Key to the species of Oncotympana

1 Male abdomen obconical, about as long as or slightly longer than wide .................................................................... 2

- Male abdomen cylindrical, much longer than wide.................................................................................................... 4

2 Timbal cover barely prominent laterally, making male abdominal tergite 2 including timbal covers about as wide as or slightly wider than tergite 3; male operculum roundish .......................................................................................... 3

- Timbal cover prominent laterally, making male abdominal tergite 2 including timbal covers much wider than tergite 3; male operculum obliquely rectangular............................................................................................... undescribed sp.

3 Body smaller, about 18.0 mm long; forewing basal vein of apical cell 1 more than half as long as longitudinal vein of apical cell 1; timbal cover without any marks .......................................................................................... pallidiventris

- Body larger, about 28.7 mm long; forewing basal vein of apical cell 1 about one-third as long as longitudinal vein of apical cell 1; timbal cover with broad fuscous fascia along posterior margin ..................................... grandis sp. nov.

4 Timbal covers widely separated with gap between them about half as wide as timbal cover..................................... 5

- Timbal covers narrowly separated with gap between them less than one-third as wide as timbal cover.... nigristigma

5 Body smaller, 16.0–21.0 mm long; pronotum with just one, fused, medial longitudinal black fascia; forewing costal vein distinctly enlarged near node to form protuberance; timbal cover margined with fuscous ................ viridicincta

- Body larger, about 23.4–25.3 mm long; pronotum with pair of medial longitudinal black fasciae; forewing costal vein slightly enlarged near node; timbal cover without any marks ............................................................................. 6

6 Medial longitudinal fascia on mesonotum broad, broader than median breadth of sublateral marks on lateral sigilla; both uncal lobes forming heart shape with their inner margins, which is wider than long; uncal lobes with apex directed toward center in ventral view................................................................................................ simonae sp. nov.

- Medial longitudinal fascia on mesonotum narrow, narrower than sublateral marks on lateral sigilla; both uncal lobes forming heart shape with their inner margins, which is longer than wide; uncal lobes with apex directed downward (anteriad) or laterad in ventral view ............................................................................................................................. 7

7 Forewing short and broad (ratio of forewing length to forewing width approximately 2.83); uncal lobes with truncate and laterally acute apex directed downward in ventral view .................................................................. brevis sp. nov.

- Forewing comparatively long and slender (ratio of forewing length to forewing width approximately 3.01); uncal lobes with triangular apex directed laterad in ventral view .................................................................. undata sp. nov.