The Purple Hairstreak is the commonest of the hairstreak butterflies recorded in Britain; however, because they spend most of the time high up in the canopy of oak woodland it is not easy to get to see these lovely butterflies,
Pictured above is a female, which has two purple patches on the forewing only. Males have a glossy purple sheen on the upperside of both their forewings and their hindwings. The underside is light grey with a white streak, edged in black, running down both wings. There are two short tails on the hindwings, with two orange spots at the base on the underside.
Purple Hairstreak butterflies inhabit oak woodlands, particularly in southern Britain but also locally further north. (The specific epithet quercus means 'oak'.) Because of their habit of flitting back and forth high up in the canopy, the Purple Hairstreak is rarely seen clearly except during one of its occasional excursions to low bushes or scrub on a woodland edge, ride or clearing.
In Britain the Purple Hairstreak is most commonly found in southern England and South Wales, but it does occur, although less frequently, in southern and central mainland Scotland. In Ireland this species is also most common in southern counties..
Elsewhere, on mainland Europe, Purple Hairstreaks are recorded from most countries from Scandinavia down to the Mediterranean; this species is also found in parts of north Africa.
In summer the eggs, looking rather like miniature Sea Urchins, are usually laid singly on the bases of Oak buds. Oaks arethe foodplants used by larvae (caterpillars) of the Purple Hairstreak. The caterpillars develop very quickly within the eggs but then remain there in a dormant state, overwintering until the following spring.
In the spring, stout brown pupae, typically 1cm long, form either just below the soil surface or beneath leaf litter, moss or tree bark. After about four weeks as pupae, a single brood of adults emerge from late June through into August.
This page includes pictures kindly contributed by Rob Petley-Jones and by the Countryside Council for Wales (CCW).
If you found this information helpful, you would probably find the new 2017 edition of our bestselling book Matching the Hatch by Pat O'Reilly very useful. Get an author-signed copy here...