Key to Aenictus minutulus group species

The following worker key is based on Jaitrong & Hashimoto (2012) as modified by Wong & Guénard (2016)

You might be interested in
 * Aenictus species groups (diagnoses)
 * Key to Aenictus species groups
 * The Aenictus genus page.

1

 * Promesonotum in profile with clearly convex dorsal outline; propodeum dorsally extremely lower than promesonotum . . . . . 2
 * Mesosoma dorsally almost flat or feebly convex . . . . . 4

2
return to couplet #1
 * Declivity of propodeum shallowly concave, encircled with a distinct rim (Borneo and Java) . . . A. sp. 56 of WJT
 * Declivity of propodeum with lateral carinae, but not demarcated basally by a transverse carina . . . . . 3

3
return to couplet #2
 * In full-face view posterior margin of head convex; propodeal junction angulated, right-angled; larger species (TL 2.95–3.15mm; HW 0.52–0.58mm) (Vietnam and Myanmar) . . . . . Aenictus peguensis
 * In full-face view posterior margin of head almost straight or feebly concave; propodeal junction roundly angulated; smaller species (TL 2.10–2.15mm; HW 0.48–0.50mm) (Borneo) . . . . . Aenictus subterraneus

4
return to couplet #1
 * Basal margin of mandible with 1–2 small denticles next to large basal tooth and followed by a larger denticle; antennal scape relatively short (SI 63–64) (N. Vietnam) . . . . . Aenictus minimus
 * Basal margin of mandible with 3–5 denticles that gradually reduce in size toward base of mandible; antennal scape relatively long (SI 67–72) . . . . . 5

5
return to couplet #4
 * Head square-shaped and almost as wide as long (CI 91–96); antennal scape relatively short (SI 61–64); polymorphic worker caste with largest individuals exceeding 3.10 mm in TL (Singapore) . . . . . . . Aenictus seletarius
 * Head longer than wide (CI < 90); antennal scape relatively long (SI 67–72); relatively smaller species (TL < 2.60 mm) . . . . . 6

6
return to couplet #5
 * Metapleural gland bulla relatively large; distance between propodeal spiracle and metapleural gland bulla shorter than or almost as long as spiracular diameter (Vietnam and Thailand) . . . . . Aenictus changmaianus
 * Metapleural gland bulla relatively small; distance between propodeal spiracle and metapleural gland bulla clearly longer than spiracular diameter (Sumatra and Java) . . . . . Aenictus minutulus