Calycopis isobeon
This was a species we found periodically during our time in south Texas. The blue color you can see in this image is from the dorsal surface of the wing on the far side away from the lens. Like many other lycaenid butterflies, dusky-blue groundstreaks rub their wings together to distract predators to their false antennae (tails, or hairstreaks) on the hindwings. If a predator attacks, they are likely to bite away part of a wing, allowing the butterfly to make its escape.