Holotype, male (Fig. 96a). Length 2.88 mm. Color of antennae light ferruginous, legs and head dark ferruginous, remainder black. Body elongate; in dorsal aspect with marked constriction between pronotum and elytron; in profile dorsally without constriction. Rostrum dorsally microreticulate; in basal half with median carina terminating on forehead; with pair of submedian ridges; intervening furrows each with row of punctures and erect scales; epistome with transverse, angulate ridge forming distinct median denticle. Pronotum anterolaterally subangularly projecting; without distinct subapical constriction; disk coarsely punctate-reticulate; each puncture containing small recumbent scale; with median glabrous wrinkle. Elytra with striae deeply impressed; each with row of narrow subrecumbent scales; intervals weakly costate, basally with row of small punctures; basally punctation confused; interval 7 swollen subapically, laterally weakly projecting; sutural interval swollen at apex, protruding. Femora edentate. Metafemur subapically with stridulatory patch and transverse row of denticles. Abdominal ventrite 5 with broadly impressed, shallow pit. Penis (Fig. 96b); sides of body subparallel; apex with median, acute triangular extension; transfer apparatus small; apodemes 2.5 × as long as body; ductus ejaculatorius without bulbus. Intraspecific variation. Length 2.58–3.05 mm. Color of body black, dark ferruginous, or light ferruginous. Female rostrum dorsally with median and pair of submedian costae glabrous; intervening furrows each with row of punctures bearing small scales or scales partly abraded; epistome simple. Elytra with scales long, suberect, or short, subrecumbent. Female abdominal ventrite 5 flat.

Holotype (MZB): ARC1540 (EMBL # LM655638), Java, Banten Prov., Ujung Kulon N.P., Tama Jaya, Mt. Honje, sample 5, S06°46.241', E105°31.542', 260 m, 24-IV-2010 (MZB). Paratypes (MZB, SMNK, ZSM): Java, Banten Prov., Ujung Kulon N.P., Tama Jaya, Mt. Honje: 35 exx, ARC1541 (EMBL # LM655639), same data as holotype; 23 exx, ARC1545 (EMBL # LM655643), ARC1546 (EMBL # LM655644), sample 4, S06°46.141', E105°31.649', 395 m, 23-IV-2010; 55 exx, sample 4, S06°46.141', E105°31.649', 395 m, 24-IV-2010; 24 exx, sample 6, S06°46.206', E105°31.592', 305 m, 24-IV-2010.

Banten Prov. (Ujung Kulon N.P.). Elevation: 260–395 m.

This epithet is based on the type locality.

Trigonopterus ujungkulonensis Riedel, sp. n. was coded as “Trigonopterus sp. 318”.