DIVISION-OF-LABOR IN THE NEOTROPICAL ANT, PACHYCONDYLA-STIGMA (PONERINAE), WITH SPECIAL REFERENCE TO MUTUAL ANTENNAL RUBBING BETWEEN NESTMATES (HYMENOPTERA)

In the ponerine ant species Pachycondyla stigma the social organizatio n and reproductive activity is closely linked with the rate at which i ndividual colony members perform mutual antennal rubbings with nestmat es, During these encounters the ants rub their antennae over the openi ngs of a front-tibial gland of the encountered nestmates. The insemina ted queen engaged in such mutual rubbings at a much higher rate than n on-inseminated queens and workers. The reproductive dominance of the m ated queen was further enhanced by extremely aggressive behavior of wo rkers toward other egg-laying queens. Once the mated queen was removed from the colony, mutual antennal rubbings among virgin queens and agg ressive behavior increased. We hypothesize that the tibial glands in t he front-legs of queens produce either an inhibitory chemical signal, or more likely, the secretion signals the reproductive state to nestma tes who might respond by refraining from reproduction.