Acromyrmex fracticornis

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil, Paraguay, Uruguay.

Acromyrmex fracticornis constructs conspicuous nest turrets made of interlaced plant fragments. Corsarinsky et al. (2020) asked whether turrets are built by merely piling up nearby materials around the nest entrance, or whether ants incorporate different materials as the turret develops. Their experiments revealed that consolidation of the turret occurred both over time and from its base upwards. Different building behaviors are involved, namely (1) intermeshing grass fragments and twigs around the nest opening, (2) cementing the resulting mesh with soil pellets, and (3) lining the inner gallery wall. Nest turrets do not simply arise by the arbitrary deposition of nearby materials, since workers both selectively incorporate large materials at the beginning, and respond to the developing structure by reinforcing the intermeshed plant fragments over time.

Nomenclature

 *  fracticornis. Atta (Moellerius) fracticornis Forel, 1909a: 257 (w.) PARAGUAY. Fowler, 1988: 286 (m.). Combination in Acromyrmex (Moellerius): Forel, 1913l: 236. Subspecies of landolti and senior synonym of jorgenseni: Gonçalves, 1961: 126; Kempf, 1972a: 16. Revived status as species: Fowler, 1988: 286.
 * jorgenseni. Acromyrmex (Moellerius) fracticornis var. jorgenseni Forel, 1913l: 236 (w.q.) ARGENTINA. Bruch, 1916: 325 (m.). Junior synonym of fracticornis: Gonçalves, 1961: 126.