Caliprobola speciosa
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: | Caliprobola speciosa |
| UKSI Recommended Authority: | (Rossi, 1790) |
| 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: | All of UK population concentrated within old Beech woodland of the New Forest and Windsor Great Park/Forest area. Poor dispersal abilities (has not been recorded from apparently suitable sites elsewhere e.g. Burnham Beeches or Wytham Woods). Concern over long-term continuity of breeding habitat (Beech stumps in appropriate locations) and adult forage (especially Hawthorn blossom). No evidence of increase in New Forest but good recent data showing where it currently occurs here. Some concern over possible decrease at Windsor. Localised in Europe (but Least Concern). |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Concern over long-term continuity of breeding habitat (Beech stumps in appropriate locations) and conflicts with other activities such as tree planting around breeding stumps (which can shade them out) or grazing pressure on Beech saplings by stock and deer (reducing long-term prospects for site suitability). |
| 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 develop a better age structure of the Beech so that there is a regular, long term supply of old or dead trees; also the need to increase adult forage such as flowering Hawthorn and umbellifers. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 5. Remedial action identified |
| Recovery potential/expectation: | Unknown |
| National Monitoring Resource: | Structured - insufficient |
| Species Comments: | Subject to recent structured monitoring in the New Forest (see https://caliprobola.maploom.com/info) but not in the Windsor area. |
Key Actions
Key Action 1
Proposed Action: Identify current breeding areas (Beech stumps and old living Beech with heartrot in sunny locations) through field surveys, and protect these against loss, damage or shading out, now and in the future.
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites: These are the New Forest (numerous location across the National Park) and the Windsor Great Park area (several locations within this large area)
Comments: Volunteers are currently identifying breeding areas within the New Forest but not actively protecting them as such. Over-grazing and insensitive tree planting have been identified as issues.
Key Action 2
Proposed Action: Targeted in-person land management advice and support for landowners on recognising and protecting key habitat features, and providing these into the future.
Action targets: 7. Best approach adopted at appropriate scales
Action type: Advice & support
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites: These are the New Forest (numerous locations across the National Park) and the Windsor Great Park area (several locations within this large area)
Comments: Key landowners/parties are Forestry England and New Forest National Park Authority for the New Forest and the Crown Estates for Windsor.
Key Action 3
Proposed Action: Plant Beech and Hawthorn (with protection from grazing) in appropriate locations (more open areas of woodland) to increase the extent and quality of its two strongholds.
Action targets: 6. Recovery solutions trialled
Action type: Habitat management
Duration: >10 years
Scale of Implementation: ≤ 5 sites
High priority sites: These are the New Forest (numerous locations across the National Park) and the Windsor Great Park area (several locations within this large area). In the New Forest this includes the Denny Wood and Mark Ash areas. At Windsor, this includes High Standing Hill.
Comments: Exact locations within the areas given are not known, and should be decided upon in conjunction with species experts and land managers
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.