The female grows to a length of around 8 mm whilst the male is a little smaller, growing to around 5 mm and much darker. In both sexes, the dark triangle on the carapace ends in sharp, defined point. The abdomen has a broad middle band bordered by two darker rows of triangular marks. Microscopic examination of the genitalia is necessary to confirm identification.
Xysticus ulmi is similar but lacks the sharp and dark point at the end of the triangle on the carapace. It is also found in damper habitats.
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.
This species occurs on the ground or in low vegetation.
March to August but mainly seen in spring and early summer.
Spends much time sitting still, with its fore-legs spread wide, waiting for insects to blunder into them. Predatory on other invertebrates, including ants, which most other spiders avoid, and often taking prey much larger than themselves. Called 'crab spiders' because, as the name suggests, they sometimes move in a crab-like way, from side to side. The male has an unusual method of mating with the female. First he grabs hold of one of her legs and waits until she stops struggling. He then ties her down to the ground with threads of silk. Finally he crawls underneath her to mate.
Very common and widespread throughout Britain.
Common in Leicestershire and Rutland.
12086 British records to Jan 2013
Leicestershire & Rutland Map
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Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015