Worker's age regulates the linear dominance hierarchy in the queenless ponerine ant, Pachycondyla sublaevis (Hymenoptera: Formicidae)

Abstract

Abstract. The Australian ant Pachycondyla sublaevis has small colonies (2-18 workers) and no morphologically distinct queens. Instead, it exhibits a well-defined dominance hierarchy in which only the top-ranked worker is inseminated and has a well-developed ovary with matured oocytes. The dominance order is related to the age of workers but not their body size. That is, the top rank is occupied by young workers in most colonies and newly eclosed callows always fill the position next to the top. It is suggested that the dominance hierarchy of this ant species has evolved as a consequence of intra-colonial competition for reproduction. The frequency of dominance displays was as low as 1·9 times or less per h in small colonies but increased exponentially up to 37 times per h in large colonies of more than 10 workers.