Worldwide spread of Emery's sneaking ant, Cardiocondyla emeryi (Hymenoptera: Formicidae)
biogeography, Biological invasion, exotic species, Invasive species, island fauna
Cardiocondyla emeryi FOREL, 1881 has long been recognized as a cosmopolitan ant species, spread around the world by human commerce. To evaluate its worldwide distribution, I compiled published and unpublished C. emeryi specimen records from > 1000 sites. I documented the earliest known records for 109 geographic areas (countries, island groups, major islands, and US states), including several for which I found no previously published records: Antigua, Aruba, Barbuda, Bonaire, Comoro Islands, Congo (Republic), Curaçao, Dominica, Gambia, Honduras, Îles Éparses, Martinique, Montserrat, Nevis, St Lucia, St Martin, Trinidad, Turks & Caicos Islands, and Vanuatu. Originally from Africa, Cardiocondyla emeryi is now one of the most widespread ants in tropical and subtropical areas. Although C. emeryi is usually very inconspicuous, an exceptional aspect of its ecology is that it is one of the few ant species that actually appears to be more common in areas dominated by African big-headed ant, Pheidole megacephala (FABRICIUS, 1793). In areas where P. megacephala occurs at high density, few native invertebrates persist. Yet, at sites with high densities of P. megacephala on islands of the Pacific, Atlantic, and the West Indies, I usually also found C. emeryi. It may be that P. megacephala benefits C. emeryi indirectly, through elimination of competing ant species.