| Family | Lycaenidae |
|---|---|
| Subfamily | Polyommatinae |
| Genus | Lysandra |
| Species | coridon |
| Authority | (Poda, 1761) |
| English Name | Chalkhill Blue |
| European Red List 2010 | Least Concern (LC) |
|---|---|
| EU 27 Red List 2010 | Least Concern (LC) |
| European Red List 2025 | Least Concern (LC) |
| EU 27 Red List 2025 | Least Concern (LC) |
| Habitats Directive | |
| Bern Convention | |
| CITES |
The Chalkhill Blue occurs on calcareous soil in dry, and flower-rich places with a short vegetation. They seem to prefer sheltered places. Sometimes, populations can be extremely large which is especially obvious in the late afternoon when the butterflies come together to roost. Hundreds of butterflies can be seen, their heads pointing downwards into the vegetation, wings upright, the light- coloured underwings gleaming in the evening sun. Horseshoe Vetch (Hippocrepis comosa) is its only foodplant, the female laying her eggs on the leaves. The eggs hibernate. The caterpillars are attended by ants of the genera Myrmica, Lasius, Formica, Plagiolepis, Tetramorium, Aphaenogaster, and Tapinoma. The Chalk-hill Blue pupates in the litter layer. It usually only has one generation a year. Lysandra hispanus (HERRICH-SCHÄFFER, 1851) – Provence Chalkhill Blue The Provence Chalkhill Blue occurs on dry, calcareous soils covered with a flower-rich grassy vegetation, often with scattered bushes. Eggs are laid on Horseshoe-vetch (Hippocrepis comosa). The caterpillars are attended by ants of the genera Plagiolepis and Crematogaster. The Provence Chalkhill Blue has two generations a year and the butterflies can be seen as late as October.
Albania / Andorra / Austria / Belarus / Belgium / Belgium: Flanders (Irregular Vagrant) / Belgium: Wallonia / Bosnia and Herzegovina / Bulgaria / Croatia / Czechia / France / France: Mainland / France: Corsica / Germany / Greece / Greece: Mainland / Hungary / Italy / Italy: Mainland / Italy: Sardinia / Liechtenstein / Lithuania / Luxembourg / North Macedonia / Moldova / Montenegro / Netherlands (Irregular Vagrant) / Poland / Romania / European Russia / Serbia / Serbia: Serbia / Serbia: Kosovo / Slovakia / Slovenia / Spain / Spain: Mainland / Switzerland / European Türkiye / Ukraine / United Kingdom / United Kingdom: Great Britain /