Aggression in wood ants (Formica polyctena Foerst., Hymenoptera,Formicidae)

The relationship between aggression and predation was surveyed in Red wood ants, in the field as well as under laboratory conditions. Aggression between wood ant nests is highest in early spring, and many wood ant wars break out then. The end of these wars coincides with a strong increase in prey density. Since the casualties are taken as food to the warring nests, a hypothesis is formulated that warfare between wood ant nests only occurs in periods when prey demand exceeds the supply. Protein-rich food in early spring is mainly for the benefit of the queens and the sexual larvae. Although the most obvious function of warfare is the defence of a foraging area, the main function may be the advancement of the mating flight dates of the queens in order to make the chance of propagating their genes greatest.