Key to Vietnamese genera of the subfamily Amblyoponinae based on the worker caste

1 Petiole narrowly attached to abdominal segment III (gastral segment I); abdominal segment III above helcium with free ante- rior face (Fig. 9); frontal lobe completely absent, thus antennal socket in full-face view fully exposed (Fig. 10).. Opamyrma

- Petiole broadly attached to abdominal segment III; abdominal segment III above helcium without a conspicuous free anterior face (Fig. 11); frontal lobe present, thus antennal socket in full-face view at least partly concealed (Fig.12)............... 2

2 Mandible elongate-triangular, armed with 3 teeth (Fig. 13); in closed position inner margin of mandibles not forming a con- spicuous gap against the anterior clypeal margin..................................................... Prionopelta

- Mandible linear, armed with more than 3 teeth (Figs. 14, 15, 16); in closed position inner margin of mandibles separated from anterior clypeal margin by a large gap..................................................................... 3

3 Apex of mandible round, with minute teeth (Fig. 16); body covered with spatulate setae (Fig. 17)............... Mystrium

- Apex of mandible with distinct apical tooth/teeth (Figs. 14, 15); body without spatulate setae (Fig. 18).................. 4

4 A few apical segments of antenna distinctly flattened (Figs. 19, 20)..................................... Myopopone

- All of antennal segments terete, not flattened (Figs. 21, 22).......................................... Stigmatomma