Brown Argus - Appearance, Behaviour and Distribution

Appearance, Behaviour and Distribution

Although one of the "Blues" both sexes are brown on the uppersides with a band of orange spots at the border of each wing. They can be mistaken for other female blues but the Brown Argus never has any blue scales at the base of the wings like other female Blues often do. It could also be mistaken for the Northern Brown Argus Aricia artaxrexes were it not for the fact that their ranges do not overlap in the UK, unlike on continental Europe. The underside has the typical "blue" pattern of a greyish/brownish ground colour with black spots outlined in white and a row of orange spots along the border. The pattern of the black spots is the best way to distinguish this species from female Common, Chalk Hill and Adonis Blues as they lack the black spot found near the base of the forewing which is present on these three species. This species has seen an expansion in its range in recent years and is widely distributed across southeast England and most of the Midlands with colonies occurring in Wales and as far north as Yorkshire. These northern sites have seen a lot of confusion in recent years with genetic studies looking at various colonies to separate the two Aricia spp. Until a few years ago, these northern colonies were thought to be the Northern Brown Argus and more colonies may yet be found to be misidentified. Like other blues it is common on the chalk downlands of southern England but will also use other habitats such as woodland clearings, coastal grasslands and heathland. It is widespread across Europe north to southern Sweden and eastwards to Siberia.