| Family | Lycaenidae |
|---|---|
| Subfamily | Polyommatinae |
| Genus | Cupido |
| Species | osiris |
| Authority | (Meigen, 1829) |
| English Name | Osiris 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 | Near Threatened (NT) |
| Habitats Directive | |
| Bern Convention | |
| CITES |
The Osiris Blue lives on sunny, flower-rich grassland and road verges rich in sainfoin (Onobrychis spp.), which it uses for its nectar and as foodplant. The caterpillar feeds on various sainfoins (Onobrychis spp.), such as Sainfoin (O. viciifolia), Mountain Sainfoin (O. montana), and O. arenaria. In the literature, other leguminous plants are mentioned, e.g. Bladder Senna (Colutea arborescens), Kidney- vetch (Anthyllis vulneraria), and Bitter Vetch (Lathyrus montanus). The eggs are laid on the flowerheads. The caterpillars feed on both the flowers and developing seeds and are attended by ants (e.g. Lasius alienus). The Osiris Blue has one or two broods a year, but the second may only be partial. The caterpillars hibernate and pupate between leaves.
Albania / Austria / Bosnia and Herzegovina / Bulgaria / Croatia / France / France: Mainland / Germany (Regionally Extinct) / Greece / Greece: Mainland / Greece: East Aegean Islands / Hungary / Italy / Italy: Mainland / North Macedonia / Moldova / Montenegro / Romania / European Russia / Serbia / Serbia: Serbia / Serbia: Kosovo / Slovakia / Slovenia / Spain / Spain: Mainland / Switzerland / European Türkiye / Ukraine /