Landscape genetics across the Andes mountains: Environmental variation drives genetic divergence in the leaf-cutting ant Atta cephalotes.

Distinguishing among the mechanisms underlying the spatial distribution of genetic variation resulting from the environmental or physical barriers from those arising due to simple geographic distance is challenging in complex landscapes. The Andean uplift represents one of the most heterogeneous habitats where multiple mechanisms may interact, confounding their relative roles. We explore this broad question in the leaf-cutting ant Atta cephalotes, a species that is distributed across the Andes mountains, using nuclear microsatellite markers and mtCOI gene sequences.

Yeasts associated with the worker caste of the leaf-cutting ant Atta cephalotes under experimental conditions in Colombia.

Yeasts isolated from the worker caste of the Colombian leaf-cutting ant, Atta cephalotes (Hymenoptera: Myrmicinae) were cultured and identified by molecular methods. Abundant, persistent, and omnipresent species were classified as "prevalent". Experimental data were compared with information gathered from published reports on the yeast species composition in other leaf-cutting ant species.

Immunity and survival response of Atta cephalotes (Hymenoptera: Myrmicinae) workers to Metarhizium anisopliae infection: Potential role of their associated microbiota.

Leaf-cutting ants of the genera Atta and Acromyrmex are at constant risk of epizootics due to their dense living conditions and frequent social interactions between genetically related individuals. To help mitigate the risk of epizootics, these ants display individual and collective immune responses, including associations with symbiotic bacteria that can enhance their resistance to pathogenic infections. For example, Acromyrmex spp.

Characterization of a New Set of Microsatellite Markers Suggests Polygyny and Polyandry in Atta cephalotes (Hymenoptera: Formicidae).

The leaf-cutting ant, Atta cephalotes L. (1758), is a major herbivore with great economic impact in the Neotropics. Because of its broad range and human-mediated dissemination, the ecology of this ant has received considerable attention; however, questions concerning its population genetics, dispersal, and social structure remain unexplored.