Variation in leaf resin composition between parent tree and progeny in Hymenaea: Implications for herbivory in the humid tropics

Variation in the sesquiterpene hydrocarbon leaf resins in the tropical leguminous genus Hymenaea is compared between parent tree, seedling and sapling progeny. Relatively large discrete quantitative variation in the leaf resins, known experimentally to display little phenotypic plasticity, has been classified into Compositional Types. Differences in Compositional Types in the leaves between parent tree and their seedling and sapling progeny are more pronounced in rain forest and related eocystems than in savanna and dry forests. A model is presented in which it is suggested that this variation in leaf resin may play an important role in defence against lepidopteran herbivores and thus also in seedling establishment under Hymenaea parent trees in rain forest and related ecosystems.