Abstract
Two types of I. purpureus v. viridiaeneus colony are described from an arid part of South Australia. Association with two plant species, predation on a termite, interactions with another ant species and rates of discovery of baits are recorded. In this locality I. purpureus v. viridiaeneus differed from I. purpureus sens. strict., of coastal, higher rainfall areas, in the dispersion of nests within the colony territory. The ecological significance of this is discussed.