Insects employ a variety of chemical cues to find and identify resources. We study two model systems, moth communication by pheromones and orientation by female mosquitoes to odors from prospective hosts. Some of our work with moths is aimed at understanding mechanisms and evolutionary forces mediating these odor-mediated behaviors, and includes documenting within species variation in pheromone production and response, and using measurements of heritability and selection experiments to determine the genetic architecture of pheromone production and response. With mosquitoes our efforts are directed at understanding how host-emitted odors influence orientation from a distance and landing on the host, and how repellents interfere with these behaviors. Our work on odor-mediated orientation includes investigation of dispersal of odor plumes in wind, the role of plume structure in orientation, and the integration of visual and odor inputs in modulating orientation. Many of these studies employ wind tunnels where we can manipulate the sensory inputs and record maneuvers with 3-D video. We also study the use of formulated synthetic pheromone to disrupt mating of moth pests.