AbstractLeptocybe invasais an insect pest causing gall formation on oviposited shoot tips and leaves ofEucalyptustrees leading to leaf deformation, stunting, and death in severe cases. We previously observed different constitutive and induced terpenes, plant specialized metabolites that may act as attractants or repellents to insects, in a resistant and susceptible clone ofEucalyptuschallenged withL. invasa. We tested the hypothesis that specific terpenes are associated with pest resistance in aEucalyptus grandishalf‐sib population. Insect damage was scored over 2 infestation cycles, and leaves were harvested for near‐infrared reflectance (NIR) and terpene measurements. We used Bayesian model averaging for terpene selection and obtained partial least squares NIR models to predict terpene content andL. invasainfestation damage. In our optimal model, 29% of the phenotypic variation could be explained by 7 terpenes, and the monoterpene combination, limonene, α‐terpineol, and 1,8‐cineole, could be predicted with an NIR prediction ability of .67. Bayesian model averaging supported α‐pinene, γ‐terpinene, and iso‐pinocarveol as important for predictingL. invasainfestation. Susceptibility was associated with increased γ‐terpinene and α‐pinene, which may act as a pest attractant, whereas reduced susceptibility was associated with iso‐pinocarveol, which may act to recruit parasitoids or have direct toxic effects.