Aricia agestis Denis & Schiffermüller, 1775 ♂
Common names: Brown argus [En], Collier de corail, Argus brun [Fr], Bruin Blauwtje [Nl], Morena serrana [Es], Dunkelbrauner Bläuling [De], Καστανόςάργος [Gr], Çokgözlü Esmer [Tu]
Mount Olympus, PIERIA ● Greece
Description: Unlike most other "blues", the Brown Argus has no blue scales on its upperside, being primarily brown in colour as its name suggests, although it does exhibit a blue sheen when at certain angles to the light. Both sexes have beautiful orange markings on the upperside of both forewings and hindwings.
This species occurs in small, compact colonies, and is not a great wanderer, only travelling a couple of hundred metres, at most, from where it emerged.
Like its close relative, the Common Blue, this species will roost communally on grass stems at night. In fact, the two species are sometimes found roosting together.
The Brown Argus and female Common Blue can be differentiated from their undersides, since the Brown Argus lacks a spot on the underside of the forewing that is present in the Common Blue.
The Brown Argus is also completely lacking in blue scales, but may have a blue sheen. The highly-variable female Common Blue, on the other hand, always has some blue scaling, especially close to the body.
Habitat: The butterfly's traditional habitats are chalk and limestone grassland, but it also occurs in a range of other habitats with disturbed soils, including: coastal grassland and dunes, woodland clearings, heathland, disused railway lines, road verges, and more recently set-aside fields. Sheltered sites or slopes facing south or west are preferred.
Distribution: It is widespread and common across Europe as far north as Denmark and southern Sweden, across to the Middle East and Siberia, and also in North Africa. It has declined in a few western European countries, including in Belgium where it is a rare species [VU].