When damaged by herbivorous arthropods, plants are known to emit a blend of volatiles that have several ecological functions in nature. One of the well known functions is to attract carnivorous natural enemies of inflicting herbivores. Volatiles from infested plants are specific in terms of herbivore species and plant species. The carnivores are known to cope with such specificity by learning. The first part of this paper will show the learning behavior of parasitic wasps that attack aphids on bean plants. In the second part of this paper, we will focus on the multifunctional aspects of volatiles from plants that are either infested or intact. Our recent results on the tritrophic interaction of willow plants, willow leaf beetles and ladybirds showed that the volatiles from willow plants infested by leaf beetles mediated interactions between plants and leaf beetles, plants and ladybirds. Further, these interactions were affected by their physiological conditions, gender and developmental stages. Based on these data, we will discuss the interaction and information networks mediated by ecological volatiles.