Abstract
Major workers of O. longinoda mark their territories with persistent phermones that are distinguishable to the ants at the colony level. Workers detecting the deposits of an alien colony respond with increased amounts of aversive and aggressive behavior, and they later recruit nest-mates to the area at a higher rate. Colonies entering a field impregnated with their own scent also gain an initial advantage in warfare with other colonies. The pheromones are located at least in part in drops of rectal sac fluid deposited by workers over the territorial surface.