The Evolution of Personally Disadvantageous Punishment among Cofoundresses of the Ant Acromyrmex Versicolor

Cofoundresses of the desert fungus garden ant Acromyrmex versicolor exhibit a forager specialist who subsumes all foraging risk prior to first worker eclosion (Rissing et al. 1989). In an experiment designed to mimic a "cheater" who refuses foraging assignment when her lot, cofoundresses delayed/failed to replace their forager, often leading to demise of their garden (Rissing et al. 1996). The cheater on task assignment is harmed, but so too is the punisher, as all will die without a healthy garden. In this paper we study through simulation the cofoundress interaction with haploid, asexual genotypes which either replace a cheater or not (punishment), under both foundress viscosity (likely for A. versicolor) and random assortment. We find replacement superior to punishment only when there is no foraging risk and cheating is not costly to group survival. Generally, punishment is evolutionarily superior, especially as forager risk increases, under both forms of dispersal.