Editing Redback spider (section)

==Distribution and habitat==
[[File:Redback spider records map.png|thumb|A distribution map of the records of redback spider specimens reported to the [[Atlas of Living Australia]] as of September 2013.]]
The redback spider is widespread across Australia. The current distribution reported by the World Spider Catalogue includes Southeast Asia and New Zealand.<ref name=WSC_s39048/> Colonies and individuals have been found elsewhere, including Japan,<ref>{{Cite news|url=https://www.independent.co.uk/life-style/health-and-families/health-news/venomous-aussie-redback-spiders-invading-japan-5508922.html|title=Venomous Aussie redback spiders invading Japan|date=25 November 2009|work=The Independent|access-date=30 March 2018|language=en-GB|archive-date=30 March 2018|archive-url=https://web.archive.org/web/20180330081529/https://www.independent.co.uk/life-style/health-and-families/health-news/venomous-aussie-redback-spiders-invading-japan-5508922.html|url-status=live}}</ref><ref>{{Cite news|url=http://www.abc.net.au/news/2014-10-20/redback-spiders-found-for-the-first-time-in-tokyo/5827612|title=Redback spiders found in Tokyo for first time|date=20 October 2014|work=ABC News|access-date=30 March 2018|language=en-AU|archive-date=4 January 2021|archive-url=https://web.archive.org/web/20210104063414/https://www.abc.net.au/news/2014-10-20/redback-spiders-found-for-the-first-time-in-tokyo/5827612|url-status=live}}</ref> England, Belgium, the United Arab Emirates and Iran.<ref name=WhytAnde17/><ref name="distributions paper" /><ref name="Slaughter" /><ref name="MAF" /> It was believed at one time that the redback may have been introduced to Australia, because when it was first formally described in 1870, it appeared to be concentrated around sea ports.<ref name="garb 2004">{{cite journal|last=Garb|first=Jessica E.|author2=González, Alda|author3=Gillespie, Rosemary G.|title=The Black Widow Spider Genus ''Latrodectus'' (Araneae: Theridiidae): Phylogeny, Biogeography, and Invasion History|journal=Molecular Phylogenetics and Evolution|date=June 2004|volume=31|issue=3|pages=1127–42|doi=10.1016/j.ympev.2003.10.012|url=http://nature.berkeley.edu/~gillespie/Publications_files/GarbGonzGillMPE.pdf|pmid=15120405|bibcode=2004MolPE..31.1127G |access-date=9 September 2013|archive-date=21 September 2013|archive-url=https://web.archive.org/web/20130921060650/http://nature.berkeley.edu/~gillespie/Publications_files/GarbGonzGillMPE.pdf|url-status=live}}</ref><ref name=RaveGall87>{{Cite book |last1=Raven |first1=R.J. |last2=Gallon |first2=J.A. |date=1987 |editor1-last=Covacevich |editor1-first=J. |editor2-last=Davie |editor2-first=P. |editor3-last=Pearns |editor3-first=J. |contribution=The redback spider |title=Toxic Plants and Animals : A Guide for Australia |pages=307–11 |location=Brisbane |publisher=Queensland Museum |name-list-style=amp }}</ref> However, an earlier informal description (1850) from the Adelaide Hills is now known, and names in [[Australian Aboriginal languages]] also show that it was present well before European settlement. Its original range is thought to be a relatively small arid part of South Australia and Western Australia.<ref name=WhytAnde17>{{Cite book |last1=Whyte |first1=Robert |last2=Anderson |first2=Greg |date=2017 |title=A Field Guide to Spiders of Australia |publisher=CSIRO Publishing |isbn=978-0-643-10707-6 |name-list-style=amp }} p. 339.</ref> Its spread has been inadvertently aided by modern buildings, which often provide habitats conducive to redback populations.{{sfn|Brunet|1997|p=148}} The close relationship between the redback and the New Zealand [[katipō]] also supports the native status of both in their respective countries.<ref name="Forster95"/>

