Bug FAQSwiss Brassy Ringlet
Erebia tyndarus · Order: Lepidoptera · Family: Nymphalidae
The Swiss brassy ringlet is a mid-sized butterfly with a wingspan of about 35 mm. It lives above the treeline in alpine meadows from 1,200 to 2,700 m in the Alps of several European countries. Adults appear briefly in July and August, feeding on nectar from yellow mountain flowers.
Source: Wikipedia
How to recognize it
The upper wings are dark brown with a brassy green-gold sheen on the forewings. A coppery or orange patch near the tip of the forewing and along the outer margin of the hindwing contains black eyespots with white centers. The underside is a cryptic light grey-brown, with a darker arched band on the hindwing that has a silvery sheen.
Source: Wikipedia
Size
Wingspan is roughly 35 mm.
Source: Wikipedia
What it eats
Adults sip nectar from yellow mountain flowers in summer. Caterpillars feed on grasses such as sheep's fescue, matgrass, and other fescues and meadow-grasses.
Source: Wikipedia
Life cycle
Eggs are green, oval, and ribbed longitudinally. Pupae are thick and brown; they overwinter on the ground and pupate in May to June.
Source: Wikipedia
When you see it
Adults are on the wing only in July and August.
Source: Wikipedia
Where it comes from
Native to the European Alps, occurring in France, Italy, Germany, Switzerland, Liechtenstein, and parts of Austria.
Source: Wikipedia
Lookalikes
The cryptic light grey-brown underside and the silvery-sheened hindwing band are also seen in related Erebia species.
Source: Wikipedia
Where it is found in the US
Recorded in 7 of 51 states and DC. Most records: Colorado, Wyoming, Utah, Montana, Kansas, New Hampshire, Texas.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
When can I see the Swiss brassy ringlet?
Adults fly for a short period in July and August.
Source: Wikipedia
What do the caterpillars eat?
They feed on various grasses, especially sheep's fescue, matgrass, and other fescues and meadow-grasses.
Source: Wikipedia
Where does this butterfly live?
It inhabits alpine meadows above the treeline at 1,200 to 2,700 m in the European Alps.
Source: Wikipedia
Same family (Nymphalidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Erebia_tyndarus
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.