Northern Ireland's Priority Species

Tholera cespitis – hedge rustic

 
Tholera cespitis
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Tholera cespitis (Denis & Schiff., 1775)
Family: Noctuidae

A medium sized fairly nondescript dark brown moth of rough grasslands. The main distinguishing features relate to the pale outlined markings on the forewings. It flies in August through September. In the UK the species has undergone a staggering 92% decline in the last 25 years. In Northern Ireland it is most frequently recorded in Counties Down, Tyrone and Fermanagh but is only found regularly at two or three localities.

In brief

  • Historical decline in Northern Ireland. Claims of this species will need supporting evidence such as a photograph
  • It is a Northern Ireland Priority Species because of recorded declines in the UK of 92% over a 25 year period

Species description
A medium-sized member of the Noctuidae, which has a typical resting pose with wings folded over the body. To the uninitiated it looks far from distinctive but the trained eye will quickly notice the clear pale outlines to various markings on the forewing which actually make this moth readily identifiable!

Life cycle
In inhabitant of rough grasslands. The caterpillar feeds at night from March to July on a variety of tough grasses such as mat-grass. The adult is on the wing during August and September. It over-winters as an egg.

Similar species
None. Be aware that many species of moth look very different if they have become worn or abraded

How to see this species
Currently the most reliable place to see this species in Northern Ireland is at Murlough NNR, County Down where it can be trapped sparingly at light. Permission is required to run light traps at this site but some mothing events are run by the staff from time to time. Singletons have been trapped at a wide variety of locations across Northern Ireland but as yet not north of Lough Neagh.

Current status
Scarce, localised and probably declining in Northern Ireland. Declines in the UK are estimated to be 92% over the last 25 years.

Why is this species a priority in Northern Ireland?

  • It is on the Northern Ireland Priority list because of the UK declines which are 92% 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 but the loss of marginal grasslands to intensification and abandonment is likely to be significant.

Conservation of this species

Current action
In Northern Ireland there are no specific actions proposed for this species. The moth has been recorded from some designated ASSIs and Murlough NNR.

Proposed objectives/actions

  • Encourage submission of records, with photographs to aid validation, 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

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

Literature
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