2,3-dimethyl-5-(2-methylpropyl)pyrazin, a trail pheromone component of Eutetramorium mocquerysi Emery (1899) (Hymenoptera : Formicidae)

The ant Eutetramorium mocquerysi (Myrmicinae) is endemic to the island of M adagascar. During foraging and nest emigration the ants lay recruitment tra ils with secretions from the poison gland. We identified three pyrazine com pounds in the poison gland secretion: 2,3-dimethyl-5-(2-methylpropyl)pyrazi ne 1, 2,3-dimethyl-5-(3-methylbutyl)pyrazine 3, 2,3-dimethyl-5-(2-methylbut yl)pyrazine 4. Only the first component elicited trail-following behavior i n the ants. We were unable to investigate whether the other pyrazine compon ents have a synergistic function.