White-tailed spider

Taxobox
name = White-tailed spider

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image_wdith = 250px
image_caption = Adult in a glass jar
image_width = 250px
regnum = Animalia
phylum = Arthropoda
classis = Arachnida
ordo = Araneida
subordo = Araneomorphae
familia = Lamponidae
genus = "Lampona"
species = "L. cylindrata" "L. murina"
binomial = "Lampona cylindrata"
binomial_authority = L. Koch, 1866
binomial2 = "Lampona murina"
binomial2_authority = L. Koch, 1873

The white-tailed spider, (common species are "Lampona cylindrata", "Lampona murina") are medium-sized spiders from southern and eastern Australia, so named because of the whitish tips at the end of their abdomens. They have been introduced to New Zealand where they are considered a household pest.

By comparison with other well-known Australian spiders, white-tailed spiders do not appear to be particularly numerous, but may be responsible for a disproportionately high number of spider-bites because of their habits. Unlike the black house spider and the redback which are often seen in or around dwellings in a web, the white-tailed spider wanders around and may be encountered unexpectedly. Of the 130 recently-monitored cases, several spiders had been picked up off the floor accidentally by short sighted persons thinking that they were something else. More than 60% of the victims had been bitten by spiders that had got into clothing, into folded towels and into beds. In several more cases they were in shoes.

Information on the white-tail species is limited as they are only found in Australia and New Zealand with only a limited number of researchers working in the field.

Taxonomy

Ludwig Carl Christian Koch described "Lampona cylindrata" in 1866 and "Lampona murina" in 1873. The genus name comes from the Latin "lampo" which means shine. The species name "cylindrata" refers to the cylindric body shape, while "murinus" means "mouse-gray" in Latin.cite web | last = Gray | first =Mike | title =Lampona cylindrata (Family Lamponidae) White-tailed Spider| publisher = Australian Government: The Department of the Environment, Water, Heritage and the Arts | date = | url = http://www.environment.gov.au/cgi-bin/species-bank/sbank-treatment.pl?id=69194| accessdate = 2008-06-14]

Description

The two common species of white tailed spider are "Lampona cylindrata" and "Lampona murina". They are both similar in appearance; "L. cylindrata" is slightly larger with females being up to 18 mm long while males are up to 12 mm in body length.cite journal |author=Platnick NI |title=A relimitation and revision of the Australasian ground spider family Lamponidae (Araneae: Gnaphosoidea) |journal=Bull Am Mus Nat Hist |volume=245 |issue= |pages=1–328 |year=2000 |pmid= |doi=10.1206/0003-0090(2000)245<0001:ARAROT>2.0.CO;2 |doilabel=10.1206/0003-0090(2000)2450001:ARAROT2.0.CO;2] The legs span approximately 28 mm in diameter. [cite web | last = | first = | title =Spiders in New Zealand| publisher = New Zealand National Poison Centre | date = 2008 | url = http://poisons.co.nz/fact.php?f=10&c=20| accessdate = 2008-02-10] The two species are not easily distinguished from one another without microscopic examination. They are slender spiders having dark reddish to grey, cigar-shaped body and dark orange-brown banded legs. The grey abdomen bears a distinct white spot at the tip justabove the spinnerets.cite web | last = | first = | title =White-tailed spiders | publisher = Australian Museum | date = 2003 | url = http://www.amonline.net.au/factsheets/white_tailed_spider.htm| accessdate = 2008-02-10] cite web | last = | first = | title =White-tailed spiders (Lampona cylindrata and Lampona murina)| publisher = Museum of New Zealand Te Papa Tongarewa | date = 2003 | url = http://www.tepapa.govt.nz/TePapa/English/CollectionsAndResearch/Collections/InsectsSpidersAndSimilar/Spiders/Spiders_Web/What/White-tailed.htm| accessdate = 2008-02-10]

The similarities have led people to think there is only a single white tail spider. It is possible that not all white tail species have been identified. The descriptor, "white tail", is applied to a variety of species of spiders for which a distal white mark on their abdomen is a distinctive feature; other markings disappear with moultings but the white tail remains to adulthood.

