The Pheromone Landscape of Apis mellifera: Caste-Determined Chemical Signals and Their Influence on Social Dynamics

Abstract

A honeybee (Apis mellifera) colony is a superorganism of complex social dynamics. Within the colony, communication between individuals and castes is crucial for maintaining homeostasis. Such complex interactions are possible thanks to semiochemicals called pheromones. The spectrum of pheromonal communication in bee colonies is wide and differs between castes, especially the queen and the workers. Gland morphology and compounds of secretions result in alterations in both physiological and behavioral responses to certain pheromones in castes. The queen’s glands produce pheromones that maintain her reign and induce division of labor among workers. Workers’ pheromones are adapted to multiple tasks performed by this caste within the colony. This review outlines a neurophysiological pathway in the perception pheromone molecule, with a specific description of the individual anatomical structures essential for the path, such as the morphology of antennae, sensilla, antennal lobes and mushroom bodies. Later on, the study provides insight into specific aspects of the differences between the two castes (queen and workers) in terms of complex pheromonal communication in the hive, by describing the pheromones present in it (QMP, tergal gland pheromone, Dufour gland pheromone, Nasonov pheromone, sting alarm pheromone and tarsal gland pheromone).