Ability of Resident Ants to Destruct Small Colonies ofSolenopsis invicta(Hymenoptera: Formicidae)

Abstract

The ant Solenopsis invicta Buren has spread across the United States and is reported to have significantly reduced the diversity of the native ants. Much of this spread is occurring on land that has been repeatedly disturbed by continually changing land use practices. S. invicta seems to outcompete and eliminate other resident ant species. However, this inference may not be true because several resident native ant species are known to persist in S. invicta-infested areas. Thus, in this study, we analyze the aggressive interaction between selected resident ants and S. invicta by evaluating whether some of these ants are capable of attacking small worker-defended S. invicta colonies or are instead attacked by the S. invicta colonies. Our results suggest that the native ant species Monomorium minimum (Buckley), Pheidole dentata Mayr, and Solenopsis molesta (Say) and exotic tramp ants Tetramorium bicarinatum (Nylander) and Monomorium pharonis (L.) do interact with the S. invicta and will attack and eliminate worker-defended S. invicta colonies of varying sizes ranging from 30 to 480 workers. M. minimum, P. dentata, S. molesta, T. bicarinatum, and M. pharonis also were observed to prey upon S. invicta brood once most of the defending workers were eliminated. The native species Forelius sp. was not observed to invade the S. invicta colonies; instead, it prevented S. invicta workers from leaving their nest to forage, which may have contributed to the decline of S. invicta colonies of up to 60 workers over time.