Mating-Induced Upregulation of Ionotropic Receptor IR75q1 Mediates Oviposition Avoidance in Yellow Peach Moth

The yellow peach moth, Conogethes punctiferalis, is a devastating fruit-boring pest widely distributed across Asia. In recent years, it has caused increasingly severe damage to crops such as summer corn. Here, we investigated the role of the ionotropic receptor CpunIR75q1 in oviposition regulation. Antennal transcriptomic analysis identified 27 candidate CpunIRs, including an expanded IR75 subfamily. qPCR analysis revealed that CpunIR75q1 exhibited female-biased expression and was specifically upregulated in mated females. In two-electrode voltage clamp recordings, the CpunIR75q1/CpunIR8a receptor complex was strongly tuned to the green leaf volatiles trans -2-hexen-1-ol and trans -2-hexenoic acid. Mated females showed robust electroantennogram (EAG) responses and oviposition avoidance to both compounds. Crucially, CRISPR/Cas9-mediated knockout of CpunIR75q1 significantly reduced female EAG responses and abolished oviposition avoidance. These findings demonstrate that CpunIR75q1 mediates mating-induced oviposition avoidance, providing a molecular target for developing semiochemical-based pest management strategies.