Chemical and ethological studies of the trail pheromone of the ant Manica rubida (Hymenoptera: Formicidae)

ABSTRACT. The poison gland of Manica rubida contains nanogram quantities of four alkylpyrazines, methylpyrazine, 2,5-dimethylpyrazine, trimethylpyrazine and 3-ethyl-2,5-dimethylpyrazine, of which only the last induces pronounced trail-following behaviour. Myrmica rubra and M. rubida workers follow each other's trails equally well when allowance is made for the much greater size of M. rubida workers. The cross activity in trail-following between M. rubida, M. rubra and Tetramorium caespitum is understandable in terms of the amounts and proportions of the different pyrazines present in their glands and their responses to the synthetic substances and appropriate mixtures of them.