Cheilosia semifasciata
Key Details
| Taxonomic Groups: | Invertebrate > insect - true fly (Diptera) > Hoverfly |
| 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: | Cheilosia semifasciata |
| UKSI Recommended Authority: | (Becker, 1894) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Ball & Morris, 2014 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | Seems to be very restricted. Within England seemingly only recently recorded from Shropshire. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Use of specific foodplants (Navelwort and Orpine). |
| 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: | Yes |
| Justification: | Management is required to promote the two foodplants in abundance but also encouraging them to grow in a variety of microclimates, because the fly may be highly selective about location and is clearly much rarer than the foodplants. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 4. Autecology and pressures understood |
| Recovery potential/expectation: | Low - Relict or natural rarity |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | Could be generally under-recorded in the Welsh Marches, so needs more targeted surveying of both adults (April) and leaf mines (summer). |
Key Actions
Key Action 1
Proposed Action: Establish its current distribution through field survey (concentrating on the Welsh Marches and working with local botanists) to feed into a revision of the Red List assessment
Action targets: 2. Biological status assessment exists
Action type: Status survey/review
Duration: 3-5 years
Scale of Implementation: Not applicable
High priority sites: Shropshire, Herefordshire and Worcestershire.
Comments: Some sites are known but under-recording suspected so a need to survey as many Navelwort or Orpine-rich areas in the Welsh Marches as possible.
Key Action 2
Proposed Action: Train local botanists/naturalists to spot leaf mines or adults to further knowledge on the status of the species and feed into a possible revision of the Red List.
Action targets: 2. Biological status assessment exists
Action type: Education/awareness raising
Duration: 3-5 years
Scale of Implementation: Not applicable
High priority sites: Shropshire, Herefordshire and Worcestershire.
Comments: Some aspects of surveying probably do not require an experienced entomologist e.g. looking for leaf mines.
Key Action 3
Proposed Action: Autecological research into whether the foodplant is required in specific settings e.g. sunny and sheltered locations, through field surveys
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: Not applicable
High priority sites: Shropshire, Herefordshire and Worcestershire.
Comments: Recording habitat parameters of occupied and unoccupied stands of navelwort
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.