Ant Trail Pheromones

This chapter presents the chemistry and stereobiology of trail pheromones. It also discusses the source and specificity of ant trail pheromones by illustrating the example of dolichoderine ants, myrmicine ants, formicine ants, ecitonine ants, ponerine ants, and aneuretine ants. Social insects utilize an array of pheromones to maintain the high level of organization in their colonies. Many species of ants and termites that are essentially wingless lay terrestrial odor trails leading to food sources or nesting sites. In the termites, a gland on the ventral surface of the abdomen serves as the source of the trail pheromones, but in ants, pheromones can arise from a number of glandular sources—including the hind gut, rectal gland, poison gland, etc. The glandular origins are usually determined by laying artificial trails with extracts of the various glands in a solvent such as ether, hexane, or acetone. The pheromonal transmission of information in most insects is accepted to be through multicomponent pheromones consisting of several stimulus compounds. In many examples, the precise qualitative blend of the components gives the species specificity to the pheromonal signal.