Large Marsh Grasshopper (Stethophyma grossum)
Key Details
| Taxonomic Groups: | Invertebrate > insect - orthopteran > Grasshopper, cricket or ally |
| Red List Status: | Near Threatened (Not Relevant) [NT(nr)] |
| D5 Status: | Included in the baseline Red List Index for England (Wilkins, Wilson & Brown, 2022) |
| Section 41 Status: | (not listed) |
| Taxa Included Synonym: | (none) |
| UKSI Recommended Name: | Stethophyma grossum |
| UKSI Recommended Authority: | (Linnaeus, 1758) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Sutton, 2015 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | Listed as Near threatened on the GB Red List and all British populations are in southern England. Has shown a steep decline (85% range reduction between 1985 and 2010) due to land drainage and in England is now confined to acid/ quaking bogs/ mires in the New Forest & Dorset, together with recently translocated populations in Norfolk. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Captive rearing and translocations have recently proved to be successful conservation actions for this species. Drainage of the bog habitat has been cited as the cause of the decline of this species, so targeted habitat management may also be required. |
| Question 3: | At a landscape scale, would the species benefit from untargeted habitat management to increase habitat mosaics, structural diversity, or particular successional stages? |
| Response: | No |
| Justification: | This species would not benefit from untargeted management |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 6. Recovery solutions trialled |
| Recovery potential/expectation: | Medium-high |
| National Monitoring Resource: | Structured - insufficient |
| Species Comments: | Captive rearing and translocations have recently proved to be successful conservation actions for this species, with follow up monitoring |
Key Actions
Key Action 1
Proposed Action: Undertake further conservation translocations. Captive rearing and translocation conducted by Citizen Zoo, supported by Natural England, have proved to be successful. This action includes further re-enforcement, where necessary, of the recently (2021) translocated populations (e.g. at Dersingham bog/ Wild Ken Hill in Norfolk), scoping for further potential receptor sites within the former range of the species (Norfolk broads, Cambridgeshire fens, Thames valley, Somerset levels, Surrey heaths) and new conservation translocations to suitable sites.
Action targets: 6. Recovery solutions trialled
Action type: (Re-)introduction
Duration: 6-10 years
Scale of Implementation: ≤ 5 sites
High priority sites: Sites of recent translocations by Citizen zoo- including Dersingham bog and Wild Ken Hill may require further reinforcement.
Comments: Citizen zoo received funding in 2023 from the Natural England Species Recovery Capital grant scheme to reintroduce the species to its former range withing East Anglia
Key Action 2
Proposed Action: Undertake appropriate habitat management of existing and new sites. The past decline of the species was linked with drainage of habitat. With climate change, it is important to ensure that existing and new sites are managed to retain the bog habitat. Sites which have been drained in the past, but which could provide suitable habitat could be re-wetted by, for example, filling in drainage ditches. In addition, open corridors through forestry plantations might aid natural colonisation (as the species can fly). Gardiner and Miller (2022) advise against grazing sites at high density, as this can damage egg pods in the soil, and recommend the provision of un-grazed refuge areas.
Action targets: 6. Recovery solutions trialled
Action type: Habitat management
Duration: >10 years
Scale of Implementation: ≤ 10 sites
High priority sites: New Forest and Dorset heaths together with new sites in Norfolk such as Dersingham bog
Comments:
Acknowledgment:
Data used on this website are adapted from Threatened species recovery actions 2025 baseline (JP065): Technical report and spreadsheet user guide (Natural England, 2025). Available here.