Outside urban areas, the redback is more often found in drier habitats ranging from [[sclerophyll]] forest to desert, even as harsh as the [[Simpson Desert]].{{sfn|Brunet|1997|p=148}} It became much more common in urban areas in the early decades of the 20th century,{{sfn|McKeown|1963|p=188}} and is now found in all but the most inhospitable environments in Australia and its cities.{{sfn|Brunet|1997|p=148}} It is particularly common in [[Brisbane]], [[Perth]] and [[Alice Springs]].<ref name=Nimorakiotakis>{{cite journal|author1=Nimorakiotakis, B.|author2=Winkel, K.D.|year=2004|title=Spider bite – the redback spider and its relatives|url=http://www.racgp.org.au/afpbackissues/2004/200403/20040311winkel.pdf|journal=Australian Family Physician|volume=33|issue=3|pages=153–57|pmid=15054982|access-date=18 October 2013|archive-date=19 October 2013|archive-url=https://web.archive.org/web/20131019144016/http://www.racgp.org.au/afpbackissues/2004/200403/20040311winkel.pdf|url-status=live}}</ref> It is wide spread throughout urban Australia, with most suburban backyards in the city of Canberra (for instance) having one or more nesting females in such places as firewood piles, stored brick stacks and around unused or restoring motor vehicles as well as generally behind the shed - as observed since at least the 1970s and probably earlier. The redback spider is commonly found in close proximity to human residences. Webs are usually built in dry, dark, sheltered sites, such as among rocks, in logs, tree hollows, shrubs, old tyres, sheds, outhouses, empty tins and boxes, children's toys or under rubbish or litter.<ref name=SMH1907/><ref name="Amo-Redback"/><ref name="autogenerated3">{{cite news |url=http://nla.gov.au/nla.news-article39366487 |title=Beware the Red-Back spider. |newspaper=[[Western Mail (Western Australia)|Western Mail]] |location=Perth |date=18 March 1954 |page=3 |publisher=National Library of Australia |access-date=4 September 2013 |archive-date=19 October 2021 |archive-url=https://web.archive.org/web/20211019062747/https://trove.nla.gov.au/newspaper/article/39366487 |url-status=live }}</ref> Letterboxes and the undersurface of toilet seats are common sites.{{sfn|Brunet|1997|p=148}} Populations can be controlled by clearing these habitats,<ref name=CentralianAdvocate/> squashing the spiders and their egg sacs,<ref name=Warden1989/> and using pesticide in outhouses.<ref name=CentralianAdvocate>{{cite news |url=http://nla.gov.au/nla.news-article59838671 |title=Redback Plague Continues. |newspaper=Centralian Advocate |location=Alice Springs, NT |date=26 January 1951 |page=13 |publisher=National Library of Australia |access-date=4 September 2013 |archive-date=19 October 2021 |archive-url=https://web.archive.org/web/20211019062748/https://trove.nla.gov.au/newspaper/article/59838671 |url-status=live }}</ref> The [[Commonwealth Scientific and Industrial Research Organisation|CSIRO]] Division of Entomology recommends against the use of spider pesticides due to their toxicity, and because redbacks are rapid recolonists anyway.<ref name=Warden1989/>

Spiders in the French territory of [[New Caledonia]] in the Pacific were identified as ''L. hasselti'' in 1920, based on morphology. Their behaviour differs from Australian redbacks, as they do not engage in sexual cannibalism and are less prone to biting humans. The first recorded [[envenomation]] in New Caledonia was in 2007.<ref name=Maillaud>{{cite journal|last=Maillaud|first=Claude|author2=Jourdan, Hervé |author3=Winkel, Ken |author4=Arnaud, Gaëlle |author5=Lafforgue, Patrick |author6= Durand, Francis |title=Latrodectism in New Caledonia: First Report of Presumed Redback Spider (''Latrodectus hasselti'') Envenomation|journal=Wilderness & Environmental Medicine|date=1 December 2009|volume=20|issue=4|pages=339–43|doi=10.1580/1080-6032-020.004.0339|pmid=20030441|doi-access=free}}</ref>

===Introductions===
