Pentaphyllus testaceus
Key Details
| Taxonomic Groups: | Invertebrate > insect - beetle (Coleoptera) > Darkling beetle or ally |
| 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: | Pentaphyllus testaceus |
| UKSI Recommended Authority: | (Hellwig, 1792) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Alexander et al., 2014 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | Until recently, only known as British on the basis of one found in a decaying fruiting body of ‘Polyporus squamosus’ placed as a trap in the hollow trunk of a partially decayed oak in a hedgerow in fields at Crouch End, Hornsey, North London, June 1876 – a rural area at the time. Discovered in Windsor Great Park in 2001 and Langley Park in 2006. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Minimum intervention management will not provide conditions suitable for the development of successive generations of veteran trees, and well-planned tree planting remains the exception rather than the rule. |
| 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 species would not benefit from untargeted management |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 7. Best approach adopted at appropriate scales |
| Recovery potential/expectation: | Low - Relict or natural rarity |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | Develops in large volumes of red-rotten wood retaining its integrity and some moisture, with abundant sheets of Laetiporus sulphureus mycelia along fracture lines; freshly exposed heartwood of recently fallen oak trees or major boughs – appears to require a stable environment in which humidity levels are unvarying and a supply of its fungal food is long-lasting. It is stated to feed on fungal spores and hyphae. Apparently constantly full-winged although none has ever been taken in flight traps; clearly dispersal flights must be few, and probably only when the habitat has been disturbed by fracture of the trunk with consequent drying. |
Key Actions
Key Action 1
Proposed Action: Create a UK DNA sequence, and primers to allow eDNA sampling.
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 2 years
Scale of Implementation: 1 site
High priority sites: Windsor Forest
Comments: To allow less invasive detection in saproxylic substrates. This can run in parallel with Action 2.
Key Action 2
Proposed Action: At sites where the species occurs document age structure for potential host veteran trees and future veterans, to determine whether there is an adequate rate of replacement. Also assess requirements for management of the veteran tree stock to reduce the risk of wind throw, by undertaking tree surgery to reduce the crown of excessive bough weighting.
Action targets: 7. Best approach adopted at appropriate scales
Action type: Targeted monitoring
Duration: 2 years
Scale of Implementation: ≤ 5 sites
High priority sites: Windsor Great Park (Berkshire) and Langley Park (Buckinghamshire)
Comments:
Key Action 3
Proposed Action: Subject to the results of Action 1, plant trees or promote natural regeneration on sites where there has been insufficient recruitment of younger age classes.
Action targets: 7. Best approach adopted at appropriate scales
Action type: Habitat management
Duration: >10 years
Scale of Implementation: ≤ 20 sites
High priority sites: Prioritisation is subject to assessment of tree age structure at all sites where the species occurs
Comments: Either planting or natural regeneration should not be allowed to create crown competition or cast shade on existing veteran trees. If there is no space within a site to achieve this, then planting on adjacent land may also be a priority.
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.