• An odorant receptor SfruOR37 in Spodoptera frugiperda robustly responds to linalyl acetate. • Several non-conserved residues in SfruOR37 mediated the binding affinity to linalyl acetate. • Linalyl acetate trigger robust EAG responses and a clear repellent effect on adult S . frugiperda . Insects depend on sophisticated olfactory systems for essential behaviors, with odorant receptors (ORs) lying at the core of odor detection. Spodoptera frugiperda is a major global agricultural pest, but the response profiles of its ORs remain largely unresolved. Here we focused on the functional characterization of SfruOR37 in S . frugiperda , an ortholog of Helicoverpa armigera HarmOR50 – which responds to (±)-camphor, an important plant volatile. Tissue expression analysis showed that SfruOR37 is specific expressed in the antennae of both sexes. Using Xenopus laevis oocytes, we functionally screened candidate ligands and identified linalyl acetate as the most potent activator of SfruOR37. To elucidate the binding mechanism between this receptor and its ligand, we performed molecular docking and dynamics simulations, which highlighted several non-conserved residues (notably S151, Y155, and Y325) likely shaping the SfruOR37 binding pocket and mediating the binding affinity to linalyl acetate. Electroantennogram (EAG) recordings demonstrated that linalyl acetate effectively elicits significant electrophysiological responses in adult antennae. In behavioral assays, linalyl acetate elicited a pronounced repellent effect on adult S . frugiperda . Together, our results illuminate how conserved ORs can diverge functionally within Lepidoptera and how such divergence contributes to ecologically relevant olfactory coding. Finally, by establishing linalyl acetate as a behaviorally active repellent for S . frugiperda , this study provides a theoretical basis for developing odorant-based, eco-friendly pest control strategies.
Wang et al. (2026) studied this question.