145765 Brown Hairstreak Thecla betulae Wingspan 40-50mm. A lethargic butterfly and a sluggish flier; often prefers to walk over foliage rather than fly. Adult has dark brown upperwings; male has orange patch on forewing. Underwings are orange-brown with white line. Flies August. Larva is slug-like and feeds on Blackthorn. Very local in southern and central England and Wales. Favours Blackthorn scrub and hedgerows.