Forest Silver-stiletto (Pandivirilia melaleuca)
Key Details
| Taxonomic Groups: | Invertebrate > insect - true fly (Diptera) > Soldier fly or ally |
| 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: | Pandivirilia melaleuca |
| UKSI Recommended Authority: | (Loew, 1847) |
| 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: | Found in three main areas, Berkshire (Windsor Forest), Worcestershire in two sites and more recently (2024) two sites in S. Essex (Epping Forest). This shows an expansion in range but the fly is still scarce, with only 10 records in the past 10 years. The fly is scarce throughout all of its European range. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | The more widespread habitat is within wood pasture and parklands with ancient trees, that are becoming scarcer or are 'managed' for public safety that is potentially destroying the necessary habitat niche for the species to survive. Education of land managers and protection of the existing habitat is crucial. |
| 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: | This species would not benefit from untargeted management |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 4. Autecology and pressures understood |
| Recovery potential/expectation: | Low - Life history factor/s |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | The larvae require red-rotten oak or rotten beech to develop, preying on larvae of moths and beetles. Old, decaying, rotting trees are critical. |
Key Actions
Key Action 1
Proposed Action: There are very recent (if few) records from Worcestershire and S. Essex; with the S. Essex records being a new area, surveying of suitable habitat across the country from Essex to Worcestershire may show a more realistic view of the distribution and population size.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: 3-5 years
Scale of Implementation: ≤ 100 sites
High priority sites: Initially known site and suitable environs; Worcestershire, Lower Moor River Meadows (SO974469); S. Essex, Epping Forest (TQ399955, TQ405963), Berkshire, Wytham Woods (SP464079) and also Worcestershire, Berrow (SO777339) which has regular older records between 2013 & 2019) Windsor forest has even older records so may be worth checking.
Comments: The survey should concentrate on larval searches, mindful of the fragility of the habitat, and the larvae recorded and some reared. This might help in better keys and should certainly be retained for eDNA work to assist in future bulk sample detections.
Key Action 2
Proposed Action: With protection of ancient trees in park and wood pasture being critical, provide advice and guidance to land managers, especially in public access sites, to prevent loss of even more ancient/decaying trees.
Action targets: 5. Remedial action identified
Action type: Advice & support
Duration: 3-5 years
Scale of Implementation: ≤ 20 sites
High priority sites: Initially known site and suitable environs; Worcestershire, Lower Moor River Meadows (SO974469); S. Essex, Epping Forest (TQ399955, TQ405963), Berkshire, Wytham Woods (SP464079) and also Worcestershire, Berrow (SO777339) which has regular older records between 2013 & 2019) Windsor forest has even older records so may be worth checking.
Comments: The approach being based around information, training and support for land managers to help implement any guidance. More specifically with regard to old orchards and old fruit trees that are at risk of being destroyed either to be replaced for commercial planting or for development i.e housing, bus lanes, industrial units, roads.
Key Action 3
Proposed Action: Derive a new larval key from rearing to enable accurate larval identification, together with eDNA sequencing. This might enable the true distribution picture to be better understood.
Action targets: 4. Autecology and pressures understood
Action type: Other (specify in comments)
Duration: 3-5 years
Scale of Implementation: Not applicable
High priority sites: No specifics at this time however as a general action these sites are important for many invertebrates and birds so any that are found during surveys should be assessed for risk to their continued existence and if possible protection put in place.
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.