Northern Ireland's Priority Species

Perizoma blandiata – pretty pinion

Perizoma blandiata
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Perizoma blandiata (Denis & Schiffermuller, 1775)
Family: Geometridae

This small ‘butterfly-like’ moth is closely associated with herb rich grassland, especially on the coast and more unusually in Northern Ireland, upland grassland/moorland. It is closely associated with its larval foodplant, eyebright. In Northern Ireland it is rare and somewhat erratic in its occurrence.

In brief

  • The most recent records are from the Umbra, County Londonderry

  • Its habitat is herb-rich grassland on stable sand dunes and limestone grassland.

  • Best seen, late May to early August

  • It has undergone rapid decline and is very rare

  • Single records from scattered localities suggest it may be more widespread than recent records suggest

  • Threats are unknown, but likely to be linked to agricultural improvement and a loss of herb-rich grassland.

Species description
This small moth is mainly white/pale grey with a faint crossband across the forewing which darkens into a rounded black patch on the leading edge. A pale greyish band runs around the rear edge of the wing. The hind wings are whitish-grey.

Life cycle
The adult is on the wing from the end of May until early August. It can be found flying in the later part of the day during periods of warm sunshine. It is also freely attracted to light. The larvae feed on the flowers and seeds of eyebright species during August and September, overwintering as a pupa.

Similar species
The garden carpet shares a similar forewing pattern but is significantly larger and generally darker. The black patch on the leading edge of the forewing is also larger, angled and indented rather than rounded.

How to see this species
Adults should be looked for on suitable days in June, July and early August. Visits on warm, still, sunny days are likely to be most productive when patches of eyebright should be swept with a butterfly net. Light trapping close to patches of the foodplant can also be productive. Relevant access permissions should always be sought prior to visiting any sites.

Current status
All the most recent records are from the Umbra, County Londonderry (1998 and 2004). Other records within the last twenty years are from Rathlin Island, County Antrim and Lisblake Bog, County Fermanagh. Historically it was recorded from four other scattered sites in Down, Antrim and Tyrone.

Why is this species a priority in Northern Ireland?

  • Very rare – apparently confined to a small population at one site in Northern Ireland

  • The available records suggest that it has seriously declined in range.

Threats/Causes of decline
Unknown but likely to be linked to agricultural improvement and a loss of herb-rich grassland.

Conservation of this species

Current action

  • The Umbra is designated as an ASSI and SAC by EHS and managed by the Ulster Wildlife Trust

  • Implementation of the Northern Ireland Habitat Action Plans for Calcareous Grassland and Coastal Sand Dunes.

Proposed objectives/actions

  • Maintain existing population

  • Check other potential sites for ‘new’ populations

  • Carry out appropriate management on habitats where eyebright is abundant.

What you can do

  • Report all moth sightings to the Moth Recorder for Northern Ireland, Andrew Crory, or use the Butterfly Conservation Northern Ireland (BCNI) sightings web page at The BCNI database is managed by CEDaR and these records will then be used to update the Butterflies and Moths of Northern Ireland website.
  • Join Butterfly Conservation. Butterflies and Moths are in serious decline — with your support Butterfly Conservation can take action to reverse this.

Further information

Butterflies and Moths of Northern Ireland.

A general UK overview.

Northern Ireland Habitat Action Plans

Designated sites – ASSI

Baynes, E.S.A. (1964). A revised catalogue of Irish macrolepidoptera (Butterflies and Moths) . EW Classey, Hampton, Middlesex.

Porter, J. (1997). The colour identification guide to caterpillars of the British Isles. Viking, London.

Skinner, B. (1988). The colour identification guide to the moths of the British Isles. Viking, London.

Waring, P. and Townsend, M. (2003). Field Guide to the Moths of Great Britain and Ireland. British Wildlife Publishing, Hants.

Text written by:
Allen & Mellon Environmental Ltd.