Molecular Mechanism of a Conserved Odorant Receptor in Detecting a Repellent Signal in the Rice Moth <i>Corcyra cephalonica</i>

The rice moth <i>Corcyra cephalonica</i>, a highly destructive pest found worldwide, with a wide-ranging diet and robust reproduction, severely damages various stored foods. A sensitive olfactory system is essential for insect behavioral perception, odorant receptors (ORs) play a crucial role in detecting volatile chemical cues in the living environment of insects. However, the reports on the identification and functional analyses of ORs in <i>C. cephalonica</i> are currently lacking. In this study, we identified CcepOR13, which clusters into the conserved lepidopteran OR42 ortholog family. TEVC recordings revealed its conserved function, and phenylacetaldehyde, 2-phenylethanol, cinnamaldehyde, and pentanal were identified as its main ligands. Behavioral experiments revealed that among these four ligands, <i>C. cephalonica</i> exhibited avoidance behavior only in response to 2-phenylethanol, and after dsRNA-CcepOR13 treatment, its electrophysiological and avoidance responses to 2-phenylethanol were significantly reduced. Our findings indicate that CcepOR13 is essential for 2-phenylethanol recognition by <i>C. cephalonica</i>, suggesting that the development of repellents for biological control is warranted.