Dioryctria rubella and Dioryctria yiai : Identification of Chemosensory‐Related Genes and Preliminary Functional Analysis of Odorant Binding Proteins

Dioryctria rubella Hampson and Dioryctria yiai Mutuura & Munroe are two closely related species that infest Pinus plants. Due to their highly overlapping ecological niches, existing trapping techniques often lack sufficient specificity for effective distinction and control. Thus, elucidating the molecular mechanisms of their olfactory recognition systems has become a crucial breakthrough for improving management efficiency. In this study, antennal transcriptome sequencing led to the identification of 16 odorant binding proteins (OBPs), 1 pheromone binding protein (PBP), 12 chemosensory proteins (CSPs), 36 odorant receptors (ORs), 8 gustatory receptors (GRs), 9 ionotropic receptors (IRs) and 2 sensory neuron membrane proteins (SNMPs) in D. rubella . For D. yiai , we identified 20 OBPs, 2 PBPs, 12 CSPs, 33 ORs, 5 GRs, 9 IRs and 4 SNMPs. Phylogenetic analysis revealed that the olfactory‐related proteins of both species are highly conserved and largely cluster with those of other related moths such as Dioryctria abietella Denis & Schiffermüller and Conogethes punctiferalis Guenée. Based on both sex‐biased and species‐specific expression patterns, four key proteins—DrubPBP, DyiaPBP1, DrubOBP5, and DyiaOBP4—were selected for structural prediction using AlphaFold3 and molecular docking. The results indicated that the host volatile caryophyllene stably binds to OBPs of both species via hydrophobic interactions, suggesting a synergistic role in host location. The PBP of D. rubella exhibited stronger binding affinity to its five sex pheromone components— Z ‐11‐hexadecenal, Z ‐11‐hexadecenyl acetate, E ‐11‐hexadecenal, Z , E ‐9,11‐tetradecadienyl acetate, and E ‐9‐tetradecenol—compared to that of D. yiai ; however, DyiaPBP1 showed relatively higher affinity specifically for Z , E ‐9,11‐tetradecadienyl acetate compared to the other four pheromone components, which may explain the observed cross‐trapping phenomenon. This study provides the first systematic identification of chemosensory genes in these two moth species, clarifies the molecular basis of cross‐trapping, and offers key theoretical support for the development of targeted attractants or inhibitors. Furthermore, it establishes a technical framework for deciphering olfactory mechanisms and developing green control strategies against forest pests.