White-tailed spider

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 red back 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.

Description, habitat, behaviour
The eastern and southern species are the most common species. They are similar in shape and colour and this has 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. White-tailed spider females are up to 18 mm long, males up to 12 mm. They live in gardens and houses, beneath bark and rocks, in leaf litter and so on. 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.

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.

Despite a lack of positively identified spiders—or even a lack of spider bites in some case—and also despite a dearth of cases of arachnogenic necrosis reported in the two hundred years of European colonisation, the white tailed was repeatedly blamed. A study published in 2003 monitoring 130 cases had no such incidents, leading researchers to believe that such cases are a rare—rather than a common—outcome for a white-tailed spider bite.

Names
The species name cylindrata refers to the cylindric body shape, while murinus means "mouse-gray" in Latin.