Comma,
Polygonia c-album.
A sudden decline meant that in 1920 there were only two sightings in the UK. By 1930 the population recovered and it is now one of the more familiar butterflies. The species survives the winter in the adult stage or can hibernate. Larvae that develop early in the season go on to produce another generation. It gets its name from a comma shaped marking on the underside of its wing.