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 serrula typical of "Prunus", are produced in clusters of one to three. The fruit is a small oval bright red drupe. "Prunus serrula" is grown as a ornamental tree, especially for winter interest. It tolerates a variety of soil types and has a wide pH range. It prefers full sun and does well in USDA hardiness zones 5 to 8. Its potential as an invasive species is low, as it is susceptible to many common garden diseases and pests such as fire blight, powdery mildew and Japanese beetles. It is sometimes grafted to "Prunus serrulata" (Japanese cherry) crowns, forming a tree