The olfactory systems of insects can detect semiochemicals and transfer signals in complex environments, which can initiate specific behaviours in insects, such as searching for food, locating hosts, finding mates, selecting oviposition sites and avoiding enemies (Leal, 2013;Takken & Knols, 1999). Various olfactory proteins are involved in the chemoreceptive process in antennal sensilla, including odorant-binding proteins (OBPs), chemosensory proteins, odorant receptors, ionotropic receptors, sensory neuron membrane proteins and odorant-degrading enzymes (Vogt, 2003;Zhao et al., 2017;Zhou et al., 2004). Insect OBPs are small and water-soluble proteins that can transport specific chemicals to membrane-bound olfactory receptors (Brito et al., 2016). Based on amino acid sequences and expression patterns, lepidopteran OBPs are usually divided into three subfamilies: general odorant-binding proteins (GOBPs), pheromonebinding proteins and antennal binding proteins (Breer et al., 1990;

Korean pine is an economically essential afforestation species limited by the unreasonable collection of cones, indiscriminate use of chemical pesticides and pest damage. This study aimed to determine whether spraying bacterial or fungal solutions affected insect pests, cone development, and the seed quality of Korean pine Pinus koraiensis Sieb. et Zucc. The experiment was conducted in a forest plantation in Linkou County (Heilongjiang, China) in 2019. Four fungal strains and one bacterial strain were applied during the flowering phase of Korean pine. The results after a year and a half of study indicated that a high concentration of Bacillus thuringiensis 223176 promoted cone development, increased seed weight, and reduced the proportion of damaged cones. Under this treatment, there were 15.873% damaged cones; the seed weight reached 0.829 g, and there were 82.738% fully developed cones. Trees treated with the second most effective strain, Beauveria bassiana 122077, had 30.556% damaged cones and an average seed weight of 0.810 g. Leucanicillium antillanum 01 performed the worst in this study. The seed weight was only 0.775 g, and the damaged and fully developed cones were 52.444 and 41.773%, respectively. In summary, spraying bacterial or fungal solutions during the flowering stage of Korean pine positively impacted seed quality and effectively decreased damage by the lepidopteran species that feed on the cones and seeds in this study.