Species do not live alone but interact and rely strongly on each other. Species also show a strong spatially structured distribution. Population dynamics, dispersal, and environmental change impact fitness, and the subsequent hereditary changes of individual traits. Evolutionary changes conversely impact population dynamics. These eco-evolutionary processes are therefore central to the functioning of populations and the maintenance of biodiversity. To understand the functional importance and relevance of these eco-evolutionary dynamics in nature, we need to gradually add new dimensions to our empirical research, a challenging endeavour. Here, we propose the highly needed next step for our understanding of the evolution of trophic interactions in relation to variation in spatial structure. We will integrate genetic-molecular-biochemical work, experimental metapopulations and modeling, using a highly tractable clover-mite (plant-herbivore) interaction. The project will provide answers to the question how co-evolutionary processes affect the population dynamics of the interacting species, and how changes in connectivity but also environmental variation along an urbanisation gradient affect their overall performance and stability in metapopulations.