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Species: Azteca instabilis   (Smith, 1862) 

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Taxonomic History (provided by Barry Bolton, 2023)

Tapinoma instabilis Smith, 1862b PDF: 31 (w.) PANAMA. Neotropic. Primary type information: Primary type material: 6 syntype workers. Primary type locality: Panama: (no further data) (R.W. Stretch). Primary type depository: BMNH. Type notes: Shattuck, 1994 PDF: 19, cites holotype + paratypes, but F. Smith never designated holotypes. AntCat AntWiki HOL

Taxonomic history

Combination in Liometopum: Mayr, 1878 PDF: 870.
Combination in Azteca: Emery, 1893l: 135.
// Distribution


  Geographic regions (According to curated Geolocale/Taxon lists):
    Americas: Belize, Brazil, Colombia, Costa Rica, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Peru, Suriname
  Biogeographic regions (According to curated Bioregion/Taxon lists):

Distribution Notes:

Kempf (1972) lists A. instabilis from scattered localities in Brazil, the Guianas, Peru, Colombia, Panama, Costa Rica, Honduras, Guatemala, Belize, and Mexico. I have examined material from Mexico, Honduras, Nicaragua, Costa Rica, Panama, and Bolivia.


Natural History:

Azteca instabilis is the largest species in the genus. It occurs in wet to dry forest habitats, usually below 500m elevation.

Azteca instabilis makes its nest in the hollow trunks of trees which have a large crevice or fissure at the base. When I encounter them, workers are issuing from the fissure in large numbers, usually ascending the tree and often blanketing the surrounding forest floor. In one case I was able to peer up into such a fissure, and I observed a very large carton nest filling the trunk cavity. Colonies can be long-lived. During extended field work at Sirena in Corcovado National Park, I frequently passed a large tree with a very active A. instabilis colony in the trunk, with workers flowing in and out of a large fissure at the base. I returned to the site 16 years later to find the same fissure with A. instabilis workers still active.

When examining Azteca queens in museum collections, A. instabilis is usually the most abundant species because the large queens frequently come to lights at night. This is in sharp contrast to most other Azteca, whose alate queens are usually encountered as diurnal strays, occasional specimens in Malaise traps, or parts of nest collections. This correlates with the fact that A. instabilis queen ocelli are absolutely and relatively far larger than ocelli on any other Azteca queen I have examined. The enlarged ocelli are not the result of an allometric relationship with head size, since A. sericea and A. sericeasur, with queens nearly as large, have tiny ocelli typical of smaller queens. Ocelli concentrate light and detect light of low intensity (Chapman 1982), suggesting a functional relationship between large ocelli and nocturnal habits.

Workers frequently forage on the surface, both day and night. They visit extrafloral nectaries, and may tend coccoid Hemiptera under small carton shelters.

Literature Cited

Taxonomic Treatment (provided by Plazi)

Scientific Name Status Publication Pages ModsID GoogleMaps
Azteca   Longino, J. T., 2007, A taxonomic review of the genus Azteca (Hymenoptera: Formicidae) in Costa Rica and a global revision of the aurita group., Zootaxa 1491, pp. 1-63: 8-10, (download) 8-10 21311
Azteca instabilis   Forel, A., 1899, Biologia Centrali-Americana; or, contributions to the knowledge of the fauna and flora of Mexico and Central America. Insecta. Hymenoptera. 3 (Formicidae)., London: Unknown Publisher: 107, (download) 107 8170
Azteca instabilis   Longino, J. T., 2007, A taxonomic review of the genus Azteca (Hymenoptera: Formicidae) in Costa Rica and a global revision of the aurita group., Zootaxa 1491, pp. 1-63: 35-37, (download) 35-37 21311 GoogleMaps

Specimen Habitat Summary

Found most commonly in these habitats: 22 times found in montane wet forest, 11 times found in rainforest, 3 times found in lowland rainforest, 4 times found in rainforest edge, 5 times found in CCL 700m., 2 times found in wet forest, 3 times found in dry forest, 1 times found in GLASNOST plot, STR 3km, La Selva, 2 times found in tropical wet forest, 1 times found in montane rainforest edge, ...

Found most commonly in these microhabitats: 6 times Sobre Vegetacion, 7 times at light, 3 times on low vegetation, 1 times Witheringia asterotricha stems, 2 times nest in live tree trunk, 4 times mercury vapor lamp, 1 times on tree trunk, 2 times at lights, 2 times arbol caido, 2 times on vegetation, 1 times nocturnal foragers, ...

Collected most commonly using these methods: 14 times Malaise, 13 times search, 12 times blacklight, 12 times fogging, 2 times light trap, 6 times Sweeping, 1 times direct collection, 1 times light, 1 times Malaise trap, 1 times mercury vapor light, 1 times miniWinkler, ...

Elevations: collected from 5 - 1290 meters, 247 meters average

Collect Date Range: collected between 1979-12-30 00:00:00.0 and 2016-05-31 00:00:00.0

Type specimens: syntype of Azteca instabilis: casent0903009; syntype of Azteca instabilis major: casent0909639, casent0909640; syntype of Azteca instabilis major: casent0903010

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