This is a fritillary of hot places where knapweed grows. It is large compared to most Mellicta/Melitaea
species and also rather bright and colourful, meaning that it is really
quite easy to identify. However, not all are as distinctive as the
insects on this page - sometimes, especially further north, they can be
smaller and even have black spots in the postdiscal row on the
hindwing, like a Glanville fritillary. In all forms, the single large,
inwardly displaced submarginal lunule on the forewing is a useful
diagnostic sign.