Abstract: In many species of insects males occupy and defend perching sites where they sit and wait for females. Passing females are detected visually and male fly up quickly to intercept and court them. Understanding the mechanisms by which males detect mates involves integrating information about the behavior of females, the optics and morphology of the eye, and how the visual system is preferentially positioned in space. I will outline our current understanding of this system in a butterfly an its implications for the interactions between morphology, behavior, and ecology in both immediate and evolutionary time scales. A number of navigational issues arise in this system that will hopefully be of interest to the group.