Brown Hairstreak (Thecla betulae)
Species

Male. Taken at Otmoor, Oxon on August 12th 2011.
(1/125th sec at f11. Approx 2.75x lifesize. © David Hastings)

Male underside. Taken at Otmoor, Oxon on August 2nd 2015.
(1/400th sec at f14. Approx 2.75x lifesize. © David Hastings)

Female. Taken at Otmoor, Oxon on August 15th 2010.
(1/125th sec at f13. Approx 2.75x lifesize. © David Hastings)

Female underside. Taken at Otmoor, Oxon on August 12th 2011.
(1/160th sec at f8. Approx 2.75x lifesize. . © David Hastings)

Description

Wing span: 37 - 44 mm

This is the largest hairstreak found in the British Isles. It is a local species that lives in self-contained colonies that breed in the same area year after year. This species can prove elusive, since adults spend much of their time resting and basking high up in tall shrubs and trees.

This species is found in the southern half of England and Wales, and also in the Burren in Ireland. It is widespread but sporadic through most of Europe (excluding Iberia and S Italy).

It favours areas with extensive networks of hedges and woodland, often on heavy clay soils on low-lying land.

There is one generation each year. This is one of the latest species to emerge in Britain, with adults being on the wing from late July to early September. The ovum is the over-wintering stage.

The primary larval foodplant is Blackthorn; Bullace is also used.

Adults feed primarily on aphid honeydew.

Adults, particularly the males, spend much of the time up in Ash and Oak trees. They will occasionally descend to lower levels to take nectar from flowers.

This species has Vulnerable status on the UK list.

Sightings

20-Aug-2018 : Otmoor, Oxon (1m,1f)
06-Aug-2018 : Otmoor, Oxon (4m,1f)
31-Jul-2018 : Whitecross Green Wood, Oxon (1m)
31-Jul-2018 : Otmoor, Oxon (1m)

16-Aug-2017 : Whitecross Green Wood, Oxon (1f)
15-Aug-2017 : Whitecross Green Wood, Oxon (1f)
03-Aug-2017 : Otmoor, Oxon (1m)

14-Aug-2016 : Whitecross Green Wood, Oxon (2m,1f)

02-Aug-2015 : Otmoor, Oxon (3m)

03-Aug-2014 : Otmoor, Oxon (3m)