Angerona Hairstreak (Electrostrymon angerona)

One of three very similar hairstreaks I have seen, the angerona hairstreak may be identified by the black and white band that extends across the underside of both wings. It is most similar to the columella scrub-hairstreak (Strymon columella), but in that species the black and white band takes the form of a row of distinct spots. The hairstreaks have a habit of rubbing their hind wings together when alight, but I am have no idea why they like to do this.