The conspicuousness contradiction: brighter males have lower mating chances in the damselfly Argia hasemani but not in Argia croceipennis

In odonates, male coloration is often more conspicuous than female coloration. This difference is frequently attributed to the role of male colour in male–male competition to access females. However, there are sexually dimorphic odonate species, such as the damselflies Argia hasemani and Argia croceipennis, in which male–male interactions are much less intense. In these species, it might be that male coloration affects male success directly when interacting with females. Therefore, we hypothesized that males with more intense coloration present higher copulation success. To investigate this hypothesis, we registered which males copulated in the field during 4 days and estimated the coloration of all observed males in the female visual spectrum. Surprisingly, we found that dull males had higher chances of copulation in A. hasemani, whereas in A. croceipennis male coloration did not influence the chances of copulation. Our data also indicated that brighter males of A. hasemani were also more conspicuous to potential avian predators, whereas this was not the case in A. croceipennis. We suggest that females of A. hasemani might avoid brighter males owing to increased risk of predation during copulation.