Biology Coursework Wood Lice Hunting Spider

The woodlouse spider, Dysdera crocata, is a species of spider that preys primarily upon woodlice. Other common names refer to variations on the common name of its prey, including woodlouse hunter, sowbug hunter, sowbug killer, pillbug hunter and slater spider.


Female specimens are 15–30 mm long, while males are 10–15 mm. They have six eyes, a dark-red cephalothorax and legs, and a shiny (sometimes very shiny) yellow-brown abdomen. Notably, they have disproportionately large chelicerae for a spider of this size. Dysdera crocata is difficult to distinguish from the much less common Dysdera erythrina[1] though this species is not often found near human habitation.


D. crocata, which originated in the Mediterranean area, now has a cosmopolitan distribution (see map), ranging from Eurasia to parts of North and South America, South Africa, Australia, and New Zealand.[2]


Woodlouse spiders are usually found under logs, rocks, bricks, and in leaf litter in warm places, often close to woodlice. They have also been found in houses. They spend the day in a silken retreat made to enclose crevices in, generally, partially decayed wood, but sometimes construct tent-like structures in indents of various large rocks. Woodlouse spiders hunt at night and do not spin webs.

Their diet consists principally of woodlice which—despite their tough exoskeleton—are pierced easily by the spider's large chelicerae; the spider usually stabs and injects venom into the woodlouse's soft underbelly while avoiding any noxious defensive chemicals.[2] Laboratory experiments have shown D. crocata will take other invertebrates, and shows no particular preference for woodlice; these are simply the most common prey in its habitat.[2] Other invertebrates preyed on by D. crocata include silverfish, earwigs, millipedes, and small burying beetles. This small but huge-fanged spider is very well equipped to prey on underground invertebrates of almost any kind.

Because of its gigantic fangs and wide gape, the woodlouse spider is an unusually dominant predator for its size. Like many other Dysdera spiders, it frequently dominates, and sometimes kills, other spiders and centipedes.

The courtship of these spiders is typically aggressive and mates risk injury from each other's large chelicerae. The female lays her eggs in a silken sac and is believed to look after her young after hatching.

They have been known to bite humans if handled. Verified bites have caused no major medical problems. Localized itchiness at the bite site has been reported in some cases.[3]


External links[edit]

Further reading[edit]

  1. ^Cooke, J. A. L. (June 1965), "Systematic aspects of the external morphology of Dysdera crocata and Dysdera erythrina (Araneae, Dysderidae)", Acta Zoologica, 46 (1-2): 41–65, doi:10.1111/j.1463-6395.1965.tb00726.x 
  2. ^ abcVink, Cor J. (2015). A Photographic Guide to Spiders of New Zealand. Auckland: New Holland. p. 29. ISBN 978-1-86966-403-9. 
  3. ^Vetter, R. S.; Isbister, G. K. (2006). "Verified bites by the woodlouse spider, Dysdera crocata". Toxicon. 47 (7): 826–829. doi:10.1016/j.toxicon.2006.02.002. PMID 16574180. 

Home » Guide » Arthropods (Arthropoda) » Chelicerates (Chelicerata) » Arachnids (Arachnida) » Spiders (Araneae) » True Spiders (Araneomorphae) » Haplogynes » Dysderids (Dysderidae) » Dysdera » Woodlouse Hunter (Dysdera crocata)

Species Dysdera crocata - Woodlouse Hunter

Classification · Other Common Names · Synonyms and other taxonomic changes · Explanation of Names · Numbers · Identification · Range · Food · Life Cycle · Remarks · See Also · Internet References · Works Cited


Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Chelicerata (Chelicerates)
Class Arachnida (Arachnids)
Order Araneae (Spiders)
Infraorder Araneomorphae (True Spiders)
No Taxon (Haplogynes)
Family Dysderidae (Dysderids)
Genus Dysdera

Species crocata (Woodlouse Hunter)

Other Common Names

Sow Bug Hunter, Pill Bug Hunter, Stiletto spider

Synonyms and other taxonomic changes

See the World Spider Catalog.

Explanation of Names

The genus name originates from the 2nd century B.C. poet Nicander.

Greek adjective: 'hard to fight against'. Cameron(2005)(1)


The only member of the family in NA.




Fighting pair

Eye Arrangement


Introduced to North America and widely distributed in the Nearctic.(1). Originally from the Mediterranean area.


Primary prey is isopods; hence the large chelicerae and fangs.

Life Cycle

This species is reported to take up to a year and half to mature, and live an additional two to three years in captivity.(1)


A six-eyed spider.

Regarding the bite of this spider:

"Bites by the woodlouse spider, Dysdera crocata, are virtually innocuous. The main symptom is minor pain, typically lasting less than 1 hr, probably due mostly to the mechanical puncture of the skin."

- Vetter, R. & Isbister, G. 2006. Verified bites by the woodlouse spider, Dysderacrocata. Toxicon 47 (2006) 826-829.

See Also

Similar coloring to genus Trachelas

Internet References

Penn State University

Pub.Med. Verified bites by the woodlouse spider, Dysdera crocata. Vetter, RS, Isbister, GK.



Works Cited

1.Spiders of North America: An Identification Manual
D. Ubick, P. Paquin, P.E. Cushing and V. Roth (eds). 2005. American Arachnological Society.

Contributed by Troy Bartlett on 13 April, 2004 - 6:23pm
Additional contributions by Beatriz Moisset, Lynette Elliott, Christopher C Wirth, Jeff Hollenbeck, cheins, Chuck Entz, Graham M, jsloan, metrioptera
Last updated 4 August, 2017 - 8:15am

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