Chemical Communication between Phytopathogens, Their Host Plants and Vector Insects and Eavesdropping by Natural Enemies

Evolutionary adaptations in plant, microorganism and arthropod interactions are primarily studied in systems involving only two of these groups: plants and microbes, plants and arthropods, or arthropods and microbes (Biere and Tack, 2013). Beside this, it was stated recently that there is emerging evidence that three-way interactions between plants, arthropods andmicroorganisms can play a major role in shaping ecological communities (Tack and Dicke, 2013). Moreover, the study of three-way interactions should not only include the mediation of plant-arthropod interactions by arthropod associated microorganisms or mutualistic plant associated microbes as proposed by Biere and Tack (2013), but should also include plant pathogens and arthropod antagonists (predators and parasitoids). Unfortunately, to date little is known about the influence of plant pathogens on the third trophic level. Thus, in this commentary the importance of a multitrophic research approach covering more than three-way interactions, as it was studied recently by Martini et al. (2014), is highlighted.