Echinargus isola, or Reakirt's blue, is a butterfly of the family Lycaenidae. It is the sole representative of the monotypic genus Echinargus. It is found in Central America and the extreme southern U.S. Echinargus isola migrates regularly throughout most of the U.S. almost to the Canada–United States border, and very rarely into the southern prairies.
- Echinargus isola isola
- Echinargus isola alce (Edwards, 1871) (Colorado)
- Reakirt's Blue, Butterflies of Canada