The insects that feed on reproductive structures of forest trees are not only economically important, they are fascinating examples of the ability of insects to adapt to and exploit the many niches available in forest ecosystems. Cones, fruits, seeds, nuts, catkins and pollen are rich food sources available to insect herbivores. These reproductive structures are qualitatively and quantitatively different from vegetative parts of the tree, in terms of food quality, spatial and temporal distribution, and plant protective strategies. In this chapter we will explore types of reproductive structure herbivory, nutritive value and host defenses, insect strategies and community structure, evolutionary consequences for the host, and implications for management.