Bug FAQLustrous Copper
Lycaena cupreus · Order: Lepidoptera · Family: Lycaenidae
The lustrous copper is a small butterfly with a wingspan of about 23 to 30 mm. It lives in the western mountains of North America and belongs to the Lycaenidae family. Adults fly from mid-June through July or August, feeding on nectar from thistles, alfalfa and sweet clover, while the larvae eat mountain sorrel and dock plants.
Source: Wikipedia
Size
The wingspan ranges from 23 to 30 mm.
Source: Wikipedia
What it eats
Adults sip nectar from Cirsium, Medicago sativa and Melilotus species.
Source: Wikipedia
When you see it
The flight period spans mid-June through August.
Source: Wikipedia
Where it comes from
Its native range is the western mountains of North America.
Source: Wikipedia
Where it is found in the US
Recorded in 12 of 51 states and DC. Most records: California, Idaho, Colorado, Wyoming, Oregon, Montana, Utah, Washington.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
When are lustrous copper butterflies active?
Adults fly from mid-June through July or August.
Source: Wikipedia
What do the larvae eat?
Larvae feed on mountain sorrel (Oxyria digyna) and dock (Rumex) species.
Source: Wikipedia
What plants do the adults visit for nectar?
Adults sip nectar from thistles, alfalfa and sweet clover (Cirsium, Medicago sativa, Melilotus).
Source: Wikipedia
Same family (Lycaenidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Lycaena_cuprea
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-24.