Plant-herbivore interactions are the conduit for energy flow from the sun to the diversity of life on the planet. Understanding the genetic and chemical mechanisms underlying these interactions inform fundamental biological principles and hold the key for solving applied problems. Recent advances show that plant-herbivore interactions are at the center of networks of diverse communities, with the macroevolution of chemical defense a driver of plant and herbivore diversity. Variability in defenses affects antagonistic and mutualistic interactions, many of which are relevant for conservation. At the same time, sensory biology of herbivores operates at different spatial scales, with consequences for the effects of plant resistance in communities and in pest management applications. With each decade we are getting closer to understanding the genetic basis of adaptation, and current work in plant-herbivore interactions is revealing surprising rules that govern evolution in ecological communities. The meeting will incorporate the interactions between plants and their vertebrate and invertebrate herbivores, including pollinators and seed dispersers, and associated microbes across wild and human dominated systems. Sessions will highlight diverse speakers with diverse approaches to stimulate discussion about paths to push the discipline forward. The 15th Gordon Research Conference on Plant-Herbivore Interactions (GRC PHI) will cover a wide range of topics, including sensory biology by plants and herbivores across scales, evolution of plant defenses, multispecies interactions, applications to pest management and climate change, and how new tools are changing our discipline.