graskrabspin
Xysticus erraticus
Xysticus erraticus, commonly known as the graskrabspin, is a small crab spider characterized by its cryptic coloration that allows it to blend seamlessly with grass stems and flower heads. This ambush predator plays a crucial role in grassland ecosystems by controlling populations of flying insects, particularly pollinators and small flies that it captures while remaining motionless on vegetation.
29
Countries
Taxonomy & Classification
Kingdom
Animalia
Phylum
Arthropoda
Class
Arachnida
Order
Araneae
Family
Thomisidae
Genus
Xysticus
graskrabspin belongs to the family Thomisidae, order Araneae, within the Arachnida class.
Species Profile
Xysticus erraticus, commonly known as the graskrabspin, is a small crab spider characterized by its cryptic coloration that allows it to blend seamlessly with grass stems and flower heads. This ambush predator plays a crucial role in grassland ecosystems by controlling populations of flying insects, particularly pollinators and small flies that it captures while remaining motionless on vegetation.
Xysticus erraticus faces significant population declines primarily due to habitat loss and degradation of its specialized grassland and heathland environments. Agricultural intensification, urban development, and changes in land management practices have severely reduced the availability of suitable habitat for this ground-dwelling spider species.
Key Facts
Habitat & Distribution
Graskrabspin inhabits species-rich grasslands, meadows, and prairie edges where it positions itself on the flower heads of native plants such as wild carrot, goldenrod, and various composite flowers. The species shows a strong preference for areas with moderate grazing pressure that maintain a mosaic of grass heights and abundant flowering plants throughout the growing season.
Threats
IUCN Red List: Endangered
Xysticus erraticus faces significant population declines primarily due to habitat loss and degradation of its specialized grassland and heathland environments. Agricultural intensification, urban development, and changes in land management practices have severely reduced the availability of suitable habitat for this ground-dwelling spider species.
Habitat loss due to agricultural intensification
Urban and infrastructure development
Changes in grassland management practices
Climate change affecting habitat suitability
Habitat fragmentation
Found in 29 Countries
Community Sightings
Report a sightingNo community sightings yet. Be the first to report!
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
This page: SpeciesRadar (2025). graskrabspin (Xysticus erraticus). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/graskrabspin