Silver-washed Fritillary On A Scottish Thistle

This butterfly is our largest fritillary and gets its name from the beautiful streaks of silver found on the underside of the wings. The bright orange male is quite distinctive as it flies powerfully along woodland rides, pausing only briefly to feed or investigate anything with an orange hue that could be a potential mate. The male has four distinctive black veins on its forewings that contain special “androconial” scales that are used in courtship. These veins are known as “sex brands”. The female is paler than the male, has rounder wings and more-prominent spots. In England and Wales, the Silver-washed Fritillary is found in woodlands south of a line between Montgomeryshire in the west and East Kent in the east, with a few scattered colonies elsewhere, including those in Westmorland and West Lancashire. This species is also widely distributed in Ireland, but is absent from Scotland, the Isle of Man and the Channel Islands.
The picture was taken in the Yorkshire Dales below the Middlesmoor Pasture trig point in grid square SD 96 71.