Separating effects of species identity and species richness on predation, pathogen dissemination and resistance to invasive species in tropical ant communities

Ants are abundant in natural and managed tropical ecosystems and can have an impacton herbivorous arthropods, as well as plant pathogens. Although it has been shown f orplants that the diversity of communities can result in improved ecosystem functioning,it remains uncertain how the species richness of ants affects multiple ecosystemservices and disservices.2 In the present study, we used experimentally enhanced natural gradients in ant speciesrichness on 100 cacao trees in a plantation aiming to analyze the effect of ant speciesidentity and species richness on predation pressure and the incidence of cacao podborer (CPB), as well as the spread of black pod disease (BPD).3 Ant species richness did not signicantly improve predation of experimentally exposedinsects, and was not associated with a reduction in the incidence of CPB. However,the incidence of BPD was higher in ant species rich trees, presumably because moreant species were pathogen vectors. The identity of the dominant ant species affectedthe incidence of CPB and BPD, as well as predation pressure.4 Although both ant species richness and identity affected ecosystem services anddisservices delivered by the ant community, the results of the present study suggestthat the identity of dominant ants is the main driver for ecosystem services in thesesystems.