Key to the known species of Microlarnaca

1 Processes of male ninth abdominal tergite long with apices obviously spiral-curved, apices of processes of tenth abdominal tergite hook shaped; female subgenital plate with posterior margin obtuse angular concave, the lateral lobes triangular................................................................................................. M. fansipan

- Processes of male ninth abdominal tergite short with apices almost straight, apices of processes of tenth abdominal tergite indistinctly hooked; female subgenital plate with posterior margin obtusely rounded........................ M. dicrana