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 pumila leathery, long, with a serrated margin. The flowers are in diameter with five white petals and 25–30 stamens. They are produced in small clusters of two to four. The fruit is a small cherry diameter, ripening dark purple in early summer. "Prunus × cistena" (purple leaf sand cherry) is a hybrid of "Prunus cerasifera" (Cherry Plum) and "Prunus pumila". It was developed by Niels Ebbesen Hansen of South Dakota State University in 1910. Prunus pumila Prunus pumila, commonly called sand cherry, is a North American species of cherry in the rose family. It is widespread in eastern and central Canada