Dytiscus dimidiatus
Key Details
| Taxonomic Groups: | Invertebrate > insect - beetle (Coleoptera) > Water beetle |
| 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: | Dytiscus dimidiatus |
| UKSI Recommended Authority: | Bergsträsser, 1777 |
| 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: | No |
| Justification: | Although D. dimidiatus has been lost from northern England, it has expanded in East Anglia during the past 25 years and has recently been recorded (probably as a vagrant) from Scotland. It is capable of natural range expansion, being a strong flyer, though opportunities may be constrained by habitat quality. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | No |
| Justification: | Dytiscus dimidiatus is potentially capable of natural recovery and is currently increasing following decline during the late 20th century, though individual sites may be at risk (e.g., in Wales, the Gwent Levels). Natural recolonisation of the Humberhead Levels and Vale of York would represent a significant recovery in its historic English range and monitoring should be encouraged (e.g. at Thorne Moors and Strensall Common) but this cannot be considered a national priority. |
| 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: | N/A |
| Justification: |
Species Assessment
Not relevant as no Key Actions defined.
Key Actions
No Key Actions Defined
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.