Local on heathland and moorland, and in bogs throughout the British Isles, a species of conservation concern under the UK Biodiversity Action Plan. In Hampshire common on heathland in the New Forest and in the north-east, but uncommon elsewhere and on the Isle of Wight. Wingspan 36-42 mm. Variable, with the grey form
neglecta more common in the south of Britain, and red forms in the north of Britain; in north-east Hampshire both grey and red forms occur. The grey form may be confused with
Square-spot Rustic X. xanthographa, but
X. castanea always characterised by reniform and orbicular stigmata inconspicuous, concolorous with ground colour, outlined ochreous, and reniform stigma with dark dot in dorsal half (MBGBI Vol 9). Larva feeds on Heather, Bell Heather and Cross-leaved Heath.