Azteca trigona

Azteca trigona

Some ants of the genus Zacryptocerus exhibit some kind of social parasitism where they follow pheromone trails of certain Azteca species, including Azteca trigona in order to find their food supply. This ant functions as an ‘information parasite’ (Adams 1990).

Azteca trigona ants are among a group of ants known for constructing carton nests. The production of large pendant carton nests by Azteca is a common phenomenon in moist to wet forests from Panama southward through tropical South America. Some of them are made by the A. aurita group, but the majority is made by the A. trigona group (Longino 2007). There are three ants of the genus Azteca exhibiting this same behaviour: Azteca aurita, Azteca chartifex and Azteca trigona. The A. aurita species group is widespread but rare. They construct carton nests on the branches of trees, nests which are always bare of epiphytes (Longino 2007).

The small and highly derived queens of the group makes one think of a social parasitism syndrome. Species in the A. aurita group have queens that are about the same size as workers. It’s highly improbable that this small queen will have sufficient resources to begin a colony on her own. The most likely scenario, then, is that the queens somehow penetrate already existing colonies of other species, kill the queen and have the workers of that same colony raise her offspring. Once the colony is established, it’s unclear how is grows, because they are massive in number and it’s unimaginable that such a small queen can generate enough eggs to populate them.

Azteca chartifex occurs in wet forest habitats. The same as A. aurita, these colonies occur in clusters of large, pendant carton nests. The carton has a dry paper-like texture. These nests, protected by the ants, are never penetrated by epiphytes or other plant roots. The nests are not necessarily encountered in very inconspicuous locations, as they can be found in very exposed and highly insolated environments. They can be found in greater abundance in seasonal moist to dry habitats (Longino 2007).

References:

Adams, E. S. (1990). Interaction between the ants Zacryptocerus maculatus and Azteca trigona: interspecific parasitization of information. Biotropica 22: 200-206.

Longino, J. (2007). A taxonomic review of the genus Azteca (Hymenoptera: Formicidae) in Costa Rica and a global revision of the aurita group. Zootaxa. 1491: 1-63.