International audienceCoexistence of female colour morphs in animal populations is often consideredthe result of sexual conflict, where polymorphic females benefit from reduced male sexualharassment. Mate-searching males easily detect suitable partners when only one type offemale is present, but become challenged when multiple female morphs coexist, whichmay result in frequency-dependent mate preferences. Intriguingly, in damselflies, onefemale morph often closely resembles the conspecific male in body coloration, which haslead to hypotheses regarding intra-specific male-mimicry. However, few studies havequantitatively evaluated the correspondence between colour reflectance spectra from malesand male-like females, relying instead on qualitative visual assessments of coloration.Using colour analyses of reflectance spectra, we compared characteristics of the bodycoloration of ontogenetic male and female colour morphs of the damselfly Ischnura elegans.In addition, we evaluated whether males appear to (1) discriminate betweenimmature and mature female colour morphs, and (2) whether male-like females experiencereduced male mating attention and low mating frequencies as predicted fro