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

The key includes Sphinctomyrmex, which is known from Thailand (Jaitrong Weeyawat, pers. comm.), Myanmar and India, but not yet from Vietnam.

1 Abdomen without a strong girdling constriction between segments III and IV (Fig. 1). Cerapachys (part: C. sexspinus group)

- Abdomen with a strong girdling constriction between segments III and IV (Fig. 2)................................. 2

2 Strong girdling constrictions present between abdominal segments III and IV, IV and V, V and VI (Fig. 76). Sphinctomyrmex

- Abdominal segments IV, V and VI without girdling constrictions separating them (Fig. 3)............................ 3

3 Frontal lobes relatively broadly separated from each other by median portion of clypeus (Fig. 77); antennal socket in full-face view partly concealed by frontal lobe; tibial spurs absent from middle legs (at most a setiform vestige may remain that cannot be distinguished by light microscopy from other setae at tibial apex)..................................... Simopone

- Frontal lobes very narrowly separated from each other by a longitudinal strip of median portion of clypeus (Fig. 4); antennal socket in full-face view almost completely exposed; one or two tibial spurs present on middle legs (Fig. 5)...... Cerapachys