Caterpillar attack, caterpillar oral secretions (OS), insect-derived elicitors, such as volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] present in armyworm (Spodoptera sp) OS, are activators of induced volatile emission in corn (Zea mays) seedlings. This induced plant response can function as an indirect defense where parasitoids and other natural enemies use the volatile plant signals to locate potential hosts and prey. Recent research on phytohormone signal transduction cascades suggests that a combination of caterpillar-derived elicitors may be required to accurately reproduce plant responses to insect herbivory. Using the fall armyworm (Spodoptera frugiperda) as a model system, a further examination of volatile-inducing factors has been initiated. Progress on the separation and purification of a new class of insect-derived elicitors will be discussed.