The Aversive Response of the Locust Locusta migratoria to 3-Octanone, an Odorant from Fungal Pathogens, Is Mediated by a Chemosensory Protein

(1) Locusts are important agricultural pests. Identifying harmful substances and avoiding them is for locusts’ survival; their abilities to do so remain be clarified. (2) We examined the electrophysiological (electroantennogram (EAG) single sensillum recording (SSR)) behavioral responses (preference behavior in a T-maze) of locusts 18 different compounds; (3) Of these compounds, 9 elicited strong EAG responses, 3 SSR neurons expressing locust odorant receptor (LmigOR3). The 11 chemicals that stronger or were selected evaluation locusts. Only 2-heptanone induced significant attraction at tested concentration. RNA interference (RNAi) LmigOR3 experiments revealed could detect 3-octanone. However, experiments, RNAi did not alter 2-heptanone-induced but increased by (4) Our results suggest broadly tuned expressed heterologous expression system exhibits narrow response spectrum, aversive 3-octanone, an from fungal pathogens, natural enemies, non-host plants, mediated LmigOR3. These findings enhance our understanding complex olfactory recognition mechanism insects.