Butterflies and Moths of North America

collecting and sharing data about Lepidoptera

Gray Hairstreak
Strymon melinus (Hübner, 1818)


Family: Lycaenidae
Subfamily: Theclinae
Identification: One tail on hindwing. Upperside blue-gray with large red spot near tail. Underside of spring/fall form is dark gray, summer form is paler gray. Relatively straight postmedian line is white, bordered with orange on the inside edge.
Wing Span: 7/8 - 1 3/8 inches (2.2 - 3.5 cm).
Life History: Males perch all afternoon on small trees and shrubs to seek receptive females. Eggs are laid singly on flowers of host plant. Young caterpillars feed on flowers and fruits; older ones may eat leaves. Chrysalids hibernate.
Flight: Two flights from May-September in the north, three-four flights from February-November in the south.
Caterpillar Hosts: Flowers and fruits from an almost endless variety of plants; most often from pea (Fabaceae) and mallow (Malvaceae) families including beans (Phaseolus), clovers (Trifolium), cotton (Gossypium), and mallow (Malva).
Adult Food: Nectar from many flower species including dogbane, milkweed, mint, winter cress, goldenrod, tick trefoil, and white sweet clover.
Habitat: Open, nonforested sites; common in disturbed, weedy areas.
Range: Throughout continental United States from southern Canada south to Mexico; southward to Venezuela. Comments: The most widespread hairstreak in North America.
Conservation: Not usually required.
NCGR: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management Needs: Caterpillars may cause economic damage to bean and cotton crops.
Comments: NULL