CHEMICAL ECOLOGY FROM GENES TO COMMUNITIES Integrating ‘omics’ with community ecology

Chemical cues that convey information are widely used by living organisms. The cues mediate interactions in food webs as well as non-trophic interactions such as interactions between conspecific organisms or between plants and natural enemies of herbivorous organisms. Communities are composed of food webs and each food web is overlaid with a reticulate infochemical web that is more complex than the underlying food web. Chemical ecology has addressed the role of information conveyance in intraspecific and interspecific interactions and has mostly concentrated on elucidating the identity of chemicals and their role in individual interactions of food webs. In addition, the role of infochemicals has been investigated in multitrophic interactions. Recently, several exciting developments have taken place. On the one hand, chemical ecologists more and more address molecular mechanisms underlying the production of infochemicals and the responses to the cues, such as signal transduction and gene expression. On the other hand, studies on the role of infochemicals in population and community ecology have been initiated. These developments are not independent of each other, and knowledge of mechanisms will provide important tools for investigating the role of infochemicals in populations and communities. This will be discussed especially in the context of insect–plant communities.