Rank orders and division of labour among unrelated cofounding ant queens.

Young, unrelated queens may cooperate in colony founding (pleometrosis) in many species of ants. Whereas the founding queens of many 'advanced' species rely completely on body reserves in order to rear their first young, queens of the ponerine Pachycondyla 'inversa' forage for food. In founding associations, only one queen specializes in this risky task. Here we show that the division of labour is strongly affected by aggressive interactions between cofounding queens: the dominant remains in the nest and guards the brood, whereas the subordinate is forced to leave and forage. The frequency of queen antagonism increased with the duration since food was last added to the foraging arena. Egg-laying rates did not differ significantly between nest-mate queens, but dominant queens destroyed and ate some of the eggs laid by subordinates.

Chemical profiles, division of labor and social status in Pachycondyla queens (Hymenoptera: formicidae).

Queens of the neotropical ponerine ant Pachycondyla cf. 'inversa' may co-operate during colony founding. One of several co-founding queens specializes in foraging, whereas the others remain in the nest and guard the brood. Division of labor is achieved by aggressive interactions, which result in the formation of dominance hierarchies. Gas chromatography and mass spectrometry of cuticular hydrocarbons obtained from live queens by SPME revealed consistent differences between the patterns of cuticular hydrocarbons of queens with high versus low rank: only high-ranking queens showed considerable amounts of cuticular pentadecane (n-C15) and heptadecene (n-C17:1). These two substances presumably originate from the queens' Dufour glands.