| Family | Lycaenidae |
|---|---|
| Subfamily | Polyommatinae |
| Genus | Cyaniris |
| Species | semiargus |
| Authority | (Rottemburg, 1775) |
| English Name | Mazarine 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 Mazarine Blue usually occurs on quite damp vegetation in flower-rich meadows and pastures and at the edges of woodland. These butterflies are fond of basking together in groups and are then easy to find and to be observed. The female deposits her eggs on the flowerheads of Red Clover (Trifolium pratense), eating the unopened buds. The first instar caterpillar only feeds on buds and flowers, later stages also feed on leaves. The colours of the caterpillars are well adapted to their surroundings, with pink in the first instar and then green in later stages. The caterpillars can hardly be seen while feeding on the foodplants. Ants of the genera Lasius and Camponotus attend the caterpillars. Depending on the altitude and position in the range, the Mazarine Blue has one to three generations a year. The hibernation takes place as a larva.
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