Cyrturella albosetosa
Key Details
| Taxonomic Groups: | Invertebrate > insect - true fly (Diptera) > Long-legged fly |
| Red List Status: | Critically Endangered (Not Relevant) [CR(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: | Cyrturella albosetosa |
| UKSI Recommended Authority: | (Strobl in Czerny & Strobl, 1909) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Drake, 2018 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | Known sites fed by base rich water and are permanently wet. Fen flora especially blunt-flowered rush (Juncus subnodulosus) and black bog rush (Schoenus nigricans); Ducan's Marsh was lightly grazed and the area at Chippenham Fen where the fly occurred, was mowed. The site habitat is rare and being a small site could be lost if not managed correctly. The fly is considered extinct at Chippenham Fen |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Targeted actions at the one remaining site are critical if the fly is to survive in England (assuming no other undiscovered populations). Note that the fly is tiny (≤ 1.2mm) and thus may be missed or dismissed by less experienced entomologists). With no records since 2007 the need for ongoing surveying to establish whether the population at the known site persists is necessary. |
| 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: | The species appears to be habitat specific and altering the landscape in general is unlikely to allow expansion of the range. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 4. Autecology and pressures understood |
| Recovery potential/expectation: | Low - Extinction debt |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | Only known site post 2000 is Ducan's Fen SSSI Norfolk (TG339027) records from 2007. Previous records from Chippenham Fen but presumed extinct in that location; last records 1951. The fly is only 1.2mm long and therefore may have been missed, misidentified or ignored, although it is considered to be rare in Europe. |
Key Actions
Key Action 1
Proposed Action: Tailored surveys of habitat in known locality to determine whether the population still exists or is extinct in this location
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: 2 years
Scale of Implementation: 1 site
High priority sites: Ducan's Fen SSSI Norfolk (TG339027)
Comments: Specialist dipterist/ecological survey, tailored to be as non-invasive as possible as population is isolated and size unknown if it still exists. Short scale inspection would prevent taking out the whole population.
Key Action 2
Proposed Action: Working in conjunction with the land manager to ensure management of fragile mire areas is critical. This includes reducing scrub encroachment, suitable light grazing and water level management.
Action targets: 4. Autecology and pressures understood
Action type: Habitat management
Duration: >10 years
Scale of Implementation: 1 site
High priority sites: Ducan's Fen SSSI Norfolk (TG339027)
Comments: The site is private and managed by a conservation trust.
Key Action 3
Proposed Action: Suction sampling of other M13 mires would seem useful to see if more populations exist. Its minute size preciates against easy detection.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: 2 years
Scale of Implementation: ≤ 10 sites
High priority sites: Known areas of M13 mire
Comments: Short scale surveying to protect any extant populations
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.