Key to Aenictus of India

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This key to workers of Indian Aenictus is based on Bharti et al. (2012) as modified by Sahoo et al. (2023).

Note that this key does not include Aenictus kodungallurensis or Aenictus malakkaparensis, both of which were described after Bharti et al.'s key was published.


  • Mandibles narrow, 3- or 4-toothed, and in closed position their inner borders are often (but not always) separated from the anterior clypeal border by a large gap => 2
  • Mandibles broad and triangular; bearing a distinct apical tooth and a preapical tooth, followed by at least 4 or 5 smaller teeth or denticles, the posteriormost of which are much smaller than the apical tooth; mandibular gap lacking => 5


return to couplet #1

  • Anterior clypeal border entire and convex and bearing approximately 6 small but distinct teeth; a small (HW, 0.51–0.53 mm), shining, very hairy brownish yellow species with very short scapes (SI, 66–69) => Aenictus brevicornis
Aenictus brevicornis casent0281955 p 1 high.jpg
  • Anterior clypeal border lacking teeth, and emarginate => 3


return to couplet #2

  • Scapes very short (SI, 58–61); junction of propodeal faces an even convex curve => 4


return to couplet #3

  • Clypeus strongly emarginate; mandibles thick, strongly curved inward; at closure the inner mandibular borders are separated from the anterior clypeal border by a gap as wide as the maximum width of the scape => Aenictus doryloides
  • Clypeus straight or slightly convex; mandibles neither conspicuously thickened or curved inward; in closure the inner mandibular borders either reach the anterior clypeal border or are separated from it by a gap much narrower than in doryloides => Aenictus piercei
Aenictus piercei casent0281961 p 1 high.jpg


return to couplet #1

  • “Typhlatta spots” present; these are a pair of large, pale, circular areas covering most of the posterolateral portions of the head and contrasting sharply with the much darker remainder of the head => 6
  • “Typhlatta spots” absent => 9


return to couplet #5

  • Subpetiolar process prominent and angular => 7
Aenictus gracilis casent0217376 p 1 high.jpg


return to couplet #6

Aenictus laeviceps casent0217377 p 1 high.jpg
  • Seen from the side, the propodeal faces join in a sharp angle => 8


return to couplet #7

  • Pronotal dorsum microreticulate and opaque; a somewhat larger species, HW, 0.79–0.92 mm => Aenictus binghamii
Aenictus binghami casent0217371 p 1 high.jpg
Aenictus fergusoni casent0281962 p 1 high.jpg


return to couplet #5

  • Subpetiolar process large and angulate => 10
  • Subpetiolar process either absent or else merely a low, evenly round lobe => 11


return to couplet #9

  • Pronotum shining, remainder of mesosoma and petiole microreticulate; mandibles with more than 5 denticles => Aenictus peguensis
Aenictus peguensis casent0281968 p 1 high.jpg


return to couplet #9

  • Mesonotum demarcated from mesopleuron by a conspicuous ridge => 12
  • Mesonotum not visibly demarcated from mesopleuron => 13


return to couplet #11

  • Reddish brown; head width 0.84 mm; metanotal impression present; parafrontal ridge about 0.22mm long => Aenictus indicus
Aenictus indicus antweb1008019 h 1 high.jpg
Aenictus indicus antweb1008019 p 1 high.jpg
  • Blackish; head width 0.7–0.74 mm; metanotal impression absent; parafrontal ridge about 0.27 mm long => Aenictus wilsoni
Aenictus wilsoni antweb1008020 h 1 high.jpg
Aenictus wilsoni antweb1008020 p 1 high.jpg


return to couplet #11

  • Anterior clypeal border dentate; small species, HW 0.43-0.53 mm; scapes long, scape index at least 102 and usually much more => 14
  • Anterior clypeal border not dentate; larger species, HW at least 0.57 mm; scapes shorter, scape index not exceeding 102 and usually much less => 15


return to couplet #13

Aenictus wroughtonii casent0907022 h 1 high.jpg
Aenictus wroughtonii casent0907022 p 1 high.jpg
Aenictus sagei casent0281958 h 1 high.jpg
Aenictus sagei casent0281958 p 1 high.jpg


return to couplet #13

  • Occiput constricted behind into narrow but distinct “collar”; propodeal angle (junction of basal and declivitous faces) longer in profile than maximum length of propodeal spiracle, very thin acute, and far overhanging the declivitous face; a large species (HW, 0.78–0.81 mm) with long (SI about 137) => Aenictus dentatus
Aenictus dentatus casent0217375 h 1 high.jpg
Aenictus dentatus casent0217375 p 1 high.jpg
  • Occiput not constricted behind into a large collar; propodeal angle no longer than maximum spiracle width and not overhanging the declivitous face => 16


return to couplet #15

Aenictus aitkenii casent0905981 h 1 high.jpg
Aenictus aitkenii casent0905981 p 1 high.jpg
  • Pronotum mostly smooth and shining => 17


return to couplet #16

  • Longitudinal rugulae present on propodeal dorsum; head shining except for microreticulate band of occiput => Aenictus punensis
Aenictus punensis casent0281959 h 1 high.jpg
Aenictus punensis casent0281959 p 1 high.jpg
  • Longitudinal rugulae lacking on propodeal dorsum; head partly shiny or completely microreticulate => 18


Aenictus pachycerus casent0217379 h 1 high.jpg
Aenictus pachycerus casent0217379 p 1 high.jpg
Sahoo, B., Ramakrishnaiah, S. et al. 2023. A new species of army ant genus Aenictus from India (10.51963@jers.v25i3.2504), Fig. 1.jpg
Sahoo, B., Ramakrishnaiah, S. et al. 2023. A new species of army ant genus Aenictus from India (10.51963@jers.v25i3.2504), Fig. 4.jpg