1	Body in dorsal aspect with marked constriction between pronotum and elytron. Pronotum in basal half with pair of sublateral, kidney-shaped impressions (Fig. 12a)	Trigonopterus baliensis Riedel, sp. n.
1'	Body subovate, in dorsal aspect with weak constriction between pronotum and elytron. Pronotum without pair of distinct sublateral impressions	2
2	Profile with distinct constriction between pronotum and elytron. Pronotum (Figs 55a, 68a) coarsely sculptured with irregular ridges and tubercles	Trigonopterus rugosus Riedel, sp. n. and Trigonopterus pararugosus Riedel, sp. n.
2'	Profile dorsally convex. Pronotum coarsely punctate, reticulate	3
3 (2')	Elytral intervals (Figs 43a, 49a) weakly costate or flat	4
3'	Elytral intervals (Figs 13a, 42a, 91a) dorsally markedly costate	5
4 (3)	Median rod of transfer apparatus thick, straight, 2.0 × as long as body of penis (Fig. 43b)	Trigonopterus klatakanensis Riedel, sp. n.
4'	Median rod of transfer apparatus flagelliform, forming almost full coil, ca 2.7 × as long as body of penis (Fig. 49b)	Trigonopterus mesehensis Riedel, sp. n.
5 (3')	Median rod of male transfer apparatus thin, shorter (1.4 × as long as body of penis), projecting basad (Fig. 13b)	Trigonopterus batukarensis Riedel, sp. n.
5'	Median rod of male transfer apparatus thick, longer (1.6–1.7 × as long as body of penis), projecting basad further than apicad (Figs 42b, 91b)	6
6 (5')	Body of penis (Fig. 42b) with sides subparallel, before apex weakly converging in straight line	Trigonopterus kintamanensis Riedel, sp. n.
6'	Body of penis (Fig. 91b) with shallow constriction at middle, before apex sides slightly swollen	Trigonopterus telagensis Riedel, sp. n.