Butterflies and Moths of North America

collecting and sharing data about Lepidoptera

Reakirt's Blue
Echinargus isola (Reakirt, [1867])


Family: Lycaenidae
Subfamily: Polyommatinae
Identification: Upperside of male light blue with darker veins and dusky border; female darker. Underside of forewing with postmedian row of 5 round black spots circled with white.
Wing Span: 3/4 - 1 1/8 inches (2 - 2.9 cm).
Life History: Males patrol for females with an erratic flight during daytime. Females lay eggs singly on flower buds of host during midday. Caterpillars eat flowers and seedpods, sometimes leaves; and are tended by ants which presumably protect the caterpillars in return for their sugary secretions.
Flight: All year in South Texas; 3 broods from March-November in the remainder of its residential range; migrates north once each year after hibernating in the south.
Caterpillar Hosts: Many plants in the pea family (Fabaceae) including yellow sweet clover (Melilotus officinalis), rattleweed (Astragalus), mesquite (Prosopis), indigo bush (Dalea), mimosa (Albizia), and indigo (Indigofera) species.
Adult Food: Flower nectar from a variety of herbs including spearmint and white sweet clover.
Habitat: Grasslands, fields, desert, meadows, weedy areas, creeksides.
Range: Resident from southern California, the Southwest, and Texas through Mexico and Central America to Costa Rica. Summer migrant north and east through the Mississippi River states to Wisconsin and Ohio.
Conservation: Not required.
NCGR: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management Needs: None reported.
Comments: NULL
Alternate Scientific Names:
Hemiargus isola