Production of complementary defense metabolites reflects a co-evolutionary arms race between a host plant and a mutualistic bark beetle-fungal complex

To assessing the effects of monoterpene profiles of different populations of lodgepole pine on the Mountain pine beetle-Grosmannia clavigera complex. We first sampled 9-10 individual trees from each of 40 pine families from a progeny trial and characterized monoterpene profiles of each family. We then grouped these families in four chemotypically different clusters (or chemotypes) using cluster analysis and selected representative families from each cluster. Next, we tested beetle-fungal responses in plant-based media amended with synthetic monoterpene profiles that emulated the selected families. Our objective was to determine how the constitutive monoterpene profiles of mature lodgepole pine trees affect host acceptance by MPB and growth of G. clavigera.