CRCritically Endangered

saksische fopwesp

Chrysotoxum verralli

The saksische fopwesp (Chrysotoxum verralli) is a critically endangered hoverfly species belonging to the family Syrphidae. This distinctive yellow and black striped fly mimics wasps as a defense mechanism against predators, a behavior known as Batesian mimicry.

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Countries

01Classification

Taxonomy & Classification

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Syrphidae

Genus

Chrysotoxum

saksische fopwesp belongs to the family Syrphidae, order Diptera, within the Insecta class.

02Description

Species Profile

The saksische fopwesp (Chrysotoxum verralli) is a critically endangered hoverfly species belonging to the family Syrphidae. This distinctive yellow and black striped fly mimics wasps as a defense mechanism against predators, a behavior known as Batesian mimicry. The species is endemic to specific regions of the Netherlands, where it inhabits sandy heathlands and open woodland areas with sparse vegetation. Adult flies are active during summer months and feed on nectar from various flowering plants, while larvae develop in ant nests where they feed on debris and possibly ant larvae. The species has experienced severe population declines and is now considered one of Europe's rarest hoverflies. Primary threats include habitat loss due to agricultural intensification, urban development, and changes in land management practices that have reduced suitable heathland environments. The decline of traditional grazing practices has led to vegetation succession that makes habitats unsuitable for the species. Climate change may also impact the delicate ecological relationships between the fly, its host plants, and associated ant species. Conservation efforts focus on habitat restoration and management of remaining heathland sites, including controlled grazing and scrub removal to maintain open sandy areas. Monitoring programs have been established to track remaining populations, though the species' cryptic nature and specific habitat requirements make detection challenging. Collaboration between conservation organizations and land managers is essential for implementing targeted management strategies.

The saksische fopwesp faces severe threats from habitat loss caused by agricultural expansion and urban development that have destroyed much of its specialized sandy heathland habitat. Changes in traditional land management practices, particularly the decline of extensive grazing, have allowed vegetation to become too dense for the species' requirements. Climate change may further disrupt the complex ecological relationships this species depends on for survival.

Key Facts

IUCN StatusCritically Endangered (CR)
GroupInsects
03Habitat

Habitat & Distribution

This species inhabits sandy heathlands and open woodland areas with sparse vegetation, particularly sites with exposed sandy soils and scattered flowering plants. The larvae specifically require ant nests for development, making the presence of suitable ant species essential for breeding success.

04Threats

Threats

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IUCN Red List: Critically Endangered

The saksische fopwesp faces severe threats from habitat loss caused by agricultural expansion and urban development that have destroyed much of its specialized sandy heathland habitat. Changes in traditional land management practices, particularly the decline of extensive grazing, have allowed vegetation to become too dense for the species' requirements. Climate change may further disrupt the complex ecological relationships this species depends on for survival.

Detailed threat classification data is sourced from IUCN assessments as they become available.

07National Status

National vs Global Threat Status

How this species is assessed at the national level compared to its IUCN global status (CR).

CountryNational StatusGlobal StatusComparison
EULCLeast ConcernCRCritically EndangeredLower local risk
EULCLeast ConcernCRCritically EndangeredLower local risk

National Red List data sourced from the National Red List Project (nationalredlist.org, ZSL) and country-specific Red List authorities.

Community

Community Sightings

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07Sources

Sources & Attribution

How to Cite

IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS

GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org

National Red Lists: ZSL (2025). National Red List. Zoological Society of London. Available at: https://www.nationalredlist.org

This page: SpeciesRadar (2025). saksische fopwesp (Chrysotoxum verralli). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/saksische-fopwesp

Full citation guide & data usage terms