Current status
The basil thyme case-bearer has been recorded in Britain only from unimproved grassland, including road verges, grazed solely by rabbits. The larvae feed on basil thyme Acinos arvensis seedheads in open conditions in early autumn before moving onto grasses on which they overwinter and feed in spring. Adults are on the wing in July and early August. Although there is no direct evidence that this species is in decline, basil thyme has declined in the Brecks and surrounding area. This is thought to be due to a reduction in grazing levels and ground disturbance, particularly that produced by rabbits.
This species has been recorded only from the Breckland district of Suffolk and Norfolk. Larvae have been recorded at two sites and adults at another. In 1996 the species was recorded in good numbers on a road verge in Suffolk. At one of the sites in Norfolk, owned by the MoD, the moth has not been recorded since the mid 1970s and the habitat there now appears to be unsuitable. Elsewhere in Europe, this species has been recorded at only a single site in Switzerland.
In Great Britain this species is classified as Endangered.
Current factors causing loss or decline
Decline in the abundance of the foodplant due to reductions in grazing intensity, particularly as a result of changes in rabbit populations.
Loss of unimproved Breck grassland.
Current action
A small number of Breckland sites were surveyed for the species by the Norfolk Moth Survey in 1997.
Action plan objectives and targets
Maintain populations at all known sites.
Enhance the population size at all known sites by 2010.
Ensure that 10 viable populations occur within the current range by 2010, using introductions if necessary.
Proposed actions with lead agencies
Policy and legislation
Where appropriate, include the requirements of the species when preparing or revising prescriptions for agri-environment schemes. (ACTION: NE, MAFF)
Site safeguard and management
Where possible, ensure that all occupied and nearby potential habitat is appropriately managed by 2008. (ACTION: NE, FE, MAFF, MoD)
Ensure that the species is included in site management documents for all relevant SSSIs. (ACTION: NE)
Consider notifying as SSSIs sites holding key populations of the species, where necessary to secure their long-term protection and appropriate management. (ACTION: NE)
Species management and protection
Introduce the basil thyme case-bearer to a series of sites within the known range, if necessary to achieve 10 viable populations by 2010. (ACTION: NE)
Advisory
Advise landowners and managers of the presence of the species and the importance of beneficial management for its conservation. (ACTION: NE, MAFF)
As far as possible, ensure that all relevant agri-environment project officers, and members of regional agri-environment consultation groups, are advised of locations of this species, its importance, and the management needed for its conservation. (ACTION: NE, MAFF)
Future Research and Monitoring
Undertake surveys to determine the status of this species. (ACTION: NE)
Conduct targeted autecological research to inform habitat management. (ACTION: NE)
Establish a regular monitoring programme for the species. (ACTION: NE)
Pass information gathered during survey and monitoring of this species to a central database for incorporation into national and international databases. (ACTION: NE)
Communications and Publicity
Promote opportunities for the appreciation of the species and the conservation issues associated with its habitat. This should be achieved through articles within appropriate journals, as well as a publicity leaflet. (ACTION: NE)
Links with other action plans
None given.
Publication details
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume IV: Invertebrates (March 1999, Tranche 2, Vol IV, p315)
Related links
ARKive Visit the ARKive website to view images and further information relating to this species