Black hairstreak forewings. The most conclusive way to distinguish the two is by the row of black spots accompanying the orange band which the white-letter hairstreak never has. They spend most of their lives in the canopy or in dense scrub, feeding on honeydew, and very rarely come down to ground level. Eggs are laid singly on young blackthorn "Prunus spinosa" growth and it is this stage which hibernates. Although blackthorn is the main foodplant, wild plum "Prunus domestica" and other "Prunus" spp are occasionally used. The caterpillar hatches the following spring, at the end of April, just before the buds open
Prunus japonica Prunus japonica Prunus japonica (also "Cerasus japonica"), also called Japanese bush cherry, or Oriental bush cherry, or Korean bush cherry is a shrub species in the genus "Prunus" that is widely cultivated for ornamental use. Its native range extends from Central China through to the Korean peninsula. "P. maximowiczii", the Miyama cherry is also often referred to as Japanese bush cherry. The shrub reaches 1.5 m by 1.5 m. Its flowers are hermaphrodite and are pollinated by insects. The plant blossoms in May. Its fruit reaches about 14 mm and has an agreeably sweet flavor, therefore it is used in