Synonyms and other taxonomic changes
Echinargus isola (Reakirt)
Orig. Comb: Lycaena isola Reakirt, 1867
Syn: Hemiargus isola (Reakirt)
Upper side of male is blue with brownish margin, and with one prominent and usually one or two tiny blackish spots near the hind angle of the hind wing. Females similar above, but mostly brownish (bluish toward base of wings and on body), and with dark spots usually more prominent and bordered pale. Below with most dark spots grayish or brownish, rimmed white, but with the postmedian row on the front wing, and a few on the disc of th hind wing prominent, blackish, and round to oval; prominent dark eye spots near hind angle of hind wing with metalic scaling.
Hemiargus ceraunus is commonly found together with E. isola and is the species most likely to be confused. In H. ceraunus the postmedian spots on the front wing below are grayish or brownish, and are usually more rectangular than round. Distinguishing the two species by looking at the upper side alone can be very difficult, but where they are found together females of H. ceraunus often (not always) have more blue color, while the dark border on males is often (not always) darker and more contrasting. There is more often only one dark spot near the hind angle, and it is often faded looking and sometimes entirely missing (but the corresponding eye spots are present on the under side).
w US, CA-TX-WS / Mex. to C. Amer. - Map
Larva use many genera and species in the Legume Family - Fabaceae. Adults are often found nectaring at flowers and visiting mud.
Multiple broods as long as weather allows; year-round in the far south; probably from one to three broods in the north, depending upon arrival time of first strays from the south each year.
Often one of the most abundant species of butterflies throughout the Southwest, but sometimes not noticed due to its small size.