Black Hairstreak (Satyrium pruni)

Family: Lycaenidae Checklist: 61.007

 
Description
Wing span: 34-40 mm. The Black Hairstreak is one the rarest British butterflies and one of the most recently discovered, due to its similarity to the White-letter Hairstreak. The main distinguishing feature between the two is that the Black Hairstreak has a row of distinctive black dots running along the inside of the orange band on the underside of the hindwing; these are absent in the White-letter Hairstreak. Males and females are similar, but the hindwing tails are longer in females. They always rest with their wings closed. This species has a very restricted distribution that follows a line of clay soils between Peterborough and Oxford. Black Hairstreak colonies are typically located in small woods or nearby hedgerows, where stands of mature Blackthorn grow. Sites are located in sheltered but sunny positions and have a southerly aspect to them.
 
Images (click to enlarge)
Black Hairstreak ♂ underside © David Hastings
Black Hairstreak ♀ underside © David Hastings
Male underside Female underside
 
Life Cycle
The Black Hairstreak has a short flight period, with the adults normally being seen from early June to the first week of July. The ovum is the over-wintering stage.
 
Larval Foodplants
The primary larval food plant is Blackthorn (Prunus spinosa).
 
Nectar Sources
As well as aphid honeydew, adults will also take nectar from flowers such as Wild Privet, Dog Rose and Bramble.
 
UK Conservation Status
Endangered
 
Earliest UTB first sighting (since 2004) : 24th May
Mean UTB first sighting (since 2004) : 6th June
 
Species Champion
Stuart Hodges
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Reports
 
Distribution and Sites
 

Key
1 sighting 2-9 max seen 10+ max seen
This species is a habitat specialist. It can be found at these sites:
Buckinghamshire
Bernwood Forest
Bernwood Meadows
Calvert Jubilee
Chinkwell Wood
Finemere Wood
Howe Park Wood
Rushbeds Wood/Lapland Farm Meadows
Oxfordshire
Asham Meads
Otmoor
Piddington Wood
Shotover Country Park
Waterperry Wood
Whitecross Green Wood
Wytham Woods

 
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