Minutest Diving Beetle (Bidessus minutissimus)
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: | Bidessus minutissimus |
| UKSI Recommended Authority: | (Germar, 1823) |
| 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: | The most recent record is from 2009, from a quarry in Presteigne, Herts (Foster et al, 2016). It has always been an extreme rarity in England but there are more records from Wales and Scotland. This is an example of a species which would be categorised as CR in an England-only context. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Yes' if considered purely in an English context. However, Bidessus minutissimus has at best an extremely small toehold in England; conservation action might be best focussed in central Wales. |
| 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: | Bidessus minutissimus is an extreme rarity in England so would not benefit from generic measures. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 3. National Monitoring Plan agreed and implemented |
| Recovery potential/expectation: | Unknown |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | 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: Selective resurvey of historic sites where suitable habitat still exists, in order to determine the current status of B. minutissimus in England. If successful, surveys should identify potential pressures on sites. Practical implementation will depend on the outcome of surveys.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Status survey/review
Duration: 1 year
Scale of Implementation: ≤ 5 sites
High priority sites: English records come from a single recent location in Herefordshire and two historic sites in South Devon.
Comments:
Key Action 2
Proposed Action: If the species is re-discovered in England as a result of Action 1, consider appropriate conservation action in liaison with country agencies in Wales and Scotland where the species is better established.
Action targets: 5. Remedial action identified
Action type: Advice & support
Duration: 3-5 years
Scale of Implementation: Unknown
High priority sites:
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.