Window Winged Sedge (Hagenella clathrata)
Key Details
| Taxonomic Groups: | Invertebrate > insect - caddis fly (Trichoptera) > Caddisfly |
| Red List Status: | Endangered (Not Relevant) [EN(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: | Hagenella clathrata |
| UKSI Recommended Authority: | (Kolenati, 1848) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Wallace, 2016 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | There are very few modern sites and it seems potentially at risk at all of them due to habitat deterioration. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | It's habitat is destroyed by general re-wetting associated with carbon sequestration, and also by grazing to eliminate Molinia tussocks |
| 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: | It should be possible to accommodate increasing its specific habitat needs into general bog restoration plans but in the long term it should benefit from more habitat being created we just have to keep it going until that habitat comes of age and is suitable. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 4. Autecology and pressures understood |
| Recovery potential/expectation: | Medium-high |
| National Monitoring Resource: | Combination - insufficient |
| Species Comments: | The attractive day-flying adult makes this the obvious choice as the flagship caddis for conservation of caddis and also of its sites. There is potentially a lot of habitat available and it could be encouraged at all its sites and even be introduced / re-introduced to neighbouring sites. At the moment its prospects do not look good but the proposed actions could give us information to change that situation. |
Key Actions
Key Action 1
Proposed Action: Set up monitoring programme for adults at various sites. There is enthusiasm by management at its two major English sites of Whixall and Chartley to set up a regular adult monitoring programme and there is regular opportunistic surveys of Surrey / Hampshire sites. (Nothing currently at Roudsea).
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites: Whixall Moss, Chartley Moss, Whitmoor Common, Hawley Common
Comments: Can be meshed with transects for other day-flying insects. Note that surveying at Roudsea Moss for adults is not possible as the site is inaccessible due to being adjacent to an osprey nesting platform.
Key Action 2
Proposed Action: Undertake a very detailed study of the physical features and water table within the Molinia tussock habitat and other pools where the larvae are found. The reason it is so restricted at each site is not known and this information may help to solve that and new areas within its sites to which it could be translocated identified.
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites: Whixall Moss, Chartley Moss, Whitmoor Common and Hawley Common
Comments:
Key Action 3
Proposed Action: Devise a captive breeding programme to provide stock to re-inforce site populations by setting up breeding in areas identified from action as suitable.
Action targets: 6. Recovery solutions trialled
Action type: (Re-)introduction
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites:
Comments: This species has proved frustratingly unwilling to move within its sites to what appears superficially to be suitable habitat within those major sites.
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.