Steatoda nobilis
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| Species: | S. nobilis
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| Steatoda nobilis (Thorell, 1875)
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Steatoda nobilis is a spider in the genus Steatoda, commonly known in England as the noble false widow.[1][2] or false widow.[3] As the common name indicates, the spider superficially resembles and is frequently confused for the black widow and other spiders in the genus Latrodectus, which can have medically significant venom. S. nobilis is native to Madeira and the Canary Islands from where it allegedly spread to Europe,[4] and arrived in England before 1879, perhaps through bananas sent to Torquay.[5] In England it has a reputation as one of the few local spider species which is capable of inflicting a painful bite to humans.[6]
Description
Steatoda nobilis has a brown bulbous abdomen with cream coloured markings that are often likened to the shape of a skull.[7] The legs are reddish-orange.[8] Females range in size from about 9.5 to 14 mm in size, while males are 7 to 11 mm.[1] Males are able to produce stridulation sounds during courtship, by scraping 10-12 teeth on the abdomen against a file on the rear of the carapace.
Distribution, habitat and ecology
The spider is an introduced species across Europe, plus parts of North Africa, and likely spreading. It was found for the first time in 2011 in Cologne, Germany.[9] It is originally from the Canary Islands and Madeira.[10] In England it has been reported mostly in southern counties,[11][12] but its range appears to be expanding northwards.[13][14] In 2011, the spider was reported as an established invasive species in the USA, in Ventura County, California.[15]
As with other members of the family Theridiidae, Steatoda nobilis constructs a cobweb which is an irregular tangle of sticky silken fibres. Its 'scaffold web' differs from others of the genus in the exceptional strength of the silk, and in the tubular retreat that is at least partly concealed in a deep crack or hole.[12] They have poor eyesight and depend mostly on vibrations reaching them through their webs to orient themselves to prey or warn them of larger animals that could injure or kill them.
Population expansion in UK
The distribution of S. nobilis is expected to increase northwards in the UK, due at least partly to mild summers in recent years. This prediction was reported by Stuart Hine of the Natural History Museum,[16] and is substantiated by the National Recording Scheme.[12]
Medical significance
Like almost all spiders, Steatoda nobilis is venomous, but the bite is almost exclusively of mild effect on humans, without severe consequences that can present from black widow spiders. Its bite is often alleged to be one of the medically significant for humans, even though the few recorded bites do not typically present long-lasting effects. The symptoms of a bite are typically similar to a bee or wasp sting.[8] The bite of this spider, along with others in the genus Steatoda, can produce a set of symptoms known as steatodism. Symptoms of bites include intense pain radiating from the bite site, along with feverishness or general malaise.[17] Only the female spider bites humans.[3]
Sensationalized stories about the bite of Steatoda nobilis have featured in UK newspaper articles. Stuart Hine from the Natural History Museum, London responded on the naturenet blog, stating, "Of course I also explain the great value of spiders and how rare the event of spider bite in the UK actually is. I also always explain that up to 12 people die from wasp/bee stings in the UK each year and we do not panic so much about wasps and bees – but this never makes it past editing." [16] Steven Falk, an entomologist, cautioned that without "hard evidence", it is difficult to know how many of the bites reported in the media have been caused by false widow spiders.[18]
Alleged incidents
- In 2006 a Dorchester man spent three days in Dorset County Hospital with symptoms of heart seizure, after suffering a spider bite believed to be caused by Steatoda nobilis.[6]
- In 2012 a man collapsed in Southampton after apparently being bitten on his neck. He had complained of feeling hot, queasy and light headed. He required treatment in hospital, where it was discovered that he had been bitten 10 times on the neck, allegedly by the same large spider. The spider (which had been trapped in the victim's hooded jacket) was caught and tentatively identified by health workers as Steatoda nobilis.[19]
- In 2012 a woman in Dorset suffered serious effects after her hand was supposedly bitten by a false widow spider.[20]
- In 2013 a man in Sidcup of London was allegedly bitten in his sleep, reporting that his hand had turned black and yellow. His hand remained swollen for five weeks until doctors gave him a course of antibiotics.[21]
- Later in 2013 a man is said to have required emergency surgery to open up and flush out his leg tissue in order to remove the toxin left there after being bitten by Steatoda nobilis, following his disturbance of a "nest of false widows" in Romford, Essex[22]
References
- ^ a b Snazell, R. and Jones, D. (1993). "The theridiid spider Steatoda nobilis (Thorell, 1875) in Britain". Bulletin British Arachnological Society. 9 (5): 164–167.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Jones, D. (1993). "The Return of Steatoda nobilis (Thorell)". Newsletter of the British Arachnological Society. 49: 7–8.
