Northern Ireland's Priority Species

Pelurga comitata – dark spinach

 
Pelurga comitata
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Pelurga comitata (Linnaeus, 1758)
Family: Geometridae

A rarely recorded moth that appears to be in decline. It was never abundant nor widely distributed but it seems to have disappeared from some of its former haunts. Recent records are mainly coastal in Down and Antrim. The flight period of this small straw coloured moth is from the end of June to mid-August over disturbed ground where its larval foodplants are likely to be more abundant. A Northern Ireland Priority Species because of major declines detected elsewhere in the UK. At present such data does not exist for Northern Ireland.

In brief

  • This is a very scarce moth of rough open spaces and disturbed ground

  • It has one generation on the wing from end of June to mid-August

  • It is attracted to light and flies from dusk

  • It is a Northern Ireland Priority Species because of declines detected in other parts of the UK where it has undergone an 89% decline over a 25 year period. There is evidence that the species has also exhibited a decline in Northern Ireland.

Species description
A member of the Geometridae it can be described as a member of this “butterfly-like” group of moths. It normally rests with the wings open, revealing a straw coloured body and broad rounded wings with a darker, wavy, central cross-band which has a single central projection. At rest the tip of the abdomen is usually raised upward.

Life cycle
The caterpillar is believed to feed on the seeds and flowers of goose-foot and oraches from late-August to October and over-winters underground as a pupa.

Similar species
The Northern Spinach has a similar appearance but the central cross-band on the wings has a double projection Both species curl their abdomens.

How to see this species
Although this moth comes to light there have been very few recent records. Targeting suitable coastal habitat where the food plants are abundant may prove worthwhile. The more recent records of this moth have been from Clandeboye Estate and Murlough NNR (Co. Down).

Current status
Extremely rare but more trapping in the right habitat where the food plants are abundant may produce additional records.

Why is this species a priority in Northern Ireland?

  • Listed as a UK Priority Species and therefore on the Northern Ireland Priority List by default
  • Rapid decline (89% over 25 years 1968-2002) assessed using Rothamstead trap data

Threats/Causes of decline
It is thought to be declining in the UK as a result of many factors, including habitat change, pollution and the use of pesticides.

Conservation of this species

Current action
In Northern Ireland there are no specific actions proposed for this species. General management for Biodiversity such as leaving weedy margins on roadsides, woodland rides and in gardens will help maintain the species.

Proposed objectives/actions

  • Occurs on an NNR
  • Increase Rothamstead Trap network to gather data on status
  • Encourage submission of records to the Moth recorder

What you can do

  • Report all moth sightings to the Moth Recorder for Northern Ireland, Andrew Crory, andrew.crory@gmail.com or use the Butterfly Conservation Northern Ireland (BCNI) sightings web page at http://www.bcni.org.uk/submitsighting.php. 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

Links
The Butterflies and Moths of Northern Ireland

UK Moths Website with an up-to-date distribution map

The state of Britain's moths - an explanation as to how declines have been calculated

Background information on the Rothamstead Trap Surveys

Literature
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. (2009). 3rd revised and updated edition. The colour identification guide to the moths of the British Isles. Apollo Books.
Thompson, R. & Nelson, B. (2006). The Butterflies and Moths of Northern Ireland. NMNI, Belfast.
Waring, P. & Townsend, M. (2009). 2nd edition. Field Guide to the Moths of Great Britain and Ireland. British Wildlife.

Text written by:
Allen & Mellon