Ants (Hymenoptera: Formicidae) on non-native neotropical ant-acacias (Fabales: Fabaceae) in Florida

*[One of the best-known symbioses in the Neotropics is the association between ant-acacias & Pseudomyrmex ants that live in the acacia’s hollow thorns. We surveyed ants on 2 species of ant-acacia, Acacia cornigera (L.) & Acacia sphaerocephala Schlechtendal & Chamisso, growing outside their native range at 5 sites in Florida. We found 11 ant species: 5 native Florida ants [Brachymyrmex sp. nr. obscurior, Camponotus floridanus (Buckley), Pseudomyrmex cubaensis (Forel), Pseudomyrmex ejectus (Smith), & Pseudomyrmex elongatus (Mayr)], 2 Neotropical exotics [Camponotus sexguttatus (Fabr.) & Pseudomyrmex gracilis (Fabr.)], & 4 Old World exotics [Monomorium floricola (Jerdon), Paratrechina longicornis (Latreille), Pheidole megacephala (Fabr.), & Technomyrmex albipes (Smith)]. Only the 2 Neotropical exotics, Ps. gracilis & C. sexguttatus, inhabited thorns with holes that appeared to have been perforated by ants as entrances. For Ps. gracilis, & perhaps also for C. sexguttatus, their association with ant-acacias in Florida represents the reconstitution in an exotic locale of a facultative symbiosis evolved in the Neotropics.]