- ^ a b "False widow spider, Steatoda nobilis". Natural History Museum. Retrieved 11 October 2013.
- ^ Kulczycki, A., Legittimo, C.M., Simeon, E. and Di Pompeo, P. (2012). "New records of Steatoda nobilis (Thorell, 1875) (Araneae, Theridiidae), an introduced species on the Italian mainland and in Sardinia". Bulletin British Arachnological Society. 15 (8): 269–272.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Octavius Pickard-Cambridge (1879). "On some new and rare British spiders, with characters of a new genus". Annals and Magazine of Natural History. 5 (4): 109–215.
- ^ a b David Sapsted (17 November 2006). "Watch out, the black widow's sister is ready to bite you". Daily Telegraph. London.
- ^ Sebastian Salek (24 September 2013). "More sightings of the false widow spider, as Britain's 'most venomous arachnid', with orange legs and white skull markings spotted in Essex". The Independent. London.
- ^ a b "Noble false widow spider marches north in the UK". Natural History Museum. Retrieved 11 October 2013.
- ^ "Observation by C Wieczorrek". 15 December 2006. Retrieved 22 November 2012.
- ^ "World Distribution Map of S. Nobilis". British Arachnological Society. Sept/Oct 2012. Retrieved 22 Nov 2012.
{{cite web}}: Check date values in:|date=(help) - ^ Harvey, P.R., Nellist, D.R. and M.G. Telfer, ed. (2002). Provisional Atlas of British spiders (Arachnida, Araneae). Vol. 1 &2. Huntingdon: Biological Records Centre.
{{cite book}}: CS1 maint: multiple names: editors list (link) - ^ a b c "Summary for Steatoda nobilis (Araneae)". British Arachnological Society: National Recording Scheme. 2010–2012. Retrieved 22 Nov 2012.
{{cite web}}: CS1 maint: date format (link) - ^ "Biting spider widens its web". BBC News. 2001-09-21.
- ^ "Warning over rise in UK's most dangerous spider due to warmer winters". MailOnline. 2 May 2007.
- ^ "European Spider, Steatoda nobilis Theridiidae". University of California, Riverside. Retrieved 11 October 2012.
- ^ a b "The Ranger's Blog: The truth about Steatoda nobilis - is it the UK's most dangerous spider?". 2 May 2007. Retrieved 22 November 2012.
- ^ Warrell, D.A., Shaheen, J., Hillyard, P. D. & D. Jones (1991). "Neurotoxic envenoming by an immigrant spider (Steatoda nobilis) in southern England". Toxicon. 29 (10): 1263–1265. doi:10.1016/0041-0101(91)90198-Z. PMID 1801319.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ "False widow spider bites footballer Steve Harris". BBC News. 10 October 2013. Retrieved 10 October 2013.
- ^ "Father collapses after being bitten 10 times by the UK's most venomous spider after it falls into his HOOD". Daily Mail. London.
- ^ Luke Salkeld (18 April 2012). "'I nearly lost my hand to Britain's most poisonous spider': Woman bitten while she SLEPT by close relative of deadly Black Widow that lives in UK". Daily Mail. Retrieved 22 November 2012.
- ^ "Bites reported across London and Kent as south east sees influx of Britain's most poisonous spider". The Independent. 19 September 2013. Retrieved 04 October 2013.
{{cite news}}: Check date values in:|accessdate=(help) - ^ "Decorator suffers horrific wound inflicted by poisonous spider that is plaguing Britain". Daily Mail. London.
External links
