Xysticus viduus Kulczyński, 1898
Description
Male
Male palp with 2 tegular apophyses, median one with massive, large tip pointing to prolateral anterior margin of tibia, second branch small and hook-shaped. Lateral apophysis horn-like shaped, with lobe-like process on posterior edge. Tibial apophysis bipartite, ventral apophysis strongly projecting retrolaterally, with apical median groove. Retrolateral apophysis long and tapering toward the tip in ventral view, with wart-shaped protrusion on tip.
Prosoma dark brown with median, broad, cream stripe. Eye field bright, beige-brown. Sternum cream median part and dark brown to yellow-brown on margin. Chelicerae spined. Legs brown, dorsally darker with bright longitudinal stripes. Opisthosoma oval, brown to dark brown, with white anterior margin, with broad, white folium. Spinnerets brown.
Female
Epigyne with very large, broad and shallow groove, which is distinctly marked off by heart-shaped sclerotised ridge. Vulva consists of 2 wide entrance ducts. With compact and small chelicerae. Opisthosoma oval, grey-beige, with white anterior margin, with broad, white folium, that can be diffuse. Opisthosoma . Spinnerets: cream beig.
Body length female: 5.3-8.2 mmAdditional information
In vegetationless gravel plains and in pioneer-vegetation near water borders
Distribution
Figures
Pedipalp
(Miller & Zitnanska 1976)
Pedipalp, ventral view
(Thaler & Knoflach 1995b)
Pedipalp, ventral view
(Miller & Zitnanska 1976)
Pedipalp, ventral view
(Azheganova 1968)
Pedipalp, ventral view
(Jantscher 2001a)
Pedipalp
(Thaler & Knoflach 1995b)
Pedipalp, retrolateral view
(Jantscher 2001a)
Epigyne
(Miller & Zitnanska 1976)
Epigyne
(Miller & Zitnanska 1976)
Epigyne
(Miller & Zitnanska 1976)
Epigyne
(Thaler & Knoflach 1995b)
Epigyne
(Thaler & Knoflach 1995b)
Epigyne
(Azheganova 1968)
Epigyne
(Jantscher 2001a)
Epigyne
(Jantscher 2001a)
Vulva, dorsal view
(Jantscher 2001a)
Vulva, dorsal view
(Jantscher 2001a)
Distribution List
"No references" does not mean that the species does not occur in this country, but that we have not yet inserted the reference for it. We are working on it.
References
Azheganova N S (1968) Kratkii opredelitel' paukov (Aranei) lesnoi i lesostepnoi zony SSSR. Akademia Nauk SSSR, 149pp. 
Blick T, Finch O-D, Harms K H, Kiechle J, Kielhorn K-H , Kreuels M, Malten A, Martin D, Muster C, Nährig D, Platen R, Rödel I, Scheidler M, Staudt A, Stumpf H, Tolke D (2016) Rote Liste und Gesamtartenliste der Spinnen (Arachnida: Araneae) Deutschlands. 3. Fassung, Stand April 2008, einzelne Änderungen und Nachträge bis August 2015. Naturschutz und Biologische Vielfalt 70/4: 383-510
Danışman T, Kunt K B, Özkütük R S, Coşar İ (2025a) The checklist of the spiders of Turkey. Version 2025 [last updated 22 July 2025], online at http://www.spidersofturkey.info
Esyunin S L, Efimik V E (1996a) Catalogue of the spiders (Arachnida, Aranei) of the Urals. KMK Scientific Press, Moscow, 228 pp.
Gajdoš P, Svatoň J, Sloboda J (1999) Katalóg pavúkov Slovenska. Catalogue of Slovakian spiders. Ústav kr. ekol. SAV, Bratislava, 337 pp.
Hänggi A, Stäubli A (2012) Nachträge zum „Katalog der schweizerischen Spinnen“: 4. Neunachweise von 2002 bis 2011. Arachnologische Mitteilungen 44: 59-76
Ivanov V V (2013) The checklist of Belarusian spiders (Arachnida, Araneae). Zoology and Ecology 4: 293-311
Jantscher E (2001a) Revision der Krabbenspinnengattung Xysticus C.L. Koch, 1835 (Araneae, Thomisidae) in Zentraleuropa. Dissertation, Univ. Graz, 328 pp., 81 pls.
Koponen S, Fritzén N R, Pajunen T (2016) Checklist of spiders in Finland (Araneae). 6th version, December 2016, online at http://biolcoll.utu.fi/arach/checklist_of_spiders_in_Finland.htm
Koponen S, Marusik Y M, Tanasevitch A V (1998) New data on the spider fauna of the Polar Urals (Aranei). Arthropoda Selecta 6: 109-119
Miller F, Zitnanska O (1976) Einige bemerkenswerte Spinnen aus der Slowakei. Biológia (Bratislava) 31: 81-88
Otto S (2022) Caucasian spiders. A faunistic database on the spiders of the Caucasus Ecoregion. Database version 02.2022. Internet: caucasus-spiders.info.
Polchaninova N, Prokopenko E (2019) An updated checklist of spiders (Arachnida: Araneae) of Left-Bank Ukraine. Arachnologische Mitteilungen 57: 60-64 & App
Ponomarev A V (2022) Spiders (Arachnida: Araneae) of the southeast of the Russian Plain: catalogue, the fauna specific features. SSC RAS Publishers, Rostov-on-Don, 640 pp.
Thaler K, Knoflach B (1995b) Xysticus obscurus Collett - eine arktoalpine Krabbenspinne neu für Österreich (Arachnida, Araneida: Thomisidae). Berichte des Naturwissenschaftlich-Medizinischen Vereins in Innsbruck 82: 145-152
Thaler K, Knoflach B (2004b) Zur Faunistik der Spinnen (Araneae) von Österreich: Gnaphosidae, Thomisidae (Dionycha pro parte). Linzer Biologische Beiträge 36: 417-484
Weiss I, Petrișor A (1999) List of the spiders (Arachnida: Araneae) from Romania. Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa” 41: 79-107
WSC (2025) World Spider Catalog. Version 26. Natural History Museum Bern, online at http://wsc.nmbe.ch (28.2.2025) doi: 10.24436/2