Portland Ribbon Wave Idaea degeneraria
Wingspan 26-31 mm.
The stronghold of this moth in Britain is an area in Dorset, on the Isle of Portland. It also occurs occasionally as a migrant along the south coast.
Flying in June and July, sometimes later on the continent, the species is attracted to light.
Little is known of the foodplant in the wild in Britain, but in captivity the larvae will feed on dandelion (Taraxacum) and knotgrass (Polygonum).