Hemiargus blue

The Reakirt's Blue (Hemiargus isola) is a butterfly of the Lycaenidae family. It is found in Central America and the extreme southern U.S., isola migrates regularly throughout most of the U.S. almost to the Canadian border, and very rarely into the southern Prairies.
The wingspan is 16–23 mm. Adults are on wing from June to SOctober in the north and all year round in south.
The larva feed on Fabaceae, particularly mesquites (Prosopis spp.)