Azteca aurita group

Based on [[Media:Longino J 2007.pdf|Longino, J.T. 2007. A taxonomic review of the genus Azteca in Costa Rica and a global revision of the aurita group. Zootaxa. 1491:1-63. PDF]] and [[Media:Guerreo et al 2010.pdf|Guerrero, R. J., J. H. C. Delabie & A. Dejean. 2010. Taxonomic contribution to the aurita group of the ant genus Azteca (Formicidae: Dolichoderinae). Journal of Hymenoptera Research. 19(1):51-65. PDF]]

Species

 * Azteca aurita
 * Azteca diabolica
 * Azteca lallemandi
 * Azteca lanuginosa
 * Azteca laurae
 * Azteca linamariae
 * Azteca nanogyna
 * Azteca pilosula
 * Azteca schimperi
 * Azteca snellingi

Diagnosis
Longino (2007) - Queen and worker: Palpal formula 4,3; middle and hind tibia lacking apical spur; anteromedial border of clypeus strongly convex and extending well beyond anterolateral clypeal lobes, HLB/HLA > 1.04. Queen: general body size small, similar in size to major workers; integument extremely smooth and shining, glass-like, with appressed pubescence extremely dilute; pilosity, when present, a stubble of short, stiff, fully erect setae; petiole bluntly subpyramidal to bilobed, never flat and scale-like.

Worker: Head always cordate, with variable tendency for posterolateral portions of occipital border to be drawn out into angular projections; scape, tibiae, lateral and posterior margins of head, and mesosomal dorsum devoid of setae; mandibles either of two forms, both unique to the species group: (1) dorsal surface strongly flattened, densely and finely striate, mat, or (2) dorsal surface convex and shiny, masticatory margin strongly sinuous, with large, projecting apical tooth; petiole as in queen.

Guerreo et al. (2010) - Longino (2007) proposed four features that distinguish the species in the aurita group from other species of ants of the genus Azteca (see introductory section), but one of those, the proportion HLB/HLA > 1.04, is not a consistent and stable feature within some of the females studied here (e.g., A. linamariae paratype). This trait, therefore, should not continue to be used as diagnostic tool for the aurita group while all the other traits are strongly consistent: the palpal formula is 4,3; the middle and hind tibia lack an apical spur; the anteromedial border of the clypeus is strongly convex and extends well beyond the anterolateral clypeal lobes. These traits can, however, still be of great taxonomic value for separating the aurita group from other groups of species in the genus Azteca.

Biology
Longino (2007) - Members of the A. aurita species group are widespread but rare. They construct carton nests on the branches of trees, nests which are always bare of epiphytes (they do not form ant gardens).

The diminutive and highly derived queens of the group suggest a social parasitism syndrome (Forel 1928, Hölldobler and Wilson 1990). Species in the A. aurita group have queens that are about the same size as workers, and the gaster is very small in proportion to the rest of the body. This contrasts with more typical Azteca species, which have queens much larger than workers and with large gasters, presumably full of resources for founding new colonies on their own. It is difficult to imagine the small aurita-group queens doing so, and a more likely scenario is for aurita-group queens to insinuate themselves into established colonies of other species, killing the host queen and having the host workers rear the parasites’ offspring. It is not even clear how they function once established; aurita-group colonies are enormous, and it seems paradoxical that such small queens could generate sufficient eggs to populate them. The morphology of Azteca nanogyna carries this paradox to an extreme, and a possibility in this case is that A. nanogyna is a workerless social parasite.