Sunday, July 27, 2014

A Dark Variety of Silver-washed Fritillary in Bjerge skov south of Horsens.

Argynnis paphia: Silver-washed Fritillary/ Kejserkåbe; 
dark variety :  Argynnis paphia f. valesina
an orange male meets the valesina

In the month of  July the Silver-washed Fritillary (Argynnis paphia)  is easy to observe in Bjerge/Bjerre skov, a forest south of Horsens. On this day in mid July there were numbers of the pretty orange male flying around among the brambles. The Danish name is Emperor's Robe, and the beautiful deep orange colour with the spots and stripes would fit an emperor very well.
But suddenly came a dark variety, which we had never seen before.There was even a date between an orange male and a dark silver-washed female upon the road. 

This dark variety was named by a famous English lepidopterist Frederick William Frohawk, who named it after his daughter Valezina and called it Argynnis paphia f. valesina.  This spectacular form occurs in a small percentage of females. It is quite distinctive in flight looking like an overgrown ringlet and has the common name of the Greenish Silver-washed Fritillary.

Argynnis paphia f. valesina
Frohawk was the author of Natural History of British Butterflies (1914), The Complete Book of British Butterflies (1934) and Varieties of British Butterflies (1938).  At seven he spotted and caught a rare Pale Clouded Yellow butterfly.  In ab. 1880 Frohawk concentrated on illustration and obtained his first commission for illustrating The Field. Frohawk was encouraged in his work by Lord Walter Rotschild, who later bought his water-colours of butterflies His butterfly collections are now part of the Rothschild collection in the Natural History Museum at London.

Argynnis paphia f. valesina

Silver-washed Fritillary/Kejserkåbe

The Silver-washed fritillary /Kejserkåbe in Denmark:
The spread of the Silver-washed fritillary is somewhat dispersed in Denmark. It has disappeared from large parts of Jutland and Funen. It was earlier widespread in hardwoods in all parts of Denmark.

Problems: The silver-washed fritillary is found in forest glades - and such glades should not be either drained, fertilized or sprayed with pesticides - but hay harvesting and extensive grazing during period would be beneficial. Livestock in the forest is also beneficial,since it brings light and warmth and improved conditions for the violet, which is the host plant of the Silver-washed fritillary.

In the last time of their flight period the Silver-washed fritillary flies often to other habitats, sometimes to residential areas.

The Silver-washed fritillary (Argynnis paphia)  is on the Danish red list, but it is neither protected or listed in Denmark.

Source: Fugle og Natur, Michael Stoltze; British wikipedia, 
photo: Bjerge/Bjerre skov July 2014: grethe bachmann     

1 comment:

Teresa Evangeline said...

What amazing and beautiful things these butterflies are ...