Scientific name: Satyrium pruni
The Black Hairstreak butterfly is one of Britain’s most elusive butterfly species. It is found only in the Blackthorn thickets of woodlands on heavy clay soils between Oxford and Peterborough in the East Midlands of England.
The Black Hairstreak spend nearly all their time in the canopies of trees of dense scrub where they feed on honeydew secreted by aphids. They spend very little time in flight, but at certain times they make short looping flights in and out of the tree tops with a peak of activity around midday.
Underwings are brown with red edges, a row of black spots, a white streak, and small tails. Upperwings are brown with red edges.
The adults are easy to confuse with those of the White-letter Hairstreak and Purple Hairstreak which fly at the same time of year, care is needed to confirm identification of the underside marking, which has a row of black spots in the outer orange marking and may have a white ‘W’.
The Black Hairstreak has unfortunately declined steadily during the twentieth century and is now reduced to around 50 sites.