Bug FAQChalkhill Blue
Polyommatus coridon · Order: Lepidoptera · Family: Lycaenidae
Also called: Chalk Hill Blue
The Chalkhill Blue butterfly has a wingspan of about 30 to 36 mm. It lives on dry, calcareous grasslands with short, flowering vegetation, from low to high elevations. Its range covers most of central and western Europe and parts of the Palearctic realm.
Source: Wikipedia
How to recognize it
Females show a dark brown upper wing surface with orange edge spots and a chequered fringe.
Source: Wikipedia
Size
Wingspan ranges from 30 to 36 mm (1.2 to 1.4 in).
Source: Wikipedia
Where it lives
Prefers dry, calcareous grasslands at 100 to 2,000 m altitude. Favors short grass areas rich in flowering plants.
Source: Wikipedia
What it eats
Adults feed on plants such as Hippocrepis, Coronilla, Astragalus, and Vicia until June. They are visited by the ant Formica flava, attracted to a dorsal gland.
Source: Wikipedia
Life cycle
The pupa is slender, smooth, dirty-yellowish brown with a dark dorsal line and rests on the ground, often under stones.
Source: Wikipedia
When you see it
Adults are on the wing from June through August, being common in some locales and rare in others.
Source: Wikipedia
Where it comes from
Also occurs in the western and southern parts of the Palearctic, including Asia Minor and the south Urals.
Source: Wikipedia
Lookalikes
Like many blues, it is distinguished from similar species by the pattern on the underside of the wings. Various aberrations occur frequently.
Source: Wikipedia
More photos
Same family (Lycaenidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Chalkhill_blue
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 2026-10-22.