Key to subfamilies of the Neotropical region

This key is translated and modified from Baccaro et al (2015) with permission of the authors

1

 * One reduced segment between mesosoma and gaster (petiole). First gaster segment completely joined to the second, or separated by only a slight constriction. In this last case, first gaster segment not clearly reduced .....2
 * Two reduced segments between mesosoma and gaster (petiole and postpetiole). Postpetiole about the same size than petiole or slightly greater, but always much smaller than first gastral segment and separated from it by a deep constriction .....11

2
return to couplet 1
 * Spiracles of the gastral segments 3 to 5 (abdominal segments 5 to 7) not concealed, not covered by the precedent tergite, and visible without stretching the abdomen. Metapleural gland covered dorsally by a long cuticular strip, parallel to the main axis of the body. Helcium sternite big, convex and with its ventral part visible in lateral view. Metatibial gland normally present …..Dorylinae (Key to Neotropical genera)
 * Spiracles of the gastral segments 3 to 5 (abdominal segments 5 to 7) concealed, covered by the precedent tergite, and not visible without stretching the abdomen. Metapleural gland exposed, not covered dorsally by a long cuticular strip. Helcium sternite small, not visible in lateral view. Metatibial gland absent .....3

3
return to couplet 2
 * First and second gastral segment (third and fourth abdominal segment) separated by a slight constriction, if not, mandibles long and linear, strongly curved inwards apically and inserted medially at the anterior cephalic margin. Second gastral segment (fourth abdominal) with or without tergo-sternal fusion. Sting present .....4
 * First and second gastral segment (third and fourth abdominal segment) confluent and not separated by a slight constriction. Mandibles varying, but never long and linear. Second gastral segment (fourth abdominal) never with tergo-sternal fusion, both are separated and can move independently from each other. Sting absent .....10

4
return to couplet 3
 * Mandibles slender and long. Anterior clypeal margin without denticles, with a dense row of hairs. Eyes absent. Second gastral segment (fourth abdominal) without tergo-sternal fusion ….. Martialinae
 * Mandibles varying, but if slender and long then the anterior clypeal margin with denticles. Eyes absent or present. Second gastral segment (fourth abdominal) with tergo-sternal fusion, both are strongly fused and can not move independently from each other .....5

5
return to couplet 4
 * Anterior clypeal margin with a row of denticles. Petiole (second abdominal segment) broadly joined to the gaster (third abdominal segment), without an exposed posterior side ….. Amblyoponinae (Key to Neotropical genera)
 * Anterior clypeal margin without a row of denticles. Petiole (second abdominal segment) joined to the gaster (third abdominal segment), by a deep constriction, leaving the posterior side axposed .....6

6
return to couplet 5
 * In profile view, metapleural gland a slit longitudinal and curved, delimited in its inferior side by a flange of cuticle, leaving the orifice oriented dorsally ….. Ectatomminae (Key to Neotropical genera)
 * In profile view, metapleural gland ovoid or circular, opening laterally or posteriorly, without cuticular flange .....7

7
return to couplet 6
 * Promesonotal suture present, flexible and well developed on the mesosoma's dorsum, pronotum and mesonotum can move independently .....8
 * Promesonotal suture present or absent,, if present, fused., pronotum and mesonotum can not move independently .....9

8
return to couplet 7
 * Cephalic dorsum with a median longitudinal carina extending from the anterior clypeal margin to the vertex. Anterior clypeal margin with an extension forming a lamella ….. Heteroponerinae (Key to Neotropical genera)
 * Cephalic dorsum without a median longitudinal carina. Anterior clypeal margin without an extension forming a lamella …..Ponerinae

9
return to couplet 7
 * Antennal sockets mostly or totally exposed, located close to the anterior margin of the head. Pretarsal claws simple, without preapical teeth. Antennal scrobes absent. Small to minute ants …..Proceratiinae (Key to Neotropical genera)
 * Antennal sockets concealed by the frontal lobes, located far from the anterior margin of the head. Pretarsal claws with preapical teeth. Antennal scrobes present …..Paraponerinae

10
return to couplet 3
 * Propodeum mostly often rounded or slightly angled in profile view, rarely with tubercles, lamellae or spines. Fifth gastral tergite big and visible. Gastral apex with circular to semicircular acidopore present, projecting from the hypopigium as a tubule surrounded by quetae, sometime by the pygidium itself ….. Formicinae.
 * Propodeum sometimes notably angled in profile view, with conspicuous tubercles, lamellae or spines (particularly in species >5 mm long). Fifth gastral tergite usually small and inconspicuous. Gastral apex without acidopore, but the pygidium and hypopigium forming a transversal slit….. Dolichoderinae.

11
return to couplet 1
 * Very big eyes, occupying at least one half of the lateral side of the head. Ocelli present ….. Pseudomyrmecinae (Key to Neotropical genera)
 * Smaller eyes, never occupying at least one half of the lateral side of the head .....12

12
return to couplet 11
 * Frontal lobes well developed, and sometimes notably expanded, covering totally or partially the antennal insertions. If not, the eyes developed and formed by more than one ommatidium. Postpetiole (third abdominal segment) without tergosternal fusion. Metatibial gland absent. Spiracles of gastral segments two to four not exposed, cover by precedent tergite .....13
 * Frontal lobes vestigial or absent, leaving the antennal insertions exposed in frontal view. Eyes formed by one ommatidium, vestigial, or absent. Postpetiole (third abdominal segment) with tergosternal fusion. Metatibial gland present. Spiracles of gastral segments two to four exposed and visible without stretching the abdomen ….. Dorylinae

13

 * Eyes located at the apex of the antennal scrobe. Antennae with seven segments ….. Agroecomyrmecinae
 * Eyes located otherwise. If the eyes are located at the apex of the antennal scrobe then antennae with more than seven segments Myrmicinae