Intracolony chemical communication in social insects

Abstract

Chemical messengers are the primary mode of intracolony communication in the majority of social insect species. Chemically transmitted information plays a major role in nestmate recognition and kin recognition. Physical and behavioral castes often differ in chemical signature, and queen effects can be significant regulators of behavior and reproduction. Chemical messengers themselves differ in molecular structure, and the effects on behavior and other variables can differ as a consequence of not only molecular structure of the chemical messenger itself but also of its temporal expression, quantity, chemical blends with other compounds, and effects of the environment. The most studied, and probably the most widespread, intracolony chemical messengers are cuticular hydrocarbons (CHCs). CHCs are diverse and have been well studied in social insects with regard to both chemical structure and their role as pheromones. CHCs and other chemical messengers can be distributed among colony members via physical contact, grooming, trophallaxis, and contact with the nesting substrate. Widespread intracolony distribution of chemical messengers gives each colony a specific odor whereby colony members are integrated into the social life of the colony and non-members of the colony are excluded. Colony odor can vary as a function of genetic diversity within the colony, and the odor of a colony can change as a function of colony age and environmental effects. Chemical messengers can disseminate information on the presence of reproductives and fertility of the queen(s) and workers, and queen pheromone can play a significant role in suppressing reproduction by other colony members. New analytical tools and new avenues of investigation can continue to expand knowledge of how individual insects function as members of a society and how the society functions as a collective.