The route of Formica polyctena Forst. as a factor promoting emancipation of Formica fusca L. slaves from colonies of Polyergus rufescens (Latr.) (Hymenoptera: Formicidae)

Formica fusca L. slaves from colonies of Polyergus rufescens (Latr.) tend to establish small homospecific satellite nests close to a main nest. P. rufescens maintains the integrity of a mixed colony by means of peculiar integration raids (Czechowski 2005). The present paper describes the history of a group of such satellite nests, temporarily separated from the main nest by a foraging route of Formica polyctena Forst. impassable to P. rufescens. The ex-slaves had managed to adopt F. fusca gynes and raised some homospecific worker pupae before the F. polyctena route disappeared and P. rufescens started to raid their nests. During the raids, the mutual attitude of the slave-makers and the ex-slaves quickly evolved from hostility to friendly relations.