Satyrium sylvinum

The Sylvan Hairstreak (Satyrium sylvinum) is a butterfly of the family Lycaenidae. It is found in western North America,[1] from British Columbia south-east to Wyoming, Colorado and New Mexico and south through California to Baja California Norte.

Sylvan Hairstreak
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Lycaenidae
Genus:	Satyrium
Species:	S. sylvinum
Binomial name
Satyrium sylvinum (Boisduval, 1852)[1]
Synonyms
Thecla sylvinus Boisduval, 1852 Satyrium sylvinus Thecla dryope Edwards, 1870 Thecla putnami H. Edwards, 1877 Thecla putnami Scudder, 1876 Thecla itys Edwards, 1882 Strymon sylvinus desertorum Grinnell, 1917

The wingspan is 25–30 mm. There are specimens with or without tails. The upperside is grey-brown or reddish with a blue sheen. The hindwings have a small orange patch at the lower edge. Females have a yellowish tinge. The underside is pale grey to white. There is a postmarginal band of small black dots. Some individuals may have only a few spots. There is also a yellow to red spot at the lower edge of the hindwing. Adults are on wing from May to August in one generation per year. They feed on the nectar of various flowers, including milkweed and Indian hemp.

The larvae feed on the leaves of Salix species.[2] The species overwinters as an egg.