Geometridae

70.050 Balsam Carpet Xanthorhoe biriviata (Borkhausen, 1794)

Uncommon / probable Immigrant

Similar species: Dark-barred Twin-spot Carpet Xanthorhoe ferrugata and the larger (14 to 16mm) Large Twin-spot Carpet Xanthorhoe quadrifasciata are only likely to be mistaken for this species if it is a dark specimen from the summer brood or it is worn, as they lack the blue-grey markings in the forewing band.

Forewing: 12 to 14mm

Habitats: Wooded stream sides and other water margins, wooded water-meadows and damp woodland.

Habits: The moth flies in the late afternoon and evening sunshine. It flies from dusk and comes to light.

Foodplant: The larva feeds on Orange Balsam and sometimes Small Balsam (both introduced plants). In captivity it will take Touch-me-not Balsam as it does in the wild on the European mainland. There may be another foodplant, as it has been recorded where these plants are not present.