Holotype, male (Fig. 88a). Length 2.70 mm. Color of head, legs, and sutural interval of elytra ferruginous, remainder black. Body subhexagonal; in dorsal aspect with marked constriction between pronotum and elytron; with distinct constriction in profile. Rostrum with median ridge and pair of submedian ridges, intervening furrows each with row of erect scales; epistome with transverse, angulate ridge forming median denticle. Pronotum anterolaterally angularly projecting; with distinct subapical constriction; disk rugose-punctate, interspaces microreticulate; punctures each with small suberect scale; with glabrous median ridge. Elytra with striae deeply impressed, each with row elongate suberect scales; intervals costate to carinate, with weak transverse wrinkles, microreticulate; interval 7 swollen subapically, laterally projecting. Femora edentate, with crenulate anteroventral ridge. Metafemur subapically with stridulatory patch and transverse rows of denticles. Abdominal ventrites 1–2 with common concavity, each sublaterally with pair of knobs; in profile ventrite 2 projecting angularly; ventrite 5 basally swollen, medially with trapezoid, shallow, polished impression. Penis (Fig. 88b) with sides of body subparallel, apex medially with rounded extension; with ca. 4 symmetrical pairs of elongate endophallic sclerites; transfer apparatus flagelliform, ca. 1.5 × as long as body; apodemes 2.0 × as long as body; ductus ejaculatorius without bulbus. Intraspecific variation. Length 2.12–2.83 mm. Color of body black, partly or fully ferruginous. Female rostrum dorsally with pairs of lateral and submedian furrows; epistome simple. Female abdominal ventrites 1–2 with concavity shallower, sublaterally without knobs; female abdominal ventrite 5 weakly convex, almost flat, with coarse punctures.

Holotype (MZB): ARC1536 (EMBL # LM655634), Banten Prov., Pandegelang, Mt. Karang, sample 3, S06°17.110', E106°03.263', 1145 m, 20-III-2010. Paratypes (ARC, MZB, SMNK, ZSM): 5 exx, ARC0102, W-Java Prov., Mt. Halimun N.P., Citalahab, S06°44.503', E106°31.550', 1150 m, 20-21-IX-2004; 9 exx, W-Java Prov., Mt. Halimun N.P., Citalahab, sample 1A, S06°44.503', E106°31.55', 1200 m, 11-IX-2005; 5 exx, W-Java Prov., Mt. Halimun N.P., Citalahab, sample 1, S06°44.423', E106°31.738', 1100 m, 12-IX-2005; 29 exx, ARC0208 (EMBL # LM655430), ARC0209 (EMBL # LM655431), ARC0210 (EMBL # LM655432), ARC0392, W-Java Prov., Mt. Halimun N.P., Citalahab, sample 2, S06°44.503', E106°31.550', 1200 m, 12-IX-2005; 9 exx, W-Java Prov., N Ciptarasa, sample 2, S06°50.045', E106°30.218', 1050 m, 19-IX-2005; 6 exx, ARC0189 (EMBL # LM655413), W-Java Prov., N Ciptarasa, sample 3, S06°49.867', E106°30.085', 1100 m, 19-IX-2005; 3 exx, W-Java Prov., N Ciptarasa, sample 4, S06°49.802', E106°30.020', 1150 m, 19-IX-2005; 3 exx, ARC1537 (EMBL # LM655635), ARC1539 (EMBL # LM655637), same data as holotype; 1 ex, Banten Prov., Pandegelang, Mt. Karang, sample 2, S06°17.266', E106°03.262', 1025 m, 20-III-2010; 1 ex, Banten Prov., Pandegelang, Mt. Karang, sample 3, S06°17.110', E106°03.263', 1145 m, 26-IV-2010; 1 ex, ARC1538 (EMBL # LM655636), Banten Prov., Pandegelang, Mt. Karang, sample 8, 1100 m, 26-IV-2010.

Banten Prov. (Mt. Karang), W-Java Prov. (Mt. Halimun N.P.). Elevation: 1100–1200 m.

This epithet is based on the type locality which is situated just east of the Sunda Strait; it is also part of the Sunda region of Java.

Trigonopterus sundaicus Riedel, sp. n. was coded as “Trigonopterus sp. 296”.