Mistakes in sexual recognition among sympatric Zygoptera vary with time of day and color morphism (Odonata: Coenagrionidae)

Abstract

Abstract In odonates, female specific color polymorphisms appear to be an evolutionary response to sexual harassment, but we know little about the decision rules males use when searching for variable females. For two sympatric species of Enallagma, we measured male responses to live female variants under field conditions, early and later in the day. In the morning, when the operational sex ratio was the most male-biased and female density the lowest, males of the polymorphic E. civile did not discriminate among conspecific female morphs, and reacted sexually to the andromorphic females of E. aspersum, a monomorphic species. ‘Then, male E. aspersum did not favor conspecific females over E. civile morphs. Both morph types were more confusing for males than were conspecific male signals. However, after 13:00 h, males of both species made few mistakes, and E. civile males reacted sexually relatively less often to conspecific andromorphs, the minority morph in this population. The changes in a male's sexual re...