Western Wood-vase Hoverfly (Myolepta potens)
Key Details
| Taxonomic Groups: | Invertebrate > insect - true fly (Diptera) > Hoverfly |
| 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: | Myolepta potens |
| UKSI Recommended Authority: | (Harris, [1780]) |
| 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: | Only extant population known is at Moccas Park, Herefordshire though |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Conservation requires protection of specific old Horse Chestnut trees featuring water-filled rot holes (for larval development). See also recent Back from the Brink activity here: file:///D:/S.%20Falk%20Documents/Information%20-%20Insects/Diptera/Syrphidae/Myolepta/Western-Wood-vase-Hoverfly-BftB.pdf |
| 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: | Requires a sufficient number of suitable old trees for a viable population, and also a good age structure of trees to ensure further trees eventually attain suitability. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 6. Recovery solutions trialled |
| Recovery potential/expectation: | Low - Relict or natural rarity |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | Has been subject to formal surveys but these are not ongoing. |
Key Actions
Key Action 1
Proposed Action: Map suitable breeding trees through field survey in and around hotspots plus continued monitoring of the fly to investigate the extent of populations.
Action targets: 2. Biological status assessment exists
Action type: Status survey/review
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites: Moccas Park and Forest of Dean.
Comments: Some work already carried out recently at Moccas Park through the Ancients of the Future project.
Key Action 2
Proposed Action: Targeted in-person land management advice and support for landowners and tree managers on recognising and protecting key habitats features (mature trees and umbellifer flowers for adult foraging), and providing these into the future.
Action targets: 5. Remedial action identified
Action type: Advice & support
Duration: 1 year
Scale of Implementation: ≤ 5 sites
High priority sites: Moccas Park and Forest of Dean
Comments: Some of this has already taken place through the Back from the Brink project.
Key Action 3
Proposed Action: Plant more Horse Chestnuts to ensure a future continuity of suitable trees in the long-term future (some has already been carried out through Back from the Brink work but it is unclear if more planting in and around Moccas park is still needed.
Action targets: 5. Remedial action identified
Action type: Habitat creation
Duration: 1 year
Scale of Implementation: ≤ 5 sites
High priority sites: In and around Moccas Park.
Comments: Some of this has already taken place through the Back from the Brink project. Exact locations within Moccas Park 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.