I’ve stared at this one many times, and was stumped. It sure looks like a Gray Hairstreak female: Orange antennae tips, gray abdomen, wings held open, tails, orange on head, that orange spot with the black spot at its outer margin, but . . . those blue spots along the outer margins of the hindwings??
I sought feedback from Mike Rickard for the ID of another Lower Rio Grande Valley butterfly (The Cassius Blue) and along the way, he suggested I visit the website, Welcome To Butterflies Of America. I did, and Mike was right, that website is a big help when you want to ID a butterfly.
This one here is typical of Gray Hairstreaks in Texas, what with those blue spots winking at you. So this is of the Strymon Melinus Franki subspecies, and I love those blues, I do.