Exotic ant activity in Biscayne National

The Schaus swallowtail (Heraclides aristodemus ponceanus) is an endangered butterfly with critically low numbers. Exotic ants such as the red imported fire ant (Solenopsis invicta) and elongate twig ant (Pseudomyrmex gracilis) are potentially notorious agents in the decline of the Schaus’ swallowtail and other rare butterflies. Sites in Biscayne National Park have been cleared of invasive plants and replanted with hostplants (torchwood and wild lime) for the Schaus’ swallowtail; exotic ants may become abundant in the cleared sites. Ant surveys were conducted in the campgrounds, restored sites, and intact hardwood hammock to determine ant activity. Torchwood, wild lime, and non-hostplants in the hardwood hammock were surveyed from their base to canopy for ant activity. Red imported fire ants were not the dominant species in the cleared sites and notably absent in the hardwood hammock. Native ant species were abundant in trees; however, another exotic ant, Wasmannia auropunctata, was common in arboreal and terrestrial environments. Red imported fire ants are not a threat to caterpillars in hardwood hammocks eliminating the need to control them chemically. Future work should investigate caterpillar-ant interactions on torchwood and wild lime in the hardwood hammock.