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 mume a salty, sour condiment. A very similar variety of pickled plum, ' or ' is used in Vietnamese cuisine. The best fruit for this are from the forest around the Hương Pagoda in Hà Tây Province. "Prunus mume" is a common fruit in Asia and used in traditional Chinese medicine. It has long been used as a traditional drug and healthy food in East Asian countries. A recent study has indicated that "Prunus mume" extract is a potential candidate for developing an oral antimicrobial agent to control or prevent dental diseases associated with several oral pathogenic bacteria. Recent studies have