Bug FAQSilver-studded Blue
Plebejus argus · Order: Lepidoptera · Family: Lycaenidae
The Silver-studded Blue is a small blue butterfly with distinctive silver spots on its hindwings and a dark blue upper side edged in black. It lives on heathland, mossland and calcareous grassland across Europe and the Palearctic, feeding on nectar as an adult and on legume plants as a larva.
Source: Wikipedia
How to recognize it
The wings are bright blue with a black rim, white edges and silver spots on the hindwings. The upper side is a deep dark blue with a broad black border, similar to Reverdin's blue. Males and females differ in wing colour.
Source: Wikipedia
Size
It is generally smaller than the related species Plebejus argyrognomon.
Source: Wikipedia
Where it lives
It inhabits heathland, mossland and limestone (calcareous) grassland.
Source: Wikipedia
What it eats
Adults feed on flower nectar.
Source: Wikipedia
Life cycle
The butterfly goes through four stages: egg, larva, pupa and adult. In the south there are two generations per year, while the north typically has one.
Source: Wikipedia
When you see it
Adults emerge from late June to early July and fly until early August.
Source: Wikipedia
Where it comes from
Its range extends across Europe and eastward through the Palearctic region.
Source: Wikipedia
Lookalikes
It looks much like Reverdin's blue (Plebejus argyrognomon).
Source: Wikipedia
Where it is found in the US
Recorded in 8 of 51 states and DC. Most records: Colorado, California, Washington, Idaho, Utah, Oregon, Wyoming, Montana.
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
Are they a garden pest?
They feed on nectar and on some legume plants as larvae, but no source says they damage crops or gardens.
Source: Wikipedia
Same family (Lycaenidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Silver-studded_blue
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.