| Family | Lycaenidae |
|---|---|
| Subfamily | Polyommatinae |
| Genus | Aricia |
| Species | agestis |
| Authority | ([Denis & Schiffermüller], 1775) |
| English Name | Brown Argus |
| 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 Brown Argus occurs on warm grasslands, in heaths, and in dunes. It can also be found on sandy, pioneer vegetation, as for example in sand-pits, or where houses are being built. It lays its eggs on small crane’s-bill (Geranium spp.) and rockroses (Helianthemum spp.). It may build up numerous, small populations. At first, the small caterpillars only scrape off the undermost layer of the leaves making little “windows” in the leaves. Later, the bigger caterpillars feed on the whole leaf. They are often attended by Lasius and Myrmica ants. The caterpillars can hibernate at any stage. Pupation takes place in the litter layer. The Brown Argus has two to three generations depending on the geographical location.
Albania / Andorra / Austria / Belarus / Belgium / Belgium: Flanders / Belgium: Wallonia / Bosnia and Herzegovina / Bulgaria / Croatia / Cyprus / Czechia / Denmark / France / France: Mainland / France: Corsica / Germany / Greece / Greece: Mainland / Greece: East Aegean Islands / Greece: Kirti (Crete) / Hungary / Italy / Italy: Mainland / Italy: Sicily / Lithuania / Luxembourg / North Macedonia / Malta (Possibly Present) / Moldova / Montenegro / Netherlands / Poland / Romania / European Russia / San Marino / Serbia / Serbia: Serbia / Serbia: Kosovo / Slovakia / Slovenia / Spain / Spain: Mainland / Sweden / Switzerland / European Türkiye / Ukraine / United Kingdom / United Kingdom: Great Britain / United Kingdom: Guernsey / United Kingdom: Jersey /