Plant-mediated Aboveground-belowground Interactions: the Spider Mite Perspective

Research on aboveground-belowground interactions has recently experienced a boost. In spite of the relative prosperity of scientific literature featuring aboveground herbivorous arthropods involved in abovegroundbelowground interactions, mites have so far been under-represented. To stimulate work with mites in this area, we summarize existing research on plant-mediated interactions of aboveground herbivorous mites and belowground plantassociated organisms. A literature search revealed 17 studies dealing with plant-inhabiting mites, all of which involve the two-spotted spider mite Tetranychus urticae. We categorize the studies according to the belowground biota associated with the mite’s host plants, summarize the observed effects of the belowground biota on the aboveground mites and discuss possible interaction mechanisms. The paucity of existing studies does not yet allow to draw general conclusions but it is apparent that these aboveground-belowground interactions are strongly context-dependent and vary among plant species and species of belowground biota. In conclusion, we argue that the wealth of knowledge on the behavior, ecology, physiology, and genetic make-up of T. urticae and its natural enemies, and their suitability for laboratory rearing and experimental studies at various spatial scales and organizational levels, make these plant-inhabiting mites perfectly-suited model organisms for future research on aboveground-belowground interactions.