Description: Wingspan 24-30mm. Adults have brownish forewings with a distinctive white band. There is a single indention on the inner margin of the band. Beginning of June to early August.

World Distribution: Northern and Central Europe.

Irish Distribution: Widely distributed but local, with most of the recent records from Down. Recorded recently on the North Antrim coast at Portrush, which is the only recent record north of Lough Neagh, although old records exist for Magilligan and Banagher Glen, Londonderry. It has also been taken at Aghalee, Antrim, and the Lagan Meadows and Belfast, Down in the late 1990s.

Ecology: A woodland species that is much less frequently encountered than the closely related Small Rivulet P. alchemillata. The lack of records in the west is probably due to the scarcity of its foodplant. Adults are attracted to light in very small numbers. The larvae can be found from July to September in the seed capsules of Red Campion Silene dioica. It overwinters as a pupa.

Key Identification Features:

• White band with single indentation on inner margin
• Pale whitish-brown hindwings with brownish band at outer margin

Distribution Map from NBN: Perizoma affinitata at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Perizoma affinitata at iNaturalist World Species Observations database.