Sexual harassment is a common evolutionary outcome of sexual conflict of interest over mating, but we know little about the fitness consequences of harassment, how females have responded to it, or how species interactions have shaped responses by both females and males. Enallagma damselflies, whose females are either green or a male-like blue, appear to have evolved as a female response to male sexual harassment. My work focuses on testing the sexual harassment hypothesis, along with the costs and benefits to females of their sexual signalling, and male responses to such signalling. Ultimately I am interested in how sexual conflict in this system could lead to speciation in this group of NA odonates, many of which have speciated relatively recently, during interglacial periods.