Diterpene acids are a significant component of conifer oleoresin, a viscous mixture of terpenoids composed of monoterpenoids, sesquiterpenoids and diterpenes.In the chemical ecology point of view the monoterpenes and sesquiterpenes, due to their importance in the semioehemistry of plant-insect interactions (host finding/selection), have been studied in more detail than the diterpene resin acids.However, the diterpene acids have also been referred as important defense compounds against insect pests and pathogens in conifers with greater importance in the insect performance after host colonization.