|Naturplan foto: stig bachmann nielsen|
Cranberry Fritillary has a wing span of 32-42 mm. It is recognized by the multicoloured underside of the back wing and on the tip of the back wing, which creates a sharp angle. The upperside reminds of the upperside of other fritillaries, but the front wings are pointed and narrow, and the black spots in the middle field make usually a distinct coherent curved line.
The size varies much, and some populations mostly have small individuals. The spread of the dark marking of the upperside vary and the details of the underside vary considerable as to markings and colours.
It flies middle June till late July. Its habitat is bogs with cranberry. It overwinters as a tiny caterpillar in low bog-vegetation, mostly upon the underside of a cranberry leaf. The fodderplanmt of the caterpillar is cranberry.
Cranberry Fritillary lives in Scandinavia, Poland, Czeck Republic, Slovakia, Austria, Germany, Switzerland and in a few localitites in France.
In Denmark has the Cranberry Fritillary has disappeared in many places because raised bogs have been destroyed. At Fyn (Funen) and Sjælland (Zealand) are only left 3 or 4 localitites. The species have disappeared in many places in the eastern part of Jutland, but lives well in other places.
A natural high water level has to be maintained in the rest of the raised bogs, so they do not overgrow - and the bogs must not be exposed to grazing or manuring. Many localities are marked by drainage trenches, which should be filled up - or else grow the bogs into forest, because the peat is exposed to air.
Source: Michael Stoltze, Dagsommerfugle i Danmark, 1998
Cranberry Fritillary, bog north of Madum sø, Himmerland, July 2011:
stig bachmann nielsen Naturplan foto: & grethe bachmann