Social environmental factors influencing mutual recognition of inviduals in the ant Leptothorax Lichtensteini bondr. (Hymenoptera: Formicidae).

In the framework of a study of the mechanisms underlying mutual recognition phenomena between members of a Lepthothorax lichtensteini ant colony, we conducted two series of experiments, designed to investigate the effects of an experimental separation of individuals from their colony upon being reintroduced. Two parameters were examined: the length of the separation period and the social experience lived by these individuals during their separation. Workers living in groups of 5 individuals from the same colony or in an alien colony where they had been previously adopted were rejected by their own sisters when they were reintroduced into their colony, after a 70- and a 45-day period of separation respectively. We moreover investigated the effects on group cohesion of separating one colony into two halves, depending on whether of not the queen was present. After a 120-day separation, the 2 halves of a colony did not merge rapidly and without aggressivity, unless the single reproductive female was transferred from the one nest to the other every 15 days during the separation period. In the light of the results obtained, we conclude that: © 1989 Elsevier Science Publishers B.V. (Biomedical Division). All rights reserved.