Abstract: This paper comprehensively reviews the research progress on 2 bark beetle species across multiple aspects, including semiochemicals, olfactory sensilla, odorant-binding proteins (OBPs), and odorant receptors (ORs). Specifically, it provides a detailed synthesis of: the behavioral regulation mechanisms mediated by semiochemicals, the diversity and differentiation between olfactory sensors and semiochemicals, and the tripartite interactions among OBPs/ORs, semiochemicals, and behavioral responses. We further propose a framework for decoding the olfactory interplay between 2 species.