Xysticus cristatus

Xysticus cristatus, the common crab spider,[2] is a European spider from the family Thomisidae.[1]

Xysticus cristatus
Female
Male with prey
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Thomisidae
Genus: Xysticus
Species:
X. cristatus
Binomial name
Xysticus cristatus
(Clerck, 1757)[1]
Synonyms[1]
  • Araneus cristatus Clerck, 1757
  • Aranea viatica Linnaeus, 1758
  • Aranea nasuta Martini & Goeze, 1778
  • Aranea fasciata Fourcroy, 1785
  • Aranea horticola Olivier, 1789
  • Aranea cristata (Clerck, 1757)
  • Aranea liturata Fabricius, 1793
  • Aranea subreptans Strack, 1810
  • Thomisus viaticus (Linnaeus, 1758)
  • Thomisus cristatus (Clerck, 1757)
  • Xysticus viaticus (Linnaeus, 1758)
  • Xysticus cristatus (Clerck, 1757)
  • Xysticus augur Strand, 1900
  • Xysticus sexangulatus Strand, 1900

Description

The adult female reaches a length of 8mm and the smaller male 5mm.[2] The colour varies from light cream, dark brown to greyish[3] with a dark triangle on the carapace which ends in sharp, defined point. The abdomen has a broad middle band fringed by two darker rows of triangular marks[2] which extends back to about two thirds of the carapace length from the posterior row of eyes.[4] This cryptic colouration is used to blend in with its normal environment of dried leaves.[5] The common name crab spider arises because they sometimes move in a crab-like way, from side to side.[3]

Habitat

Xysticus cristatus is usually found in low vegetation, often on the ground.[2] It is shade intolerant and avoids woodland and closed canopy habitats but it is otherwise found in almost every habitat type.[6]

Biology

Xysticus cristatus is an ambush hunter which spends much time sitting still, with its fore-legs spread wide, waiting for insects to blunder into them.[3] In grass it adopts a flexible hunting position either at the tips of vegetation, such as flowerheads, or on the ground surface and as a result, the prey taken is varied and is made up of flying insects, including bees and butterflies. When it hunts on the ground the food tends to consist of ants, spiders and other soft bodied prey. It often takes prey much larger than itself.[3] In Great Britain spiderlings balloon, most often between the months of July to September. Active adults have been recorded from February to December, with a peak of male activity in May and June.[6]

To mate the male grasps one of the female's legs, holding on until she ceases to struggle, he then uses silk to tie her down on the ground and then he crawls underneath her and mates.[2]

In Britain Xysticus cristatus has been observed as a prey item for the spider wasp Dipogon bifasciatus.[7]

Distribution

The species has a Palearctic distribution,[1][8] being found throughout Europe, including Iceland.[9]

gollark: "Oh yes, I will just go OUTSIDE the universe" - statements made by GTech™ exploration probe #15996-υ/4.
gollark: Where else would they go?
gollark: What? Of course they are in our universe.
gollark: Those aren't heaven and hell, silly.
gollark: > The temperature of Heaven can be rather accurately computed from available data. Our authority is Isaiah 30:26, “Moreover, the light of the Moon shall be as the light of the Sun and the light of the Sun shall be sevenfold, as the light of seven days.” Thus Heaven receives from the Moon as much radiation as we do from the Sun, and in addition seven times seven (49) times as much as the Earth does from the Sun, or fifty times in all. The light we receive from the Moon is one ten-thousandth of the light we receive from the Sun, so we can ignore that. With these data we can compute the temperature of Heaven. The radiation falling on Heaven will heat it to the point where the heat lost by radiation is just equal to the heat received by radiation, i.e., Heaven loses fifty times as much heat as the Earth by radiation. Using the Stefan-Boltzmann law for radiation, (H/E)^4 = 50, where E is the absolute temperature of the earth (-300K), gives H as 798K (525C). The exact temperature of Hell cannot be computed, but it must be less than 444.6C, the temperature at which brimstone or sulphur changes from a liquid to a gas. Revelations 21:8 says “But the fearful, and unbelieving … shall have their part in the lake which burneth with fire and brimstone.” A lake of molten brimstone means that its temperature must be at or below the boiling point, or 444.6C (Above this point it would be a vapor, not a lake.) We have, then, that Heaven, at 525C is hotter than Hell at 445C. – “Applied Optics”, vol. 11, A14, 1972

References
  1. "Xysticus cristatus (Clerck, 1757)". World Spider Catalog. Natural History Museum Bern. Retrieved 18 September 2016.
  2. "Common Crab Spiders". uksafari.com. Retrieved 17 September 2016.
  3. "Xysticus cristatus - Xysticus cristatus". naturespot.org.uk. Retrieved 17 September 2016.
  4. "Xysticus cristatus (Clerck, 1757) (Common ground crab spider)". University of Copenhagen/Natural History Museum, Aarhus. Retrieved 17 September 2016.
  5. "Common Crab Spider – Xysticus cristatus". Pete Hillman. Retrieved 17 September 2016.
  6. "Summary for Xysticus cristatus". British Arachnological Society. Retrieved 17 September 2016.
  7. Edwards, R.; Broad, G. (2005). Provisional Atlas for the aculeate Hymenoptera of Britain and Ireland. Bees, Wasps and Ants Recording Society. ISBN 1 870393 78 3.
  8. "Xysticus cristatus (Clerck, 1757)". GBIF.org. Retrieved 17 September 2016.
  9. "Xysticus cristatus (Clerck, 1757)". araneae Spiders of Europe. Retrieved 17 September 2016.
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