Interference and Exploitation in a Guild of Woodland Ants

Abstract

This paper evaluates the effects of exploitation and interference on the foraging behavior of nine species of ants in a Maryland woodlot. These species overlapped substantially in both the size and type of prey taken. Three types of encounters occurred between species at baits: attacks, avoidance, and coexistence. Camponotus ferrugineus, Lasius alienus, Prenolepis imparis, and Formica subsericea fell into a dominant group, while the Myrmica spp. (M. punctiventris and M. emeryana), Aphaenogaster rudis, Tapinoma sessile, and Leptothorax curvispinosus were increasingly subordinate. Subordinate species significantly reduced feeding time when in the presence of other species. Exploitative abilities of the species were studied by observing ant activity at baits. Leptothorax curvispinosus, Aphaenogaster rudis, and the Myrmica spp. arrived first at a higher percentage of baits than did Camponotus ferrugineus, which was significantly slower at finding new food sources. An inverse correlation was found between exploitative and interference ability, which enabled the subordinate species to obtain resources. In most cases, the speed of bait location was no correlated with distance of the bait from the colony.