Purple Hairstreak

This handsome butterfly is widely distributed throughout southern areas wherever there are oak trees; even a solitary tree may support a colony. It is frequently overlooked as adults remain largely in the canopy where the main adult food source is honeydew; they fly more commonly in the evening of a warm summer's day. They are only driven down to seek fluid and nectar during prolonged drought, as occurred in 1995-6. 

There has been a recent increase in records and an extension of the range of this butterfly especially in the English Midlands and south-west Scotland, even in urban areas (including London) which may be related to improvements in atmospheric quality. White-letter Hairstreak is similar but has W-shaped streak. 

Size and Family

• Family: Hairstreaks
• Size: Small
• Wing Span Range (male to female): 37-39mm

Conservation Status

• GB Red List (2022): Least Concern
• Butterfly Conservation priority: Low              
• Fully Protected under the 1985 Northern Ireland Wildlife Order           
• European status: Not threatened 

Caterpillar Foodplants

The Purple Hairstreak is restricted to Oak trees including both the native species, Sessile Oak (Quercus petraea) and Pedunculate Oak (Q. robur), and the introduced Turkey Oak (Q. cerris). Evergreen Oak (Q.ilex) also may be used.

Lifecycle

Habitat

Difficult to spot as it flies around the tops of Oak trees in woods, hedgerows and parks, including in urban areas. 

Distribution

• Countries: England, Wales, Ireland and Scotland
• Widespread in England and Wales, less common in Scotland and Ireland
• Abundance trend: -30% (1976-2019)
• Distribution trend: -57% (1981-2019)