Forest Windowfly (Scenopinus niger)
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: | Scenopinus niger |
| UKSI Recommended Authority: | (De Geer, 1776) |
| 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: | Numerous records from 2014 to 2021 but these are from a limited amount of sites. The consensus from NERC 192 2017 was that it may be under recorded due to its lifestyle and difficult to find. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Little information available on ecology/biology of S. niger. Whilst there are a few sites where it was recorded on multiple occasions the habitat where it was found is fairly generic in being wooded parkland or woodland. Added to the fact that the fly is supposedly quite secretive and difficult to find the initial actions may be restricted to a few known sites. |
| 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): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Low - Life history factor/s |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | Larvae are 'likely' to need heart-rot, rot-holes and bracket fungi on veteran oak and beech. Adults are rarely caught and apart from multiple records from a few known sites distribution is widespread but with few records in general |
Key Actions
Key Action 1
Proposed Action: Tailored surveys of the required habitat in the adult flight period (May-June) to be completely sure whether the previous populations are present and where possible in suitable sites both habitat and latitude considered (South of the Humber at this point in time, although climate change may change this), that have little previous history of surveying.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: 2 years
Scale of Implementation: ≤ 50 sites
High priority sites: Shropshire, Millichope Park (SO52358860) Lower Brompton (SJ55610804), Avon, Bristol, Henbury Parkland (ST556784), Nottinghamshire, Clumber (SK626751), Buckinghamshire, Ivanhoe Common (SP978144) If a national approach can be taken then this will hopefully increase the number of sites surveyed substantially.
Comments: May be best approached nationally through recording scheme or Dipterist's forum as well as specifically targeting known sites.
Key Action 2
Proposed Action: With protection of ancient trees in parks and woodland appearing to be 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: Shropshire, Millichope Park (SO52358860) Lower Brompton (SJ55610804), Avon, Bristol, Henbury Parkland (ST556784), Nottinghamshire, Clumber (SK626751), Buckinghamshire, Ivanhoe Common (SP978144) If a national approach can be taken then this will hopefully increase the number of sites surveyed substantially.
Comments: The approach being based around information, training and support for land managers to help implement any guidance. Actions 1 & 2 may lead to further precise actions in relation to the fly's ecological requirements.
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.