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

References

• Jaitrong, W. & Hashimoto, Y. 2012. Revision of the Aenictus minutulus species group (Hymenoptera Formicidae Aenictinae) from Southeast Asia. Zootaxa 3426, 29-44.
• Wong, M.K.L., Guénard, B. 2016. Aenictus seletarius, a new species of hypogaeic army ant from Singapore, with an updated key to the Aenictus minutulus species group (Hymenoptera: Formicidae: Dorylinae) from Southeast Asia. Annales Zoologici (Warsaw) 66(1):35-42 (doi:10.3161/00034541ANZ2016.66.1.002).