Alarm pheromones in the genus Manica derived from the mandibular gland

The alarm pheromones present in the mandibular glands of Manica mutica and M. bradleyi are dominated by a novel C₁₀ ketone, 4,6-dimethyl-4-octene-3-one (manicone). Two other new insect pheromones, 4-methyl-3-hexanone and 3-decanone, are also present. In addition, two characteristic myrmicine alarm pheromones, 3-octanone and 4-methyl-3-heptanone, have been identified as mandibular gland constituents. While manicone functions as a powerful releaser of alarm behaviour for Manica workers a much weaker response was obtained to the other identified 3-alkanones. The significance of the occurrence of 3-ketones in members of the genus Manica and species in other genera of the Myrmicinae is analysed in terms of the accepted phylogeny of this subfamily.