Distribution patterns of Paraguayan leaf‐cutting ants(AttaandAcromyrmex)(Formicidae: Attini)

Publisher Website
Google Scholar
Abstract
432 transects were run in 19 sites in Paraguay, encompassing 8 major habitat types, to examine the distribution patterns of the taxa of leaf‐cutting ants. Colonies of Acromyrmex were significantly correlated with decreasing habitat complexity, while colonies of Atta showed a similar, though non‐significant, trend. A mean of 3.04 species of leaf‐cutters was found per site, with a maximum of 7 species recorded. By comparing colony incidences of one genera with the other, intra‐generic competition is suggested. Discriminant analysis indicated that pasture species and colony densities were much more like those of cultivated land, and that disturbed habitats were much more variable in species composition and colony densities than undisturbed habitats. Canonical correlation analysis of standardized colony densities of 15 taxa of leaf‐cutters and 6 gross habitat variables permited the identification and quantification of their interrelations, and explained up to 73% of the variation in colony densities. A principal axis factor analysis corroborated these findings, and also gave estimates for the habitat niche breadths of the 15 taxa in terms of their unique variances.