Ectatomma brunneum

Koch et al. (2018) sampled this species in Caryocar barsiliense trees, in southeastern Brazil cerrado, as part of a study examining species interactions in ant-plants.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Panama, Paraguay, Peru, Suriname.

Biology
Bernardia et al (2017) examined the components and variability of E. brunneum sting venom in workers. The venom primarily consisted of proteins and peptides. Workers were sampled across a range of habitats and the venom composition varied with environment, apparently due to their diet.

Dambros et al. (2018) - Ectatomma brunneum was collected via arboreal fogging in an inundated northern Pantanal (Mato Grasso, Brazil) cambarazal forest. The seasonally flooded forest was dominated by Vochysia divergens Pohl. (Vochysiaceae), regionally known as cambará, a tree species considered invasive to the Pantanal’s natural fields.

Passos and Leal (2019) - This species was found attending extrafloral nectaries of the plant Turnera subulata in northeastern Brazil Caatinga vegetation.  Ectatomma brunneum was classified as a subordinate species and was infrequently observed.

Nomenclature

 * quadridens. Formica quadridens Fabricius, 1793: 362 (w.) FRENCH GUIANA. [Junior primary homonym of Formica quadridens De Geer, 1773: 609 (now in Cephalotes).] Junior synonym and hence first available replacement name: Ectatomma brunnea Smith, F. 1858b: 103; designated by Bolton, 1995b: 187. Mann, 1916: 405 (m.); Santschi, 1921g: 83 (q.); Wheeler, G.C. & Wheeler, J. 1952a: 131 (l.). Combination in Ectatomma: Mayr, 1862: 732. Senior synonym of brunnea: Roger, 1860: 307.
 *  brunneum. Ectatomma brunnea Smith, F. 1858b: 103 (w.q.) BRAZIL. Junior synonym of quadridens: Roger, 1860: 307, and hence first available replacement name for Formica quadridens Fabricius, 1793: 362. [Junior primary homonym of Formica quadridens De Geer, 1773: 609 (now in Cephalotes).]; designated by Bolton, 1995b: 186.

Ectatomma brunnea

Syntype worker in. “Santarem” (Brazil). The syntype queen can not be positively identified. In there is another worker and another queen, also from the type-locality of Santarem, but the worker has passed through the Farren White collection.