Xysticus ulmi

This record describes Xysticus ulmi (species). Recorded family: Thomisidae. Recorded order: Araneae.

Identification and Appearance

The broad cross line across its abdomen is characteristic. A sexually dimorphic species, with the male being much darker than the female. It is very similar to X. cristatus though usually has a more elongated abdomen. The epigyne and male palpal organs are the distinctive features. Confirmation requires microscopic examination of the genitalia of adult specimens. Identification of this species Requires examination at high magnification in good lighting, typically examination of the genitalia. Bee, L., Oxford, G., & Smith, H. (2020). Britain's Spiders: A Field Guide. Second Edition. Princeton University Press. Does not build a web but lies in wait for prey. Quite common and widespread in most of England and Wales, but less frequent further north.

Classification

Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Family: Thomisidae
Genus: Xysticus

Imported taxonomy record. Source availability varies; see the source references and editorial policy below.

Habitat and Range

Habitat

This crab spider prefers damp habitats.

Seasonal Activity

Seen mainly in spring and early summer.

Diet and Behavior

Life History

Does not build a web but lies in wait for prey.

Additional species information

Recorded status

though usually has a more elongated abdomen. The epigyne and male palpal organs are the distinctive features.

About Spiders: the wider group

Order-level background for Araneae, the group containing Xysticus ulmi. Species-specific details appear above.

Group overview

As of 2023, 51,673 spider species in 136 families have been recorded, though an estimated 150,000 species exist. Spiders rank 7th in total species diversity among all organism orders. Only 0.5% of spider species pose any risk to human health.

Ecological role of the group

Spider venom contains complex peptides with diverse pharmacological activities, making them valuable for drug development research. Spiders produce up to 7 types of silk from specialized glands. Spider silk genes have been inserted into mammals and plants for biotech applications.

Economic and practical significance of the group

The global spider community kills an estimated 400-800 million tons of prey annually (2017 study). Spiders provide billions of dollars in natural pest control for agriculture. Spider silk is 5× stronger than steel of the same diameter, driving a biomaterials research industry.

Recorded sources for this group: World Spider Catalog, PNAS, Nature, ScienceDirect. Imported estimates may describe particular regions or reporting periods.

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