Glandular sources of alarm pheromones in the ant Formica rufibarbis (Hymenoptera Formicidae)

The alarm behaviour of the ant Formica rufibarbis was investigated by laboratory bioassays in which different exocrine glandular secretions were tested. This was done in order to identify glandular sources of the alarm pheromones involved. Experiments revealed that poison and mandibular glands play an important role in this context. Thus, F. rufibarbis seems to adopt a multisource alarm communication system, in which secretions from more than one glandular system are employed. However, a multicomponent alarm system, in which alarm communication is regulated by more than one substance (each with a different volatility), can not be excluded. Results are discussed also in the light of the important role this species plays in host-parasite relationships with other ants.