A white-tailed spider feeding on its spider prey. Photo: © R Jackson
There are many species of white-tailed spiders and they are found throughout Australia. Some species are common in urban areas and are often seen in houses. White-tailed spiders usually wander at night, hunting and eating other spiders. The two common species, the Southern and Eastern White-tailed Spiders, Lampona cylindrata and L. murina, are similar in appearance and have overlapping distributions in the south-eastern Australia. Their bites have been controversially and often incorrectly implicated in causing ulceration in humans.
White-tailed spiders are vagrant hunters that live beneath bark, rocks, and in leaf litter and logs, in bushland and gardens, and they are often seen in houses. Tufts of specialised scopulate hairs on the ends of their legs allow them to walk easily on smooth or sloping surfaces. They make temporary silk retreats and spin disc-shaped egg sacs, each containing up to 90 eggs.
They are most active at night when they wander about hunting for other spiders, their preferred food. They have been recorded eating curtain-web spiders (Dipluridae), daddy-long-legs spiders (Pholcidae), Redback Spiders (Theridiidae) and Black House Spiders (Desidae). During summer and autumn white-tailed spiders are often seen in and around houses where they find both sheltered nooks and crannies and plenty of their favoured Black House Spider prey.
Where white-tailed spiders live
Forty species of white-tailed spiders have been described. They are found all over Australia and have been introduced into New Zealand. The two most common species live in southern and eastern Australia.
Map of Australia and New Zealand showing movement of the Southern and Eastern White-tailed Spiders, Lampona murina
and L. cylindrata
from Australia to New Zealand.
Are they dangerous?
Fiddleback Spider (Loxoceles rufescens). Photo: G Millen © Australian Museum.
Black house spider (Badumna insignis). Photo: M Gray © Australian Museum.
White-tailed spider bites can cause initial burning pain followed by swelling and itchiness at the bitten area. Occasionally, skin weals and local blistering or ulceration have been reported - conditions known medically as necrotising arachnidism. As well as the spider's venom, secondary bacterial infection of the wound could be a contributory factor in some bites.
Other spiders have also been reported to be involved in cases of minor skin ulceration. They include the Brown House Spider Steatoda; the Black House Spider, Badumna insignis; the Slender Sac Spider, Cheiracanthium; and the introduced Fiddleback Spider, Loxosceles rufescens.
However, a debate continues about the involvement of white-tailed spider bite in cases of ulcerative skin lesions. Although patients with such symptoms are often diagnosed as probable white-tailed spider bite victims, typically there is no definite evidence of a spider bite being involved. Sensational media reporting of supposed cases of severe 'necrotising arachnidism' has given white-tailed spiders a bad reputation.
Against this often anecdotal evidence, a recent study has monitored the medical outcomes of more than 100 verified white-tailed spider bites and found not a single case of ulceration (confirming the results of an earlier study). The available evidence suggests that skin ulceration is a rare rather than a common outcome of white-tailed spider bite.
There are a number of well-documented causes of severe inflammatory skin lesions and ulceration, notably bacterial and fungal infections. Such secondary (or primary) infections may be the cause of ulcerative symptoms that have been attributed to white-tailed spider bites.