The characterization of emerging tramp ant communities (Hymenoptera: Formicidae) in residential neighborhoods of southern Puerto Rico.
This study characterizes the composition of an emerging tramp ant community in a tropical urban biome. Ant community dynamics were examined for one year in urban housing developments of different ages (one, four, and eight years since construction) in Santa Isabel, Puerto Rico. Each development represented a different period of recovery after a major environmental disturbance (initial clearing of the land). Although all three sites were located contiguously in what had previously been a single agricultural field, the species richness, relative ant abundance, frequency, and species evenness were found to be different for each development. For example, in the one-year-old site, a total of 58,000 ants were collected representing 14 different species. Two species, (Solenopsis invicta and Brachymyrmex sp. 1) accounted for >75 percent of all ants collected. In the four-year-old site, 99,000 ants were collected representing 20 species. Yet, the community was dominated by three tramp species (Solenopsis invicta, Pheidole fallax, and Monomorium destructor). Twenty-one species were identified in the eight-year-old site (88,000 ants), but four major pest species (Solenopsis invicta, Paratrechina longicornis, Pheidole fallax, and Pheidole moerens) represented >75 percent of the ants collected. Interestingly, the ant communities found within each of the developments consisted of old world, new world, and native species. These species would never co-exist under natural conditions. This study is the first to characterize the "melting pot" of non-native ant species as part of the emerging urban pest ant complex that has recently arisen in tropical urban habitats around the globe.