Polymorphism and oligogyny in the ponerine antCentromyrmex bequaerti (Formicidae: Ponerinae)

Abstract

Centromyrmex bequaerti is a ponerine ant of the African equatorial forest which nests in the termitaries of diverse Termitinae and Macrotermitinae, occupying several chambers and galleries of the termitaries and preying on their guests. This species presents four traits convergent with termitolestic Myrmicinae: a parasitic nesting habit (but shelters directly in the cavities of the termitaries and not in the walls), blind workers, a strong dimorphism between the queens (20 mm in length) and the workers (from 5.75 to 12 mm total length) and polymorphism in the worker caste. We recorded two other traits considered as evolutionarily-derived: oligogyny, a kind of polygyny (the societies include up to 13 queens, but each queen lives in a separate cavity of the termitary) and large colon size. Behavioural observations show that there is a relationship between worker size and polyethism in this species. Although workers of all size classes participate in hunting, the media are more often engaged in this activity and the largest workers guard the nest entrance.