ANTS (HYMENOPTERA: FORMICIDAE) OF THE DRY TORTUGAS, THE OUTERMOST FLORIDA KEYS

Abstract

We examined the distribution of ants on the Dry Tortugas, the outermost of the Florida Keys. These small islands are important nesting grounds for sea turtles and sea birds. We sampled ants on the five vegetated islands: Garden Key, Loggerhead Key, Bush Key, Long Key, and East Key. We found 17 ant species, seven of which had not been recorded from the Dry Tortugas. Paratrechina longicornis was common on four of five islands. Otherwise, the five islands had strikingly different ant faunas. On Garden Key, Solenopsis geminata was dominant, and Pheidole megacephala was absent. On Loggerhead Key and Bush Key, Ph. megacephala was dominant, and S. geminata was absent. On Long Key, vegetated primarily with mangrove, the most common ant was the arboreal Pseudomyrmex elongatus. On sparsely-vegetated East Key, all ants were uncommon. Twenty ant species are now known from the Dry Tortugas: eight New World and 12 Old World species. Only Solenopsis globularia is an undisputed Florida native. Florida specimens previously identified as C. tortuganus are actually Camponotus zonatus; true C. tortuganus are Bahamian. The two dominant ant species, Ph. megacephala and S. geminata, may pose a threat to native fauna, including sea turtle and sea bird nestlings.