Arboreal Ant Community Patterns in Brazilian Cocoa Farms

Abstract

The distribution of arboreal-foraging ants on cocoa trees was investigated at the Centre for Cocoa Research in Bahia, Brazil. The interactions between ant species were quantified using data on the presence or absence of ant species on 1100 cocoa trees. The distribution of ants was also mapped in four 30 x 40 m plots of cocoa, and the species richness and biomass of ants was assessed by chemical knockdowns from within the territories of five of the dominant ant species. Ninety-one species of ant were encountered, of which seven reached dominant status. A quantitative evaluation of the number of positive and negative associations between each ant species confirmed the status of most of these dominants and also indicated that a further 10 species may have sub-dominant status. The dominants were distributed in a mosaic-like fashion and, except in an old, non-pesticide-treated cocoa plot, gaps in the mosaic were few. Some of the dominant ants influenced the number of associated ant species, the length of those ant species with which they were able to co-exist, and also the species composition of ants within their territory