Bromius obscurus
Key Details
| Taxonomic Groups: | Invertebrate > insect - beetle (Coleoptera) > Leaf beetle or ally |
| Red List Status: | Critically Endangered (Not Relevant) [CR(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: | Bromius obscurus |
| UKSI Recommended Authority: | (Linnaeus, 1758) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Hubble, 2014 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | Only known from a small number of sites |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Lack of evidence |
| 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: | Given the habitat of known populations, the creation of habitat mosaics across the landscape would possibly benefit this species. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Medium-high |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | The extremely unusual distribution of this species is suggestive of a possible introduction prior to when it was first added to the British list in 1831. Sub-fossil remains from the late glacial period are widespread across the UK, but there are no recent sub-fossil remains. The root-feeding larvae can be easily transported via the horticultural trade. It is also parthenogenetic, so a population can quickly be established from a single founder. The popularity of ornamental gardening in the 18th and 19th century and the associated transport of plants from continental Europe could be the source of the current UK populations of this species. Investigating the population genetics of the populations would establish if this is the case. |
Key Actions
Key Action 1
Proposed Action: Targeted survey of known and similar sites
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Status survey/review
Duration: 2 years
Scale of Implementation: ≤ 20 sites
High priority sites: Sites with suitable habitat
Comments: This species is fairly distinctive and can be conspicuous. Feeds on Rosebay willowherb Chamerion angustifolium and great willowherb Epilobium hirsutum growing in generally eutrophic grassland sites. The adults feed on the foliage of the host-plants, while the larvae are root feeders. In other parts of range it feeds on Rubus and Vitis and is often considered to be a pest. In Canada it is a notifiable pest of Rubus roses and grapes.
Key Action 2
Proposed Action: Define autecology of larvae and adults at known sites. Population genetics of known populations
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites: Rushton Spencer area (Staffordshire/Cheshire), Crosby Grange (Scunthorpe area), Jupiter Reserve (Stirlingshire),
Comments: Important questions to try and answer with targeted research include: Population genetics to understand if this species was accidentally introduced. What do the larvae need? What are the dispersal abilities of the adults? How will existing populations be impacted by climate change.
Key Action 3
Proposed Action: Raise awareness among the public of this species as it's a fairly distinctive and conspicuous species and would be noticed by casual observers. Given recent findings, other populations are probably to be discovered.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Education/awareness raising
Duration: 2 years
Scale of Implementation: National
High priority sites: N/A
Comments: Partner with relevant organisations to highlight this species in apps and explore other channels to target casual observers
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.