Distribution

Both species are native to Australia. "Lampona cylindrata" is present across south east Queensland, New South Wales, Victoria, South Australia, Tasmania and Western Australia while "Lampona murina" is found in eastern Australia from north-east Queensland to Victoria. The spider has been introduced in New Zealand with "Lampona murina" residing in the North Island for over a hundred years while "Lampona cylindrata" has become widespread throughout the South Island since 1980.

Habitat, behaviour

They live in gardens and houses, beneath bark and rocks, in leaf litter and are often found in the folds of clothes, towels and shoes. They do not build webs. They are able to walk on glass, due to specialized hairs on the end of their legs. Most active at night, they hunt for other spiders. Their favoured prey is the black house spider.cite book | last = Forster | first = Ray | coauthors = Forster, Lyn | authorlink = | title = Spiders Of New Zealand And Their Worlwide Kin | publisher = University Of Otago Press | location = Dunedin | date = 1999 | pages = 111-2 | doi = | isbn = 1-877133-79-5]

No evidence of necrotic bite

The bite of the white tail has been wrongly implicated in cases of arachnogenic necrosis. The misassociation stems from a paper presented at the International Society on Toxinology World Congress held in Brisbane in 1982. Both the white tail and the wolf spider were considered as candidates for "possibly" causing "suspected" spider bite necrosis, though it later turned that the recluse spider was the culprit in the reported cases from Brazil.

Following this initial report numerous other cases implicated the white tailed spider in causing necrotic ulcers. [cite journal |author=Gray M |title=A significant illness that was produced by the white-tailed spider, Lampona cylindrata |journal=Med J Aust |volume=151 |issue=2 |pages=114–6 |year=1989 |month=July |pmid=2739605 |doi= |url=] [cite journal |author=St George I, Forster L |title=Skin necrosis after white-tailed spider bite? |journal=N Z Med J |volume=104 |issue=912 |pages=207–8 |year=1991 |month=May |pmid=2052219 |doi= |url=] [ cite journal |author=Skinner MW, Butler CS |title=Necrotising arachnidism treated with hyperbaric oxygen |journal=Med J Aust |volume=162 |issue=7 |pages=372–3 |year=1995 |month=April |pmid=7715520 |doi= |url=] [ cite journal |author=Chan SW |title=Recurrent necrotising arachnidism |journal=Med J Aust |volume=169 |issue=11-12 |pages=642–3 |year=1998 |pmid=9887918 |doi= |url=http://www.mja.com.au/public/issues/xmas98/chan/chan.html] All of these cases lacked a positively identified spider—or even a lack of a spider bite in some cases. Additionally there had not been a case of arachnogenic necrosis reported in the two hundred years of European colonisation before these cases.Dr Geoffrey Isbister from the University of Newcastle in Australia performed a study monitoring 130 cases of arachnologist identified white tailed spider bites, the study reported no incidents of necrosis, leading researchers to believe that such cases are a extremely rare outcome for a white-tailed spider bite.cite journal |author=Isbister GK, Gray MR |title=White-tail spider bite: a prospective study of 130 definite bites by Lampona species |journal=Med. J. Aust. |volume=179 |issue=4 |pages=199–202 |year=2003 |pmid=12914510 |doi=
url=http://www.mja.com.au/public/issues/179_04_180803/isb10785_fm.html] The major effects from a bite were local pain, a red mark, local swelling, and itchiness, rarely systemic effects of nausea, vomiting, malaise, or headache occurred.

Footnotes

References

* [http://www.austmus.gov.au/factsheets/white_tailed_spider.htm Australian Museum Online: White-tailed spider]
* [http://www.museum.vic.gov.au/spiders/detail.aspx?id=20&pic=0 Museum Victoria: White-tailed spider]
* [http://amonline.net.au/spiders/dangerous/white_tailed/index.htm Australian Museum Online: White-tailed spider - detail]
* [http://www.mja.com.au/public/issues/179_04_180803/whi10399_fm-2.html White, Julian, Department of Toxinology, Women's and Children's Hospital, North Adelaide, South Australia, "Debunking spider bite myths"]