Probable functions for a previously unrecognized pheromone in ants of the genus Myrmica

A previously unknown pheromone has been detected in workers of Myrmica rubra when an extract, usining a polar solvent, of the VIIth abdominal sternite was shown to attract ants over short distances and to act in synergy with the trail pheromone to enhance its effect. This new factor has now been shown to help the foraging workers to distinguish between recent and older trails and to confer on the trails a species-specific character (demonstrated for five species of Myrmica ) that the trail pheromone alone does not possess.