Key to genera of the subtribe Metrioxenina

1. Femora with tooth. Metatibiae in males strongly curved Metrioxena

– Femora without tooth 2

2. Eyes finely faceted. Rostrum lacking adpressed setae ventrally. Metatibiae in males Sumatraxena gen. nov. strongly curved. Antennae almost reaching base of pronotum. Head behind eyes with weak constriction

– Eyes coarsely faceted. Rostrum with adpressed setae ventrally. Metatibiae in males Sundaxena gen. nov. straight. Antennae reaching middle of pronotum. Head behind eyes with stark constriction