Common in coniferous woodland, plantations, parks and gardens throughout much of England and Wales. First recorded nationally on the Isle of Wight in 1951, rapidly spreading northwards: in Sussex, first two in 1954, common by 1957; in Dorset, 1959 and soon plentiful; in Surrey, first in 1960, widespread by 1978; in north Hampshire, one at Whitehill, 1960 and widely in south Hampshire from 1965 onwards; north Wiltshire, 1969. Since then its spread has accelerated, reaching west to Cornwall and South Wales, north through the Midlands to Warwickshire and Leicestershire, east to Kent and Suffolk. In Hampshire and on the Isle of Wight it is now one of the commonest autumn moths, benefiting from the widespread planting of Cypress trees in gardens and parks. Wingspan 40-45 mm. The most likely confusion species is
Grey Shoulder-knot L. ornitopus which is lighter grey, has broader and rounder wings, a furcate basal dash, and terminal fascia composed of black dots (MBGBI Vol 10). Larva feeds on flowers and leaves of Monterey Cypress, Lawson's Cypress and Leyland Cypress, over-wintering as an egg.