Aggression and Gause's law in ants

ABSTRACT. Myrmica rubra societies were faced with intruders of the following species: M.rubra, M.sabuleti, Tetramorium caespitum, Lasius flavus and L.niger. The aggression of the resident workers was quantified by frequencies of mandible openings, seizings and gaster flexings. Intraspecific aggression was lower than interspecific, and it is suggested that this might be due to the polygynous behaviour of M.rubra. There was no simple relationship between the intensity of aggression and the taxonomic remoteness of the intruder species. Differences in the levels of the aggressive response need to be better understood by analysis of the eco-ethological interrelations of the species concerned.