Melanargia galathea, the marbled white, is a butterfly in the family Nymphalidae. Found across most of Europe, southern Russia, Asia Minor and Iran. It is not found in Ireland, North Britain, Scandinavia (except Denmark) and Portugal or Spain. Despite its common name and appearance, this butterfly is one of the “browns”, of the subfamily Satyrinae.

Like other members of its subfamily, the larvae feed on various grasses. Eggs are laid on the wing, or from brief perches on grass stems, and are just sprinkled among the grass stems. Upon hatching, the larvae immediately enter hibernation and only feed the following spring when the fresh growth occurs. Adults emerge in July, and, on a good site, in warm, sunny weather, thousands can be seen gently fluttering amongst the grass heads.

Source: Wikipedia