Female colour polymorphism is a widespread trait in Ischnura and has been linked to mating strategies, sexual conflict, and evolutionary diversification. In the Colombian Andes, Ischnura cyane and Ischnura capreolus occur in sympatry, and localities contain admixed/intermediate individuals. Here, we characterize female colour polymorphism, ontogenetic colour change, and pruinescence in I. cyane and individuals of admixed/intermediate morphology, within a comparative framework including I. capreolus. We evaluate mating-associated patterns using colour traits, operational sex ratio, and mating frequency observations, and we evaluate reproductive morphology. Our results show that both taxa are dimorphic, with androchrome and gynochrome females. In I. cyane, mating-associated traits were consistent with polyandry, whereas admixed/intermediate individuals exhibited patterns associated with monandry. Females of I. cyane and admixed/intermediate individuals cannot be distinguished based on colour traits or ontogenetic colour change, but they differ from I. capreolus. In contrast, males of the three populations are differentiated by caudal appendage morphology. No relationship was detected between male cercus size and female mesostigmal plate size among mating pairs. The coexistence of overlapping colour traits, asymmetric sexual differentiation, and contrasting mating-associated patterns supports the interpretation of an admixed system involving I. cyane and I. capreolus. Female colour polymorphism nevertheless remains conserved across contrasting mating-associated patterns in Andean Ischnura.
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Ríos et al. (2026) studied this question.