Black Hairstreak Satyrium pruni

Underside. Sexes appear similar. The row of black dots on hindwing allows species to be distinguished from other hairstreaks.
Underside. Sexes appear similar. The row of black dots on hindwing allows species to be distinguished from other hairstreaks.
This one is taking in moisture from a leaf.
This one is taking in moisture from a leaf.
 
Information

Law: Protection under the Wildlife and Countryside Act 1981.
Red List status: Endangered
NERC Act S41: Not listed
Local status: Rare. (Bedfordshire's rarest butterfly).
Only found in a couple of small colonies, some on private property.
Only about 45 colonies exist in the whole of Britain, all in south-east midlands.
Size: Small.
Larval foodplant: Blackthorn.
No. of broods: One.
Flight time(s): Only about 3 weeks duration(!) usually during second half of June, but flight period varies each year, so to avoid missing it completely start looking before mid-June.
Average first date: 13th June
Average last date: 24th June
Winter: Egg.
Habits: Never settles with wings open. Occasionally flies, but loves to skulk around the tops of trees out of sight, feeding on honeydew. May come down to feed on wild privet or bramble. Often requires lots of patience to find and binoculars to get a good view. Please report if you see one as you may be the only one to do so that year!
Habitats: Mature thickets of sheltered sunny Blackthorn, usually in woodland.
Distribution: