Bug FAQSylvan Hairstreak
Satyrium sylvinus (formerly Strymon sylvinus) · Order: Lepidoptera · Family: Lycaenidae
The sylvan hairstreak is a small butterfly with a wingspan of about 25 to 30 mm. It lives in western North America, from British Columbia through the western United States down to Baja California Norte, Mexico. Its caterpillars feed on willow leaves and the species overwinters as an egg.
Source: Wikipedia
How to recognize it
The sylvan hairstreak belongs to the Lycaenidae family of butterflies.
Source: Wikipedia
Size
Adults have a wingspan ranging from 25 to 30 mm.
Source: Wikipedia
What it eats
The larvae eat the leaves of willow (Salix) species.
Source: Wikipedia
Life cycle
The species spends the winter as an egg before hatching into caterpillars.
Source: Wikipedia
Where it comes from
Its native range covers western North America, including British Columbia, the western United States and northern Baja California, Mexico.
Source: Wikipedia
Where it is found in the US
Recorded in 14 of 51 states and DC. Most records: California, Washington, Idaho, Oregon, Utah, Montana, Colorado, Wyoming.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What do sylvan hairstreak caterpillars eat?
The caterpillars feed on the leaves of willow (Salix) species.
Source: Wikipedia
Same family (Lycaenidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Satyrium_sylvinus
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-24.