Northern Ireland's Priority Species

Celaena haworthii – haworth

Celaena haworthii

Celaena haworthii (Curtis, 1829)
Family: Noctuidae

This is a small, relatively common, well-marked, attractive moth of bogs and heaths. It freely comes to light but can be active on warm sunny days when it can be caught whilst nectaring on flowers. It flies in August and September. Caterpillars feed on cotton-grasses and various species of rush. It has declined in the UK by 80% over a 25 year period. In Northern Ireland there is no evidence of such a decline.

In brief

  • Widespread and common on bogs and heaths throughout Northern Ireland
  • The adult flies in August and September
  • Most likely to be encountered at light or whilst nectaring at flowers on warm, sunny days
  • A Northern Ireland Priority Species because of declines detected in other parts of the UK where it has undergone an 80% decline over a 25 year period

Species description
This diminutive moth is extremely well patterned with an obvious white kidney shaped mark which has two white veins (appearing as streaks) extending from it to the outer edge of the wing. The background colour of the forewing is usually a dark purplish brown.

Life cycle
The adult flies in August and September when eggs are laid on the chosen food-plant. It overwinters as an egg. The caterpillar burrows into the stem of cotton-grass or various rushes, changing stems when it out-grows them. Pupation takes place in a cocoon close to the ground.

Similar species

How to see this species
This species is attracted to light and can be taken relatively easily on bogs and heaths. Walking these habitats on warm sunny days checking flowers for nectaring moths can also be productive if you are quick with a net!

Current status
It is widespread and fairly common in suitable habitat throughout Northern Ireland.

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 (80% 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.

Proposed objectives/actions

  • Occurs on a number of designated sites
  • 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, 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

The Butterflies and Moths of Northern Ireland

MothsIreland Website

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

Background information on the Rothamstead Trap Surveys

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

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