Identification, Expression Patterns, and Functional Characterization of Chemosensory Proteins in Dendroctonus armandi (Coleoptera: Curculionidae: Scolytinae)

Abstract

The Chinese white pine beetle, <i>Dendroctonus armandi</i> Tsai and Li (Coleoptera: Curculionidae: Scolytinae), is a serious pest of coniferous forests in China. Thus, there is considerable interest in developing eco-friendly pest-control methods, with the use of semiochemicals as a distinct possibility. Olfaction is extremely important for fitness of <i>D. armandi</i> because it is the primary mechanism through which the insect locates hosts and mates. Thus, here we characterized nine full-length genes encoding chemosensory proteins (CSPs) from <i>D. armandi</i>. The genes were ubiquitously and multiply expressed across different developmental stages and adult tissues, indicating various roles in developmental metamorphosis, olfaction, and gustation. Ligand-binding assays implied that DarmCSP2 may be the carrier of <i>D. armandi</i> pheromones and various plant host volatiles. These volatiles were identified through RNA interference of <i>DarmCSP2</i> as: (+)-α-pinene, (+)-β-pinene, (-)-β-pinene, (+)-camphene, (+)-3-carene, and myrcene. The systematic chemosensory functional analysis of DarmCSP2 in this study clarified the molecular mechanisms underlying <i>D. armandi</i> olfaction and provided a theoretical foundation for eco-friendly pest control.