Clubbed General (Stratiomys chamaeleon)
Key Details
| Taxonomic Groups: | Invertebrate > insect - true fly (Diptera) > Soldier fly or ally |
| Red List Status: | Endangered (Not Relevant) [EN(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: | Stratiomys chamaeleon |
| UKSI Recommended Authority: | (Linnaeus, 1758) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Drake, 2017 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | From being widespread in the past, the species is now confined to areas in England; Cothill Fen & Parsonage Moor SSSI and the nearby Dry Sandford Pit |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | The habitat requirements for the larvae to develop are specific and rare even within the sites the fly inhabits, the risk of habitat loss through scrub and reed encroachment is high and the work needed to maintain this is intensive and in some cases requiring specialist (botany) guidance to protect other endangered orders. |
| 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: | Taking succession back to the earliest favourable stages within the fen, i.e. bare wet moss mats and open warm runnels will potentially allow further spread of the population. Rewetting and management of local fens that are not populated at the moment may allow further spread. Species needs targeted action for this and is not really at landscape scale |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 5. Remedial action identified |
| Recovery potential/expectation: | Medium-high |
| National Monitoring Resource: | Structured - sufficient |
| Species Comments: | A rare fly that is being monitored and work on habitats has been implemented but this does to a large extent rely on volunteers as well as the Freshwater Habitats Trust (At Cothill and Parsonage Moor). The larval habitat niche is specific and rare even in the populated sites. The larval reliance on tufa rich seepages, unicellular algae, protozoa and finely divided detritus with stonewort and wet moss mats to hide in, means that they are at extreme risk from drying of the sites and shading/encroachment of fen vegetation. |
Key Actions
Key Action 1
Proposed Action: Removal of reed and sedge that are filling shallow pools and runnels on site
Action targets: 6. Recovery solutions trialled
Action type: Habitat management
Duration: >10 years
Scale of Implementation: 1 site
High priority sites: Dry Sandford Pit SSSI (SU467996)
Comments: The necessary work has been assessed by the Wildlife Trust as too hard for volunteers. Removal with care is sensible. Marking orchid positions with high viz markers beforehand would seem sensible, especially as the work is likely to be out of flowering time. On site guidance by specialist botanist is required at this site to supervise Reed/Sedge clearance, due to presence of protected Orchids within some areas of the site.
Key Action 2
Proposed Action: Liaising with land managers for specific site requirements, a professional ecologist (entomologist/botanist; Judy Webb) is heavily involved with conservations measures on these sites and has a huge amount of knowledge relevant to the sites.
Action targets: 7. Best approach adopted at appropriate scales
Action type: Special (in situ) measure
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites: Cothill Fen SSSI, Berkshire (SU460998) & Dry Sandford Pit (SU468995)
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.