White-letter Hairstreak (Satyrium w-album)
Named for the shape of a letter W formed by the white line on the hind wing, this species is another tree-top dweller, dependant on elms and consequently much rarer than formerly, though well worth seeking where elms survive.
The adults feed on aphid honeydew in the trees but sometimes come to nectar on brambles and thistles. Both sexes are a drab brown above
Flight Period: June - August