Key to Eutetramorium group genera

This key to genera is based on: Bolton, B. & Fisher, B.L. 2014. The Madagascan endemic myrmicine ants related to Eutetramorium (Hymenoptera: Formicidae): taxonomy of the genera Eutetramorium Emery, Malagidris nom. n., Myrmisaraka gen. n., Royidris gen. n., and Vitsika gen. n. Zootaxa 3791:1–99. doi:10.11646/zootaxa.3791.1.1

1

 * Anterior clypeal margin with a triangular tooth or prominence at its midpoint. Palp formula 4,3 or 4,2. Antennal socket and torulus within, and surrounded by, a depressed antennal fossa; anterior margin of the fossa is formed by the posterior surface of the lateral portion of the clypeus, which is raised into a ridge or shield-wall in front of the antennal socket . . . Eutetramorium


 * Anterior clypeal margin rounded or notched at its midpoint, without a triangular tooth or prominence. Palp formula 5,3. Anten¬nal socket and torulus not within a depressed antennal fossa; posterior surface of the lateral portion of the clypeus not raised into a ridge or shield-wall in front of the antennal socket . . . . . 2

2
return to couplet #1
 * Frontal carinae extend to close to the posterior margin of the head and form the upper margins of antennal scrobes . . . . . Vitsika


 * Frontal carinae restricted to frontal lobes; antennal scrobes absent . . . . . 3

3
return to couplet #2
 * Propodeum unarmed. Mandible with 5 teeth . . . . . Royidris''


 * Propodeum bispinose. Mandible with 8–13 teeth . . . . . 4

4
return to couplet #3
 * Anterior clypeal margin with a small median notch, usually with a pair of short, slender setae, one on each side of the midpoint within the notch. Eye relatively larger, EL/HW 0.30–0.35; in full-face view eyes located at about the midlength of the side of the head capsule. Propodeal dorsum with > 2 pairs of setae; dorsal (outer) surface of metatibia with standing setae present. Antennal club of 3 to 5 segments . . . . . Myrmisaraka


 * Anterior clypeal margin without a median notch, with a single, unpaired, stout seta at the midpoint of the margin. Eye rela¬tively smaller, EL/HW 0.24–0.30; in full-face view eyes obviously located in front of the midlength of the head capsule. Prop¬odeal dorsum with 0–2 pairs of setae; dorsal (outer) surface of metatibia without standing setae present. Antennal club of 3 segments . . . . . Malagidris