Trigonopterus rhombiformis Riedel

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

77. Trigonopterus rhombiformis Riedel sp. n.

Diagnostic description.

Holotype, male (Fig. 77a). Length 2.93 mm. Color of antennae ferruginous; legs dark ferruginous; remainder black. Body subrhomboid; in dorsal aspect humeri projecting, with weak constriction between pronotum and elytron; in profile dorsally convex. Rostrum dorsally in basal 1/2 with median and pair of submedian ridges, intervening furrows and anteriorly punctate, with sparse suberect elongate scales; epistome posteriorly with transverse ridge. Pronotum with lateral edges weakly converging, before apex rounded to subapical constriction; disk punctate, forming broad ridge with impunctate median line; in basal 1/2 with pair of subglabrous patches. Elytra with striae marked by weakly impressed lines and rows of fine punctures; intervals with interspersed punctures; along basal margin and swollen humeri with denser, larger punctures. Femora edentate. Metafemur with dorsoposterior edge denticulate; subapically with stridulatory patch. Metatibia in basal 1/3 slightly widened, dorsal edge denticulate. Abdominal ventrites 1-2 concave, subglabrous, with sparse erect subclavate scales; ventrite 5 almost flat, weakly concave, subglabrous. Penis (Fig. 77b) with sides of body subparallel; apex rounded, with sparse setae; apodemes 2.4 × as long as body of penis; transfer apparatus complex, anchor-shaped; ductus ejaculatorius with distinct bulbus.

Material examined.

Holotype (MZB): ARC2795 (GenBank # MK260256), N-Sulawesi Prov., Airmadidi, Gn. Klabat, 01°26.430'N 125°00.622'E, 889 m, sifted, 17-V-2012.

Distribution.

N-Sulawesi Prov. (Mt Klabat). Elevation ca. 890 m.

Biology.

In leaf litter of montane forest.

Etymology.

This epithet is a combination of the Latin nouns rhombus (rhomb), forma (shape) and the 2nd adjectival declension ending -is, and refers to the body shape of this species. A variable adjective.

Notes.

Trigonopterus rhombiformis Riedel, sp. n. was coded as " Trigonopterus sp. 387".