Tuesday, August 13, 2019

Silver-washed Fritillary/ Kejserkaabe

Argynnis paphia

Silver-washed Fritillary
Bjerre Skov, Horsens, Jutland

The Silver-washed Fritillary is active right now in July until late August, and each year I go to Bjerre forest by Vejle fjord to look for it. It flies in glades and sunny spots of the wood and loves the blackberry flowers. The Danish name Kejserkåbe means Emperor's Cape and this fine coloured pattern would certainly be a beautiful cape for an emperor. The Silver-washed fritillary lives in Europe except southern Spain, Scotland and the northern part of Scandinavia.

The Silver-washed fritillary butterfly is deep orange with black spots on the upper side of its wings and has a wingspan of 54–70 mm, with the male being smaller and paler than the female. The underside is green and unlike other fritillaries has silver streaks instead of silver spots, hence the name silver-washed. A rare variation in some years is a special female, which is green-black with a straw coloured base.

Unusually for a butterfly, the female does not lay her eggs on the leaves or stem of the caterpillar's food source (in this case violets) but instead one or two meters above the woodland floor in the crevices of tree bark close to clumps of violets. The larvae's fodder plants are various Violas.

The Silver-washed Fritillary is a strong flier and more mobile than other fritillaries and as such can be seen gliding above the tree canopy at high speed. Its flight is safe, fast and sailing and it seeks especially to flowers of blackberry and thistles. The mating dance, which can be watched on good localities in the morning, is very characteristic and beautiful. The male flies down under and then steep up in front of the female, who continues to fly straight on, while the male lose speed and once again dives down under and steep up in front of the female.

In Denmark Argynnis pahia is still common at Lolland-Falster, Møns Klint, Sydsjælland and Bornholm, but has during the 1970s and 1980s declined much in Jutland, at Funen, West- and North Sjælland.

Protection of the species:
This species needs many small and unfertilized glades. It thrives well in forests with extensive utilization, like in stævningsskove, (coppicing) which hold many glades in various growth. The Silver-washed Fritillary (Argynnis paphia) is on the Danish Red List as moderately endangered.



In the old days the Silver-washed Fritillary was especially connected to the stævningsskove (Coppicing woods). It is in a serious decline in Denmark, possibly caused by the lack of light-open varied forests. Until ab. 1990 it was numerous in North Jutland in Rold Skov and in Lille Vildmose, but after 1990 it is only known in a few examples, i.e. Rebild, and outside North Jutland in the forests by Vejle fjord, in Gudbjerg skov at Funen and Gribskov in North Sjælland. Still numerous populations in the rest of Sjælland, on the southern islands and Bornholm.

photo Bjerre Skov  grethe bachmann

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