Local in woodland, parks, hedgerows, scrubby downland and gardens throughout England and Wales, a species of conservation concern under the UK Biodiversity Action Plan. Widely distributed, but perhaps decreasing, in Hampshire and the Isle of Wight. Wingspan 42-50 mm. Probably easier to confuse with Dusky Thorn E. fuscantaria
than September Thorn E. erosaria
, which see, since a good proportion of August Thorn show dark shading between outer cross-line and outer edge of wing, the stated diagnostic feature for Dusky Thorn; the three species all show subtle differences in the way the outer cross-line meets the costa. Larva feeds on Pedunculate and Sessile Oak, over-wintering as an egg.