Fine structure of the postpygidial gland in Aenictus army ants

Army ants of the genus Aenictus are characterized by the presence of a cons picuous postpygidial gland, which is the source of the trail pheromone. The paired gland at each side consists of a reservoir sac into which the secre tory cells open through their accompanying duct cells. The secretory cells are characterized by a well developed Golgi apparatus, numerous mitochondri a and strands of smooth endoplasmic reticulum. The reservoir opens near the abdomen tip, which facilitates deposition of the secretory products onto t he substrate. The large reservoir of the postpygidial gland may enable the incessant trail laying of at least one of the investigated species.