Cooperation, Conflict, and the Evolution of Queen Pheromones

Abstract

While chemical communication regulates individual behavior in a wide variety of species, these communication systems are most elaborated in insect societies. In these complex systems, pheromones produced by the reproductive individuals (queens) are critical in establishing and maintaining dominant reproductive status over hundreds to thousands of workers. The proximate and ultimate mechanisms by which these intricate pheromone communication systems evolved are largely unknown, though there has been much debate over whether queen pheromones function as a control mechanism or as an honest signal facilitating cooperation. Here, we summarize results from recent studies in honey bees, bumble bees, wasps, ants and termites. We further discuss evolutionary mechanisms by which queen pheromone communication systems may have evolved. Overall, these studies suggest that queen-worker pheromone communication is a multi-component, labile dialog between the castes, rather than a simple, fixed signal-response system. We also discuss future approaches that can shed light on the proximate and ultimate mechanisms that underlie these complex systems by focusing on the development of increasingly sophisticated genomic tools and their potential applications to examine the molecular mechanisms that regulate pheromone production and perception.

The influence of slavemaking lifestyle, caste and sex on chemical profiles in Temnothorax ants: insights into the evolution of cuticular hydrocarbons

“…Specific compounds that are characteristic for queens (queen pheromones) have been identified in various species [54,77,78]. However, our study is one of a few that revealed systematic chemical differences between castes across multiple species.…”

Comparative analysis of fertility signals and sex-specific cuticular chemical profiles of Odontomachus trap-jaw ants

“…4, Table 2; Smith et al, 2014). Many studies of social insect fertility signals have noted potential homologies with the contact sex pheromones of females of solitary insect species Kocher and Grozinger, 2011;Van Oystaeyen et al, 2014;Oi et al, 2015). Indeed, sex-based differences in the cuticular chemical profiles of males and females are the basis for short-range mate recognition for many solitary insects (Tregenza and Wedell, 1997;Ferveur and Cobb, 2010;Ginzel, 2010).…”

“…Sexually dimorphic cuticular chemical profiles are thought to be the ancestral condition from which eusocial queen signals evolved, because of their widespread use as sex-specific mate recognition signals in solitary insects, including solitary and primitively eusocial Hymenoptera (Paulmier et al, 1999;Ayasse et al, 2001;Liebig et al, 2009;Kocher and Grozinger, 2011;Van Oystaeyen et al, 2014;Oi et al, 2015). Further investigation of the hydrocarbon patterns of males relative to those of female castes may prove essential in understanding the evolution of chemical signaling in social insects.…”

In-Hive Miticides and their Effect on Queen Supersedure and Colony Growth in the Honey Bee (Apis mellifera)

“…Nonetheless, because queen supersedure has become increasingly problematic in commercial beekeeping operations [36][37][38], it remains a high priority to identify the causes of premature supersedure. Previous studies have reported differences in the chemical composition of the queen mandibular gland [52,[55][56][57][58] and the Dufour's gland [59] based on the queen's reproductive state and insemination quantity, therefore it would be very telling if there were significant differences in queen pheromones between queens raised in miticide-free versus miticideladen beeswax cups, and if so, to what degree workers inside the colony perceive these differences.…”