Chrysotoxum vernale

Key Details

Taxonomic Groups: Invertebrate > insect - true fly (Diptera) > Hoverfly
Red List Status: Endangered (Not Relevant) [EN(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: Chrysotoxum vernale
UKSI Recommended Authority: Loew, 1841
UKSI Recommended Qualifier: (none specified)
Red List Citation: Ball & Morris, 2014
Notes on taxonomy/listing: (none)

Criteria

Question 1: Does species need conservation or recovery in England?
Response: Yes
Justification: Rare and vulnerable with modern records confirmed to a small number of coastal heathland areas of the Studland area (picked up through the Cyril Diver Project) and seemingly lost from areas such as the New Forest and former locations in Cornwall. Near Threatened in Europe (IUCN).
Question 2: Does recovery/ conservation depend on species-specific actions?
Response: Yes
Justification: Poor understanding of its specific needs beyond an association with coastal heath and a likely association of its larvae with ant-attended root aphids (though specific ant associations do not seem to be known - members of the Lasius flavus group have been suggested on the continent).
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: It clearly requires good quality open heathland/coastal grassland with varied vegetation structure and a variety of flowers to forage on.

Species Assessment

Current step on the Species Recovery Curve (SRC): 4. Autecology and pressures understood
Recovery potential/expectation: Low - Relict or natural rarity
National Monitoring Resource: Opportunistic - insufficient
Species Comments: Needs targeted surveying/monitoring on all Dorset heaths.

Key Actions

Key Action 1

Proposed Action: Specific targeted surveying/monitoring in its key area to investigate the extent of populations and whether there are specific habitat needs on Dorset heaths (simultaneously with C. octomaculatum) to feed into a revisions of the Red List assessment.

Action targets: 2. Biological status assessment exists

Action type: Status survey/review

Duration: 2 years

Scale of Implementation: ≤ 20 sites

High priority sites: Dorset heaths esp Studland area

Comments:

Key Action 2

Proposed Action: More research needed into the ant fauna of sites where the species does occur and whether management is having a detrimental impact on the abundance and diversity of Formicidae. Monitoring of breeding areas may help elucidate host-specific relationships

Action targets: 4. Autecology and pressures understood

Action type: Scientific research

Duration: 2 years

Scale of Implementation: ≤ 10 sites

High priority sites: Dorset heaths esp Studland area

Comments: Action 2 field work could be carried out alongside Action 1 and other Chrysotoxum species

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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.