Sand Pill-millipede (Trachysphaera lobata)
Key Details
| Taxonomic Groups: | Invertebrate > millipede > Millipede |
| Red List Status: | Vulnerable (Not Relevant) [VU(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: | Trachysphaera lobata |
| UKSI Recommended Authority: | (Ribaut, 1954) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Lee, 2015 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | VU, only 2 populations known in England, both very limited in extent, very different in nature and both threatened |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Site protection, specialist survey and genetic studies are all required. The variation between cave sites and the wood are too great and common factors need clarifying. |
| 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: | Far too restricted |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Unknown |
| National Monitoring Resource: | Combination - insufficient |
| Species Comments: | Population at Bembridge is threatened by coastal erosion. Density was estimated from field survey in 1986, 2005 and 2011 and had declined by over 50% over this period. The discovery of a second population in old mines at Prideaux Woods, Cornwall in 2018 was unexpected and requires further research |
Key Actions
Key Action 1
Proposed Action: Targeted survey of cave and old mine systems in SW to estimate size and extent of subterranean populations
Action targets: 2. Biological status assessment exists
Action type: Status survey/review
Duration: 3-5 years
Scale of Implementation: ≤ 10 sites
High priority sites: Start with known location at Prideaux Woods, Cornwall, then expand to cover potential sites adjusting target sites based on results of each previous survey
Comments: Action will require specialist skills of a caver with knowledge of the species. Also will require support from NE to access sites that are also bat roosts. Understanding if it is much more widespread underground will bring clarity about the importance of above ground sites.
Key Action 2
Proposed Action: Collect specimens from subterranean populations for analysis of mitochondrial DNA. Use data to determine origins and relationships of mine/cave populations to each other and to Bembridge population. Assess degree of fragmentation of national population
Action targets: 1. Taxonomy established
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: ≤ 10 sites
High priority sites: Start with known location at Prideaux Woods, Cornwall
Comments: Can be undertaken alongside status survey with extra costs for genetic analysis. Work has already been carried out on IOW population. Important to set in a near European context too to understand if there has been any genetic drift post English channel formation
Key Action 3
Proposed Action: Identify potential sites on IOW as translocation receptors when coastal erosion results in imminent demise of Bembridge population
Action targets: 5. Remedial action identified
Action type: (Re-)introduction
Duration: >10 years
Scale of Implementation: ≤ 5 sites
High priority sites: Start with known location at Prideaux Woods, Cornwall
Comments: Timescale for ultimate loss of Bembridge site is unknown but erosion will need to be monitored if population is to be moved. It might be worth looking on the mainland as well as IoW.
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.