ADULT: Wingspan 35-50mm.  A very distinctive species with a blue-black forewings marked with a prominent white stigmata giving the species its common name.  The hindwings are grey with a dark band. CHRYSALIS: Found throughout winter in a woven cocoon underground. LARVA: Variable in colour such as green and brown with lighter diagonal markings and a hump at the rear.  There also is a thin, white dorsal line.  Feeds on a wide array of plants such as Birch, Alder, Bracken, Willow, Nasturtium and Nettle.  The larva can be conspicuous and sit out in the open through the day. BEHAVIOUR: Attracted to light, sugar and flowers. HABITAT: Deciduous woodland where foodplant grows and also wasteland, parks and gardens. FLIGHT PERIOD: Single brooded.  July to August.  STATUS: Resident.  Common.