Advances in the Study of Olfaction in Eusocial Ants

SIMPLE SUMMARY: In contrast to solitary insects such as the fruit fly or mosquito, eusocial ants form colonial societies comprised of reproductives (female queens and short-lived males) and thousands of sterile female offspring known as workers. Social behaviors such as nursing the queen’s offspring, foraging for food, and nest defense emerge from the collective behavior of the workers. Importantly, these behaviors critically depend on the exchange of information through the detection of chemical cues in the environment. While research efforts have historically aimed to understand the chemical ecology of these social insects, advances in the application of molecular technology over the past decade have facilitated novel studies that bridge the gap between social behaviors and olfaction. Here, we review major advances in the study of molecular olfaction in eusocial ants and highlight potential avenues for future research. ABSTRACT: Over the past decade, spurred in part by the sequencing of the first ant genomes, there have been major advances in the field of olfactory myrmecology. With the discovery of a significant expansion of the odorant receptor gene family, considerable efforts have been directed toward understanding the olfactory basis of complex social behaviors in ant colonies. Here, we review recent pivotal studies that have begun to reveal insights into the development of the olfactory system as well as how olfactory stimuli are peripherally and centrally encoded. Despite significant biological and technical impediments, substantial progress has been achieved in the application of gene editing and other molecular techniques that notably distinguish the complex olfactory system of ants from other well-studied insect model systems, such as the fruit fly. In doing so, we hope to draw attention not only to these studies but also to critical knowledge gaps that will serve as a compass for future research endeavors.