EN
Dealate gynes of Formica pratensis Retz., after their nuptial flight, were observed heading for colonies of their potential temporary host species in a jsand dune habitat în southern Finland. Two F. pratensis gynes, one within a nest area of Formica cinerea Mayr, and one close to a nest of Formica lusatica Seifert, were noticed walking with a F. cinerea and F. lusatica worker respectively in their mandibles. So far such peculiar behaviour preceding dependent colony founding has only been known in gynes of the subgenus Chthonolasius Ruzs., obligate temporary social parasites. Observations were carried on in June 2006.