Cyrnus insolutus
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: | Cyrnus insolutus |
| UKSI Recommended Authority: | McLachlan, 1878 |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Wallace, 2016 |
| Notes on taxonomy/listing: | A few additional larval sites (mainly Welsh) are thought to be probably aberrantly marked Cyrnus flavidus but this needs confirming. |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | IUCN status awarded as there were no modern records but would now qualify for Critically Endangered and even possibly extinct due to the total loss of one of its sites (Padworth Oval Pond|), the continued failure to find it at its other site (Blelham Tarn) and no additional sites being discovered. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | There are currently no known sites and the proposed actions are to remedy that situation. This is such a rare species that presumably if it was re-discovered at Blelham efforts would be made to enhance the amount of its particular habitat. |
| 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 is such a rare species that it seems unlikely it could take advantage of general habitat diversification of ponds and lakes. At Blelham management to increase structural diversity of the shore-line should be encouraged. The larvae used to be found on the rocky shore and the amount of this has declined in the 50 years Ian Wallace has known the site. Rare caddis Erotesis baltica and Anabolia brevipennis occur on the site and presumably other rare aquatic invertebrates. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Low - Relict or natural rarity |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | There were only ever two English and GB sites (Blelham Tarn and Padworth Oval Pond). Padworth has been destroyed by Turkish crayfish that seem to have eliminated all caddis not just this rarity and Blelham Tarn has not produced any records for decades (last record circa 1965). The habitat at its sites may be very site specific which is why the recommendation focussing particularly on restoring rocky shore must be regarded as tentative. It should be noted that other rare caddis and presumably other rare invertebrates occur at Blelham. |
Key Actions
Key Action 1
Proposed Action: Survey Blelham Tarn for larvae and adults, noting carefully the microhabitat if any are found to inform future site management.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: 2 years
Scale of Implementation: 1 site
High priority sites: Blelham tarn
Comments: Padworth and Blelham seem different ecologically and are geographically spaced so that it is difficult to focus speculative traditional surveys elsewhere. worth it. However, it may be encountered in general surveys, possibly if done using eDNA.
Key Action 2
Proposed Action: Undertake literature search and make email enquiries to see if this species has been recorded in eDNA surveys. If answer is yes, then method used could be translated to look for it in other sites such as in the Lake District, as well as Blelham Tarn.
Action targets: 2. Biological status assessment exists
Action type: Scientific research
Duration: 2 years
Scale of Implementation: ≤ 5 sites
High priority sites: Blelham Tarn
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.