As I was having a cup of tea with my father he noted that a nearby Holly bush had come into flower. Moments later a butterfly came nectaring on the flowers- appropriately it is a Holly Blue [worth clicking on the photos to enlarge for a better view].
 Perhaps it should be called a Holly and Ivy Blue because both plants are important in the life cycle of this butterfly. Each year there are two generations. The first generation appears in spring and Holly is both the larval food plant and source of nectar for the butterfly on the wing. The second generation appears in late summer/early autumn and Ivy serves the same purpose.