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 rivularis Prunus rivularis Prunus rivularis, known variously by the common names creek plum, hog plum, or wild-goose plum is a thicket forming shrub. It prefers calcareous clay soil or limestone-based woodland soils. This deciduous plant belongs to the rose family, Rosaceae, and is found mainly in the central United States. It is a shrub consisting of slender stems with umbel clusters of white blossoms. The fruit is a drupe that resembles a large berry; though it has a bitter taste, it serves as a source of food for birds and other wildlife. ""Prunus"" is Latin for plum, whereas ""rivularis"" means being