Raiding and foraging behavior of the blood-red ant, Formica sanguinea Latr. (Hymenoptera, Formicidae)

In this paper we report the results of a detailed study on the behavioral e cology of slave raiding and foraging activity in the European blood-red ant , Formica sanguinea Latr. The field study was conducted over art unbroken p eriod of 78 days, during which the activity of two dulotic colonies of this facultative slave-maker was observed for 10 h each day It was possible to observe 26 raids distributed over 23 days, among which 18 were followed by the sacking of nests belonging to the species F. cunicularia, F. fusca, and Lasius emarginatus, whereas 8 failed. Simple, continuous, and simultaneous raids occurred. We recorded the timing, frequency, distance, and direction of slave raids, including the number of participants and the type of booty . Particular attention was devoted to the scouting behavior and raiding org anization. Moreover, every day we observed foraging and predatory behavior, during which adult insects (mainly ants), seeds, and berries were retrieve d to the dulotic colonies. On the basis of our observations F. sanguinea se ems to be a very efficient slave-maker and predatory species of the Raptifo rmica subgenus. Moreover, its dulotic behavior may be regarded as a continu ation and an expansion of its foraging and predatory behavior, as predicted by Darwin's hypothesis for the origin and evolution of slavery in ants.