When plants are attacked by arthropod herbivores they actively emit volatile substances that attract natural enemies of the herbivores. It is generally assumed that these herbivore-induced volatiles function as indirect defense signals and several field studies have provided evidence that the volatiles contribute to enhanced mortality of herbivores. Yet, skepticism persists among some scientists concerning the benefits that the plants derive from attracting natural enemies, especially where it concerns the attraction of parasitoids. It is also often criticized that the function of herbivore-induced volatiles is mostly studied in systems that involve cultivated plants and natural systems have rarely been investigated. For the current project we will study the plant teosinte and associated insects in their natural environment in Mexico. Teosinte is the wild ancestor of maize and maize is the best-studied plant in the context of tritrophic interactions. We will use our knowledge of the genetic and chemical mechanisms of these interactions in the cultivated system to study the same interactions in teosinte in order to address our general hypothesis that inducible volatiles attract parasitoids and thereby reduce herbivore damage and increase plant fitness. The aim is to provide the first evidence from nature for the adaptive role of volatile plant signals in recruiting natural enemies of herbivores.