Butterflies and Moths of North America

collecting and sharing data about Lepidoptera

Sylvan Hairstreak
Satyrium sylvinus (Boisduval, 1852)


Family: Lycaenidae
Subfamily: Theclinae
Identification: With or without tails. Upperside gray-brown or reddish with blue sheen; hindwing with small orange patch at lower edge. Female with yellowish tinge. Underside pale gray to white. Postmarginal band of small black dots; some individuals may have only a few spots. Yellow to red spot at hindwing lower edge.
Wing Span: 1 - 1 3/8 inches (2.5 - 3.5 cm).
Life History: Males perch on low vegetation near host plants to watch for females. Eggs are laid singly on stems of host plants where they hibernate until spring. Caterpillars feed on leaves.
Flight: One flight from May-August.
Caterpillar Hosts: Various willow (Salix) species.
Adult Food: Nectar from flowers including milkweed and Indian hemp.
Habitat: Willow thickets, open woodlands, streams, oases.
Range: British Columbia southeast to Wyoming, Colorado, New Mexico; south through California to Baja California Norte.
Conservation: Not usually required.
NCGR: G4 - Apparently secure globally, though it might be quite rare in parts of its range, especially at the periphery.
Management Needs: None reported.
Comments: NULL
Alternate Scientific Names:
Satyrium sylvinum
Get your BAMONA Gear!

Hoodies and t-shirts in two designs!


Advertise with us!

Do you have a product or service that you think would interest BAMONA users? If you would like to advertise on this website, contact us by email, or use the contact form and select the "Advertising" category.