Identification of oviposition attractants for Peridroma saucia based on characterization of the female antennal‐predominant odorant‐binding protein PsauOBP6

BACKGROUND: The variegated cutworm Peridroma saucia has recently emerged as a polyphagous pest causing substantial crop damage in the Huang-Huai River Basin in China. Oviposition attractants are promising tools for developing behavior-based pest management strategies. Functional characterization of female antennal-predominant odorant-binding proteins (OBPs) provides an effective approach for identifying oviposition attractants for P. saucia. RESULTS: Transcriptome analysis combined with reverse-transcription PCR and quantitative real-time PCR identified an odorant-binding protein, PsauOBP6, which was predominantly expressed in the antennae of female P. saucia. Binding free energy calculations and fluorescence binding assays revealed that PsauOBP6 exhibited a high affinity for eight host plant-derived odorants. Subsequent Y-tube olfactometer assays demonstrated that three of these compounds, linalool, farnesol and (Z)-3-hexenyl butyrate, significantly attracted female P. saucia. In cage oviposition assays, tobacco plants treated with each compound (optimal dose: 2 mg per plant) received significantly more eggs than the untreated controls. Finally, molecular docking confirmed that His110 and Phe122 are key amino acid residues that mediate the binding of PsauOBP6 to linalool, farnesol and (Z)-3-hexenyl butyrate. CONCLUSION: The plant volatiles linalool, farnesol and (Z)-3-hexenyl butyrate, which exhibit a strong binding affinity for PsauOBP6, significantly attract female P. saucia and stimulate oviposition. These findings provide a solid foundation for developing effective attractants that can be incorporated into sustainable integrated management strategies for P. saucia. © 2026 Society of Chemical Industry.