LAUSR

Significance Moths have served as historical models for animal communication studies. As their sex pheromone system is expected to be fine-tuned and under stabilizing selection, understanding its evolution has attracted interest for a long time. In the species Spodoptera littoralis and S. litura, the major component of the sex pheromone is an unusual compound, lacking in other species of the same genus. Building on the recent identification of a receptor narrowly tuned to this compound in S. littoralis, we investigated its evolution in the genus Spodoptera. We found that gene duplication followed by mutations that modified the binding pocket of the receptor led to the emergence of a new pheromone system in the common ancestor of S. littoralis and S. litura.