Ectatomma tuberculatum

This ant can be a common and readily observable constituent of ant communities in favorable habitat, e.g., Brazilian cerrado.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Panama, Paraguay, Peru, Suriname, Trinidad and Tobago, Venezuela.

Biology
This ant is preyed on by the social parasite Ectatomma parasiticum.

Sanz-Veiga et al. (2017) -  was found to be the most common ant visitor to extrafloral nectaries of Tocoyena formosa plants occurring in a southeastern Brazilian cerrado study-site.

De Oliveira et al. (2015), studying ant occupancy of Cecropia trees in southwest Bahia, Brazil, found two colonies of  nesting in Cecropia pachystachya trees.

Longino (2003) - Wheeler (1986) observed a behavioral association between Crematogaster limata and the large ponerine ant Ectatomma tuberculatum on Barro Colorado Island in Panama. Ectatomma tuberculatum nests in the ground at the bases of trees. The nest entrance is surmounted by a 2-3cm wide thatch tube that extends about 15cm up the side of a tree trunk or smaller plant stem. Wheeler observed that polydomous C. limata nests were often located near the mouths of E. tuberculatum nests, and that C. limata carried out periodic “raids” into the these nests. The raids were abrupt and short-lived, with workers streaming into and out of a nest entrance for about an hour. Peak flux rates were about 170 workers entering and 170 workers exiting per 15 minute observation period. Wheeler writes “Encountering an E. tuberculatum, the smaller C. limata climbed up one of the larger ant's legs and onto its thorax and head. The E. tuberculatum worker stood still as the C. limata licked the dorsal surface, especially the head. E. tuberculatum did not react aggressively to the intruders. Occasionally, an E. tuberculatum worker opened her jaws as the C. limata licked the extended mouthparts. Then the C. limata worker climbed down and quickly left the nest.” Although Wheeler failed to observe the phenomenon during a brief visit to Finca La Pacifica in the dry forest habitat of northwestern Costa Rica, where she examined five E. tuberculatum nests, I suspect that the phenomenon occurs in Costa Rica. In the Atlantic lowlands I have seen several instances of large C. limata colonies with nests clustered in and around nest entrances of E. tuberculatum.

When alarmed, workers will feign death.

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.

Castes
Two size categories of queens were thought to exist in E. tuberculatum. The small queens were believed to be microgynes. Macrogynes were found to be approximately 20% larger in size and twice as heavy as microgynes (and up to three times heavier in terms of dry weight). Both types can be inseminated. They differ in the number of ovarioles per ovary (20 vs. 14)(Lachaud et al. 1999). Presently these small queens are classified as a parasitic ant species Ectatomma parasiticum.



Nomenclature

 *  tuberculatum. Formica tuberculata Olivier, 1792: 498 (w.q.) TRINIDAD. Smith, F. 1858b: 102 (m.); Wheeler, G.C. & Wheeler, J. 1952a: 129 (l.). Combination in Ectatomma: Smith, F. 1858b: 102. Senior synonym of tridentata: Smith, F. 1858b: 102; of ferrugineus: Emery, 1892b: 167; of irregularis, punctigerum: Weber, 1946a: 2; of acrista: Kempf, 1962b: 2.
 * tridentata. Formica tridentata Fabricius, 1804: 412 (w.) "America meridionali". Junior synonym of tuberculatum: Smith, F. 1858b: 102.
 * ferruginea. Ectatomma ferruginea Norton, 1868a: 61, pl. 2, fig. 4 (w.m.) MEXICO. Norton, 1868c: 5 (w.m., descriptions). Junior synonym of tuberculatum: Emery, 1892b: 167.
 * punctigerum. Ectatomma tuberculatum var. punctigerum Emery, 1890a: 56 (w.) VENEZUELA. Lever, 1930: 214 (q.). Junior synonym of tuberculatum: Weber, 1946a: 2.
 * acrista. Ectatomma tuberculatum subsp. acrista Forel, 1909a: 254 (w.q.) PARAGUAY. Junior synonym of tuberculatum: Weber, 1946a: 2. Revived from synonymy and raised to species: Brown, 1958g: 208. Junior synonym of tuberculatum: Kempf, 1962b: 2.
 * irregularis. Ectatomma tuberculatum var. irregularis Santschi, 1921g: 83 (w.) COLOMBIA. Junior synonym of tuberculatum: Weber, 1946a: 2.