Multitrophic interactions between plants, herbivores and their carnivorousnatural enemies mediated by infochemicals

摘要

In recent years, considerable advances have been made in understanding the mechanisms of communication between plants, herbivores and their carnivorous enemies. Chemicals conveying information between these different trophic levels are called infochemicals (or semiochemicals). They are emitted by one organism and received by another. The receiver then shows a typical behavioural response or sometimes a physiological change. If both the signaler and the receiver benefit from the exchange of information, the infochemical is called a synomone, ifthe signaler alone benefits, it is called an allomone, and if the receiver alone benefits, a kairomone (Fig. 1). Intensive studies on these interactions (Fig. 1) will reveal novel mechanisms that may be useful for improved strategies in biological control. The discovery that plants respond to herbivore feeding by producing specific volatiles that attract carnivorous enemies (e. g., TAKABAYASHI and DICKE 1996) is a typical example. These plant synomones are in many cases systemically produced. The communicative interactions in different systems were studied by four research groups, the results of which are summarized below.