Tim writes: The Northern Brown Argus occurs across northern Europe and the mountains further south but the form that occurs in Scotland occurs nowhere else. This beautiful (and little-photographed) form has a white spot on the forewing and the under side spots are white without black centres. These features are controlled by a single recessive gene, seemingly present in all Scottish butterflies and a small proportion of butterflies on the County Durham coast. Butterflies in northern England usually lack the white spot and have small black centres to the underside spotting.
This individual has unusually marked wings in that it almost completely lacks the row of orange lunules around the margin. This would be known as aberration unicolor. It also has an iridescent bloom across its wings, that is only seen in butterflies soon after they emerge from the pupa. I photographed this one at a site on the coast in County Durham where white spotted individuals are a rare but recurring form.
Taken with a Nikon D5000 and a Nikkor 18-200mm at 200mm f8 1/640 ISO 250
[registration_form]