Interactions between plants and plant-feeding insects are the most common and diverse forms of species interaction on earth. Understanding how traits and species evolve and diversify in these interaction networks is of fundamental importance for ecology and evolutionary biology. This proposal investigates the evolution of plant signaling traits in locally evolving networks of interacting species. I use two crucifer plant species (Arabidopsis lyrata and Arabis alpina), their generalist insect pollinators, and selected seed predators and herbivores as models. I will explore how spatial variation in plant mating system affects visual and chemical signaling patterns and the interactions between these plants and their associated insects. The project merges several different techniques and includes green-house experiments, field studies and molecular approaches. Novel components include: (i) a comparative approach of studying floral signaling evolution across multiple populations, mating systems, environments, and species; (ii) the simultaneous measurement of phenotypic selection on floral scent and visual signals in natural populations; and (iii) the assessments of functional importance for each signaling trait in the interaction with multiple associated insect enemies and mutualists. A funded project would serve as an important cornerstone in my research program, which studies how spatial and ecological complexity shapes the diversity of plant-insect interactions.