The redback spider's affinity for human-modified habitat has enabled it to spread to several countries via international shipping and trade. Furthermore, its tolerance to cold means that it has the ability to colonise many temperate countries with a winter climate cooler than Australia. This is concerning due to the risks to people being bitten who are unaware of its venomous nature, and also to the conservation of local threatened insect species that the redback might prey upon.<ref name="distributions paper"/>

Redback spiders are also found in small colonies in areas of New Zealand. They are frequently intercepted by quarantine authorities, often among steel or car shipments.<ref name="distributions paper">{{Cite journal | last1 = Vink | first1 = C. J. | last2 = Derraik | first2 = J. G. B. | last3 = Phillips | first3 = C. B. | last4 = Sirvid | first4 = P. J. | title = The Invasive Australian Redback Spider, ''Latrodectus hasseltii'' Thorell 1870 (Araneae: Theridiidae): Current and Potential Distributions, and Likely Impacts | doi = 10.1007/s10530-010-9885-6 | journal = Biological Invasions | volume = 13 | issue = 4 | pages = 1003–19 | year = 2010 | s2cid = 1887942 }}</ref> They were introduced into New Zealand in the early 1980s,<ref>{{citeQ|Q130183406}}</ref> and now are found around Central [[Otago]] (including [[Alexandra, New Zealand|Alexandra]], [[Bannockburn, New Zealand|Bannockburn]] and near [[Wānaka]]) in the South Island and [[New Plymouth]] in the North Island.<ref name="distributions paper"/><ref name="Slaughter"/><ref name="MAF">{{cite report |author1=Reed, C. |author2=Newland, S. |author3=Downs, J. |author4=Forbes, V. |author5=Gilbert, S. |title=MAF Biosecurity Pest Risk Assessment: Spiders Associated With Table Grapes From United States of America (State of California), Australia, Mexico and Chile |publisher=MAF Biosecurity |date=September 2002 |url=http://www.biosecurity.govt.nz/files/regs/imports/risk/spiders-grapes-ra.pdf |access-date=18 February 2007 |archive-url=https://web.archive.org/web/20100523183538/http://www.biosecurity.govt.nz/files/regs/imports/risk/spiders-grapes-ra.pdf |archive-date=23 May 2010 |url-status=dead  }}</ref> Authorities in the United Arab Emirates warn residents and visitors of redback spiders, which have been present since 1990.<ref>{{cite web|url=http://gulfnews.com/news/gulf/uae/environment/redback-spiders-are-back-don-t-panic-urges-dubai-municipality-1.1155440|title=Redback Spiders are Back: Don't Panic, urges Dubai Municipality|first=Mariam M.|last=Al Serkal|date=7 March 2013|access-date=1 September 2013|archive-date=27 September 2013|archive-url=https://web.archive.org/web/20130927121939/http://gulfnews.com/news/gulf/uae/environment/redback-spiders-are-back-don-t-panic-urges-dubai-municipality-1.1155440|url-status=live}}</ref> Colonies have also been established in greenhouses in Belgium{{cn|date=April 2025}}, and isolated observations indicate possible presence in [[New Guinea]], the Philippines, and India.<ref name="distributions paper"/> Some redbacks were found in [[Preston, Lancashire]], England, after a container of parts<!--what kind of parts?--> arrived from Australia; some may have escaped into the countryside before pest controllers could destroy them.<ref name="Metro">{{cite web | publisher= Metro | title= Deadly Australian Spiders 'invading' the UK, one Field at a Time | url= http://www.metro.co.uk/weird/832600-deadly-australian-spiders-invading-the-uk-one-step-at-a-time | date= 24 June 2010 | access-date= 24 June 2010 | archive-date= 26 June 2010 | archive-url= https://web.archive.org/web/20100626002010/http://www.metro.co.uk/weird/832600-deadly-australian-spiders-invading-the-uk-one-step-at-a-time | url-status= live }}</ref> One redback was found in a back garden in [[Borough of Dartford|Dartford]] in [[Kent]].