Devon Red-legged Robberfly (Neomochtherus pallipes)
Key Details
| Taxonomic Groups: | Invertebrate > insect - true fly (Diptera) > Soldier fly 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: | Neomochtherus pallipes |
| UKSI Recommended Authority: | (Meigen, 1820) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Drake, 2017 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | First English record from Devon in 1990, then a single record from Berkshire in 2012 followed by a new population being discovered in Shropshire in 2016. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | There are specific known sites for the species that need surveying to ascertain the presence or not of the species. The two main sites vary in that the original Devon site was dry, sandy cliff top grassland, on the South coast whilst the Shropshire records had sandy soil but were inland with surrounding trees. Ecological study is needed to ascertain the exact habitat niche before more specific actions can be implemented. Both sites are very hot, with a particular aspect, which suggests species is thermophilus and requires very free draining substrates. Key to create comparable geological assessment of other nearby sites for exploration |
| 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: | (Unable to state without further ecology/habitat details) |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Low - Life history factor/s |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | It is difficult to suggest the recovery potential without further information on populations and biology. The need for sandy soil and dry grassland would fit in with both main sites although the geography and latitude varies significantly. Assessment of soil types and underpinning geology ought to drive this, together with aspect as heat looks to be important. Likely short flight period makes it tricky. |
Key Actions
Key Action 1
Proposed Action: Tailored surveys of potential habitat in and around known localities to determine the population and species distribution, thus identifying areas if N. pallipes is present.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: 2 years
Scale of Implementation: ≤ 5 sites
High priority sites: Shropshire, Haughmond Hill (SJ537137), Berkshire, Dry Sandford Pit (SU467995), Devon, Woodcombe, Prawle Point (SX79493649)
Comments: A tailored survey within the known flight period to encompass the areas where previous sightings have been made along with any adjacent/linked areas with similar habitats to see if populations are still present before specific actions can be identified.
Key Action 2
Proposed Action: Assessment of occupied sites (based on outcomes of Action 1) and those adjacent unoccupied sites, to explore habitat niche and any see if any specific requirements can be identified.
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: ≤ 20 sites
High priority sites: Shropshire, Haughmond Hill (SJ537137), Berkshire, Dry Sandford Pit (SU467995), Devon, Woodcombe, Prawle Point (SX79493649)
Comments:
Key Action 3
Proposed Action: Once sites are identified from Actions 1 and 2 then protection of dry sandy areas and grassland through management of scrub and woodland edge to prevent shading and encroachment.
Action targets: 2. Biological status assessment exists
Action type: Habitat management
Duration: >10 years
Scale of Implementation: ≤ 20 sites
High priority sites: Shropshire, Haughmond Hill (SJ537137), Berkshire, Dry Sandford Pit (SU467995), Devon, Woodcombe, Prawle Point SSSI (SX79493649)
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.