Agabus striolatus
Key Details
| Taxonomic Groups: | Invertebrate > insect - beetle (Coleoptera) > Water beetle |
| Red List Status: | Vulnerable (Not Relevant) [VU(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: | Agabus striolatus |
| UKSI Recommended Authority: | (Gyllenhal, 1808) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Foster, 2010 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | A. striolatus has a highly restricted GB distribution (c. 9 hectads) and specialised habitat requirements. This distribution is likely to be a remnant of a once wider range rather than it being inherently rare. It appears to be a highly sedentary species so is unlikely to naturally recolonise sites from which it is lost. Most known sites are in Broadland and vulnerable to sea level rise in the long term. In a GB context, A. striolatus occurs only in England. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | A. striolatus is sufficiently rare that loss of any single population would increase national extinction risk. Furthermore, it depends on small, shallow, seasonal pools and runnels, in deep shade and often filled with decaying leaves. The value of this niche is easily overlooked. |
| 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: | A. striolatus is too rare and localised to benefit from 'wider countryside' interventions. It is potentially at risk from inappropriate application of generic management prescriptions such as scrub removal in fens. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Unknown |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | While it is possible that additional sites await discovery, it's unlikely that A. striolatus would be found outside Norfolk and the Humberhead Peatlands, both of which have been well surveyed. Monitoring known populations is a greater priority than more extensive searching for this species. Ad hoc recording as part of GB water beetle recording scheme (Balfour-Browne Club/Aquatic Coleoptera Conservation Trust) |
Key Actions
Key Action 1
Proposed Action: Re-survey known sites with a view to recording the extent of populations (where this is uncertain), in order to provide targeted advice to site managers (most if not all sites will be SSSIs and managed by conservation organisations). Retention of shade or dense tussock vegetation is important for this species.
Action targets: 5. Remedial action identified
Action type: Status survey/review
Duration: 2 years
Scale of Implementation: ≤ 50 sites
High priority sites: Sites are clustered in Broadland, with one site in Norfolk outside the Broads and Inkle Moor Fen in South Yorkshire. Records have been mapped in Atlas 1 (Foster et al, 2016).
Comments: Survey work would be best co-ordinated with the Aquatic Coleoptera Conservation Trust.
Key Action 2
Proposed Action: Consider this species and its requirements in SSSI and nature reserve management plans, water level management plans etc, and consider opportunities for listing this species as a site 'feature' (e.g. review of SSSI citations).
Action targets: 5. Remedial action identified
Action type: Pressure mitigation
Duration: 2 years
Scale of Implementation: National
High priority sites: All known sites
Comments:
Key Action 3
Proposed Action: Undertake a review of this species and other water beetles dependent on relict-fens in order to promote better understanding of their conservation requirements. A. striolatus belongs to a suite of water beetles closely associated with remnant fens; others include Dryops anglicanus, D. auriculatus, D. griseus, Helochares obscurus, Hydrochus brevis, H. ignicollis, H. megaphallus, Hydroporus elongatulus, H. glabriusculus, H. scalesianus, Laccornis oblongus and Limnebius aluta. Agabus striolatus has more distinctive ecological requirements than some of these (hence the need for actions A1 & A2), but nonetheless belongs to this wider ecological group.
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 1 year
Scale of Implementation: Not applicable
High priority sites:
Comments: Desk-based study/literature and data review.
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.