<ref name='Kent"2014"'>{{cite news|last1=Clarke-Billings|first1=Lucy|title=Deadly spider that can kill with one bite found in a back garden in KENT|url=https://www.mirror.co.uk/news/uk-news/deadly-spider-can-kill-one-4715326|access-date=28 November 2014|work=Daily Mirror|date=28 November 2014|archive-date=28 November 2014|archive-url=https://web.archive.org/web/20141128231625/http://www.mirror.co.uk/news/uk-news/deadly-spider-can-kill-one-4715326|url-status=live}}</ref> Two females were discovered in the Iranian port city of [[Bandar Abbas]] in 2010.<ref>{{cite journal|author1=Shahi, M. |author2=Hosseini, A. |author3=Shemshad, K. |author4=Rafinejad, J. |year=2011|title=The Occurrence of Red-Back Spider Latrodectus hasselti (Araneae: Theridiidae) in Bandar Abbas, Southern Part of Iran|journal= Journal of Arthropod-Borne Diseases |volume=5|issue=1|pages=63–68|pmid=22808411 |pmc=3385565 |url=http://journals.tums.ac.ir/full_text.aspx?org_id=59&culture_var=en&journal_id=20&issue_id=2289&manuscript_id=18843&segment=en|archive-url=https://web.archive.org/web/20131019130429/http://journals.tums.ac.ir/full_text.aspx?org_id=59&culture_var=en&journal_id=20&issue_id=2289&manuscript_id=18843&segment=en|archive-date=19 October 2013 }}</ref>

There is an established population of redback spiders in [[Osaka]], Japan,<ref name="distributions paper"/><ref>{{cite journal|last=Ori|first=Masahisa|author2=Shinkai, Eiichi|author3=Ikeda, Hiroyoshi|title=Introduction of Widow Spiders into Japan|journal=Medical Entomology and Zoology|year=1996|volume=47|issue=2|pages=111–19|language=ja|doi=10.7601/mez.47.111|doi-access=free}}</ref><ref name=nihei>{{Cite journal | last1 = Nihei | first1 = N. | last2 = Yoshida | first2 = M. | last3 = Kaneta | first3 = H. | last4 = Shimamura | first4 = R. | last5 = Kobayashi | first5 = M. | title = Analysis on the Dispersal Pattern of Newly Introduced ''Latrodectus hasseltii'' (Araneae: Theridiadae) in Japan by Spider Diagram | doi = 10.1603/0022-2585-41.3.269 | journal = Journal of Medical Entomology | volume = 41 | issue = 3 | pages = 269–76 | year = 2004 | pmid =  15185925| s2cid = 6939079 | doi-access = free }}</ref> thought to have arrived in cargoes of wood chips.<ref name="Vic">{{cite web | author= Victoria Museum | title= Redback Spider | url= http://www.museum.vic.gov.au/spidersparlour/spider13.htm | access-date= 18 February 2007 | archive-date= 27 January 2007 | archive-url= https://web.archive.org/web/20070127012926/http://www.museum.vic.gov.au/spidersparlour/spider13.htm | url-status= live }}</ref>
In 2008, redback spiders were found in [[Fukuoka]], Japan. Over 700 have been found near the container terminal in [[Hakata Bay]], Fukuoka City.<ref name="xinhuanet1">{{cite web |url=http://news.xinhuanet.com/english/health/2012-12/26/c_132065195.htm |title=Japan's Fukuoka Wipes Out over 4,600 Poisonous Red-back Spiders |website=News.xinhuanet.com |date=26 December 2012 |access-date=4 September 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130925195744/http://news.xinhuanet.com/english/health/2012-12/26/c_132065195.htm |archive-date=25 September 2013  }}</ref> Dispersal mechanisms within Japan are unclear, but redbacks are thought to have spread by walking or by being carried on vehicles.<ref name=nihei/> In September 2012, after being bitten a woman was hospitalised in the Higashi Ward of Fukuoka City.<ref name="FukuokaNow">{{cite web | work= Fukuoka Now | title= Woman Bitten by Deadly Redback Spider | url= http://fukuoka-now.com/news/woman-bitten-by-deadly-redback-spider/ | access-date= 6 September 2012 | archive-date= 9 September 2012 | archive-url= https://web.archive.org/web/20120909181756/http://fukuoka-now.com/news/woman-bitten-by-deadly-redback-spider/ | url-status= live }}</ref> Signs warning about redback spiders have been posted in parks around the city.<ref name="xinhuanet1"/>