Chalk-hill Blue
Lysandra coridon

The chalkhill blue is a butterfly in the family Lycaenidae. It is a small butterfly that can be found throughout the Palearctic realm, where it occurs primarily in grasslands rich in chalk. Males have a pale blue colour, while females are brown. Both have chequered fringes around their wings. Source
Where it is now
In the last 8 weeks this insect was recorded 11 times across 2 areas (each area is a 5 degree square).
See the Chalk-hill Blue on the live map
Arrival dates
The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.
| Region | First arrival | Last arrival | Typical peak | Areas |
|---|---|---|---|---|
| Europe | 29 June 2026 | 13 July 2026 | 24 August 2026 | 3 |
Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.