Exotic ants in urban environments of Santa Marta, Colombia

Abstract

The fauna of exotic ants was characterized, evaluating its incidence and variation in urban environments of the city of Santa Marta. As an approximation of the heterogeneity of the urban landscape, three types of environments were established: district parks, theme parks and natural areas, which exhibit main differences in tree and gray cover. In total, 16 sites distributed in the three environments were selected; each site was sampled four times considering the climatic seasons. Pitfall traps, mini-Winkler extractors, baits, and manual collection were the methods used to collect both native and exotic ants. The richness and abundance of exotic and native ant species between environments, microhabitats and climatic seasons were analyzed and compared. The distribution in Colombia was recorded, as well as information on its possible origin and native distribution for each of the exotic species recorded. Seven subfamilies, 42 genera, 88 species and nine morphospecies were collected. Of the 97 species collected just eight correspond to exotic species. Urban parks recorded the highest richness of exotic species on a spatial and temporal scale. The capture frequencies and range-abundance curves indicate that Pheidole indica is the predominant species in district parks, while Paratrechina longicornis and Trichomyrmex destructor are the most frequent in theme parks. Paratrechina longicornis, Monomorium pharaonis, and Tapinoma melanocephalum are widely distributed in Colombia, while P. indica, T. destructor, Tetramorium lanuginosum, T. simillimum, and Cardiocondyla emeryi have been recorded from few localities in the country. The spatial variation trend in this study indicates that there is a greater number of exotic ants in areas with less environmental heterogeneity, as is the case of district parks, as well as a lower proportion of these species in preserved natural areas.