elytral humeri ferruginous; remainder black. Body subovate; in dorsal aspect with moderate constriction between pronotum and elytron; in profile dorsally convex. Rostrum dorsally with median carina and pair of submedian ridges; intervening furrows with sparse, erect scales; epistome short, posteriorly with transverse ridge. Pronotum with lateral edges weakly converging, with weak subapical constriction; disk with pair of distinct longitudinal impressions, lined with yellow elongate scales; medially broadly swollen, densely punctate, interspaces subglabrous, with narrow median costa. Elytra sparsely punctate with minute punctures; striae marked by impressed lines; in basal 1/3 and subapically with sparse yellow recumbent scales. Femora dentate, with acute tooth; anteroventral ridge of metafemur crenate. Metafemur with dorsoposterior edge weakly denticulate; subapically with stridulatory patch. Meso- and metatibia subbasally slightly widened, dorsal edge serrate. Metatibia curved. Abdominal ventrites 1-2 concave, subglabrous, sparsely punctate, with few scattered piliform scales; ventrite 5 concave, punctate, with sparse erect setae. Penis (Fig. 31b) with sides of body subparallel; apex subtruncate, laterally with tufts of long curly setae; apodemes 4.0 × as long as body of penis; transfer apparatus flagelliform, 3.5 × longer than body of penis; ductus ejaculatorius with indistinct bulbus. Intraspecific variation. Length 1.90-2.38 mm. Color of elytra ferruginous, partly ferruginous, or black. Female rostrum slender, dorsally in apical 1/2 subglabrous, with submedian row of punctures and with pair of sublateral furrows.

Material examined.

Holotype (MZB): ARC3222 (GenBank # MK260468), S-Sulawesi Prov., Mangkutana, 02°20.203'S 120°46.878'E, 903 m, sifted, 14-V-2013. Paratypes (MZB, SMNK): S-Sulawesi Prov.: 14 exx, ARC3223 (GenBank # MK260472), ARC3224 (GenBank # MK260471), ARC6042 (GenBank # MK260470), ARC6043 (GenBank # MK260469), same data as holotype.

Distribution.

S-Sulawesi Prov. (Mangkutana). Elevation ca. 900 m.

Biology.

In leaf litter of montane forest.

Etymology.

This epithet is an adjectival combination of the Latin participle impressus, -a, -um (imprinted), the noun collum (neck), and the second adjectival declension ending -is, and refers to the pair of impressions on the pronotum.

Notes.

Trigonopterus impressicollis Riedel, sp. n. was coded as " Trigonopterus sp. 491".