Current status
The large marsh grasshopper is the UK`s largest grasshopper. It is restricted to very wet, marshy areas, commonly quaking acidic bogs, although historically the species also occupied fenland and riverside habitats. The detailed ecology of the species is poorly known. It appears that eggs (in batches of 10-14, in elongated pods) are laid at the bases of grass stems. Four nymphal instars are reported, with the first emerging in May/June; the adult stage is attained by mid July and adults may survive into November in favourable conditions.
The UK range of the large marsh grasshopper formerly included the Thames Valley (to the mid 19th century) and East Anglia (to the late 1960s). The species has declined severely in the Somerset Levels since around 1960, and its current status in this area is unclear; the last confirmed records are from 1989 at one site and 1995 at a second. Two small, isolated colonies in Surrey (at least one of which arose from an introduction in the late 1960s) have not been confirmed since 1991. There are currently a number of populations in Dorset and the New Forest, but little information on their size is available other than to suggest that most are small. The species is present throughout Europe (except in the extreme south), extending eastwards into the former Soviet Union, but it is vulnerable to habitat loss throughout its range. UK populations represent some of the most northerly colonies of the species.
In Great Britain this species is classified as Vulnerable.
Current factors causing loss or decline
Drainage of wetlands for land reclamation and peat extraction has had a major impact on the large marsh grasshopper.
Land use on areas adjacent to occupied sites may also affect this species through pollution and impact on local water tables.
Climate change may adversely affect this species, through the drying-out of suitable habitat.
Current action
Clarification of the current range and status of this species in the UK was the subject of a project under the NE Species Recovery Programme in 1997.
Recent surveys by the Dorset Environmental Records Centre have contributed to the assessment of the species` status in this county.
Most known extant populations of the large marsh grasshopper occur in SSSIs and/or NNRs.
Bristol Zoo is currently investigating a captive breeding strategy for this species.
A species action plan, commissioned by NE, was written in 1997.
Action plan objectives and targets
Prevent further contraction in range.
Prevent further decline in population sizes at known sites.
Restore populations to five suitable sites within the historic range of the species by 2010.
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)
Address the requirements of this species in the LEAP process and in relevant WLMPs. (ACTION: EA, IDBs, LAs, MAFF)
Take account of the species? requirements in response to applications for water abstraction licences. (ACTION: EA)
Site safeguard and management
Where possible, ensure that all occupied and potential habitat is appropriately managed by 2010, for example through SSSI or agri-environment scheme management agreements. (ACTION: NE, MAFF)
Ensure that the habitat requirements of the large marsh grasshopper are taken into account in any relevant development policies, plans and proposals. (ACTION: NE, LAs)
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 this species, where this is necessary to secure their long-term protection and appropriate management. (ACTION: NE).
Species management and protection
(Re)introduce the large marsh grasshopper to sites within the former range of the species, where appropriate habitat and site management are available, in order to restore populations to five sites. (ACTION: NE).
Advisory
Advise landowners and managers of the presence of the species and the importance of beneficial management for its conservation. (ACTION: NE)
Future Research and Monitoring
Undertake further surveys to determine the status of this species and to identify potential sites for (re)introductions. (ACTION: NE)
Conduct targeted autecological research to inform habitat management. (ACTION: NE)
Establish a regular monitoring programme for this species. (ACTION: NE)
Support the development of a captive breeding strategy as a component of any (re)introduction programme. (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 by a publicity leaflet. (ACTION: NE).
Links with other action plans
None given.
Local implementation
The following LBAPs are working on Stethophyma grossum:
Publication details
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume IV: Invertebrates (March 1999, Tranche 2, Vol IV, p453)
Related links
ARKive Visit the ARKive website to view images and further information relating to this species