Lampona

Physical description and identification

Lampona is the largest and best known genus in the family Lamponidae, a group of flat-bodied nocturnal hunters confined almost entirely to Australia and its neighbours. Around sixty species have been described, most in Norman Platnick's 2000 revision of the family for the American Museum of Natural History.

Two points of confusion first. The figure of "57 species in the Lamponidae family" counts Lampona, not the family; Lamponidae is far larger, with around two dozen genera and roughly two hundred species. And these are not grassland spiders — every species in the genus is a crevice dweller found under bark, stones and litter.

Adults

• Size: from small bushland species of 5–8 mm up to the house species, in which females reach about 18 mm and males 12 mm, with a leg span near 28 mm.
• Shape: an elongated, near-cylindrical abdomen on a low, flattened carapace — a build made for sliding into narrow gaps. The legs are short, strong and held close to the body.
• Colour: dark grey to black-brown bodies with lighter orange-brown legs, often faintly banded. Many species carry pale abdominal markings; in L. cylindrata and L. murina it is one crisp white spot at the very tip, which gives the white-tailed spiders their name. Most other members of the genus lack it.
• Eyes: eight small eyes of similar size in two short rows on a low face, none enlarged. See our guide to spider eyes.
• Species identification: not possible from a photograph. Lampona are separated on the adult male palp and female epigyne under a microscope, so even the two house species cannot be told apart by eye.

Eggs and egg sacs

Females lay their eggs — around 80 to 100 in the larger species — in a flattened, disc-shaped white silk sac tucked into a crevice under bark, beneath a rock or inside a roof cavity. She stays with the sac until the young emerge, and may build more than one in a season.

Spiderlings

Hatchlings are pale with dark markings and leave the sac on foot after their first moult. Ballooning has not been shown for the genus, and the claim that the young drift away on air currents does not fit these heavy, flat-bodied walkers — see spider ballooning for the families that do. Juveniles hunt small spiders early and take a year or more to mature.

The hunt, not the web

No Lampona builds a capture web. Silk goes into the egg sac, draglines and a flimsy temporary retreat where the spider lies up by day. The genus is strongly araneophagic, and its signature tactic is to enter another spider's web after dark, approach the resident along the silk, and strike first. The staple prey is the black house spider; also on the list are the grey house spider, cellar spiders, curtain-web spiders and juvenile redbacks.

Where Lampona spiders live

The genus is Australasian. Its centre of diversity is Australia, with species in every state and in habitats from Tasmanian wet forest to central desert, and a handful extend to New Guinea — Lampona papua is named for that. Two species crossed the Tasman: white-tailed spiders are now established in New Zealand after arriving in freight.

Within Australia the two familiar species split the continent in half. Lampona cylindrata holds the south — South Australia, Victoria, Tasmania, southern New South Wales and south-west Western Australia — while Lampona murina runs up the east coast around Sydney and Brisbane. The other fifty-odd species are bushland animals, many with very restricted ranges.

The habitat requirement is constant: a flat, dark gap — loose bark, logs, rock crevices, litter and mulch in the bush; wall cavities, stored boxes and outdoor furniture around a house. Only the two synanthropic species follow their prey indoors.

Are Lampona spiders venomous?

Yes, they have venom, and they use it on other spiders. For people, no Lampona species is medically significant, and no antivenom exists or is required.

That deserves saying plainly, because of the reputation the genus carries. From the 1980s onward, white-tailed spiders were blamed in Australia and New Zealand for severe necrotic skin ulcers, on evidence that was always thin: case reports in which the spider was rarely caught and almost never identified by an expert. The claim was tested by Geoffrey Isbister and Michael Gray in a prospective study published in 2003, covering 130 definite Lampona bites with the spider identified in every case. None of the 130 produced necrosis or an ulcer.

The ulcers once attributed to this genus are now put down to bacterial infection, vascular and diabetic ulcers, pyoderma gangrenosum and misdiagnosed skin cancers. Treating an unexplained ulcer as a spider bite delays the correct diagnosis. Australia's dangerous spiders, the funnel-webs and the redback, are unrelated to Lampona — see the most venomous spiders.

Can Lampona spiders bite?

They can. Because the two common species wander indoors at night, they are among the more frequently recorded biters in southern Australia — not from aggression, but because they end up in shoes, towels and bedding, and a spider pressed against skin defends itself.

The usual bite produces immediate sharp or burning pain, a red mark or small weal, swelling and itching that can persist a few days. Pain eases within minutes to a few hours. Roughly a quarter of verified cases involved mild general symptoms — headache, nausea or malaise — that settled on their own.

First aid: wash the site with soap and water, apply a cold pack, take a painkiller if needed, and keep the area clean without scratching it. The realistic complication is secondary bacterial infection, not venom. Seek medical attention if pain is severe or spreading, if the site becomes hot and swollen after a day or two, if you develop a fever, or if there are signs of allergy. Pressure-immobilisation bandaging is for funnel-web and snake bites, not for this.

Ecological importance and behaviour of Lampona spiders

The defining behaviour of the genus is spider-hunting. Lampona are nocturnal, solitary and nomadic, with no territory beyond the crevice they rest in. They patrol bark, walls, fences and litter, and when they find an occupied web they go in — a high-risk move managed by testing the silk slowly and biting first.

Ecological role: they sit above most of the spider fauna around a building. A healthy Lampona population reduces Desidae webs on eaves and window frames; removing them increases the spiders in a house rather than reducing them.

Natural predators: birds, geckos and skinks, centipedes, scorpions, spider-hunting wasps and larger spiders such as huntsmen — see what eats spiders.

Season and lifespan: adults occur year-round in mild areas, peaking in summer and early autumn when males wander and indoor encounters spike. Lifespan is roughly one to two years; the figure of up to twenty years in popular accounts belongs to female tarantulas, not to a 15-millimetre hunting spider.

Living alongside them: shake out clothing left on the floor, keep beds clear of the ground, move woodpiles away from walls, and knock down the house-spider webs that draw them in. Residual sprays do little against a nomad.

Species in the genus and similar spiders

Quick facts

Did you know?

• The name Lampona comes from the Greek root meaning "to shine", for the bright pale spot at the abdomen tip — not, as is sometimes claimed, from a Middle English word for a lamp.
• Only a small minority of the roughly sixty Lampona are "white-tailed spiders"; most bushland members of the genus lack the clean tail spot entirely.
• Platnick's 2000 revision described dozens of new Lampona at once, many named after the localities where they were collected — Kapalga, Dwellingup, Moorilyanna, Talbingo.
• A Lampona will invade a redback's web to take a juvenile — hunting one of the continent's most venomous spiders on its home ground.
• The genus carries one of arachnology's most thoroughly debunked myths, and the myth is still winning: decades after 130 verified bites produced zero ulcers, "white-tail bite" is still offered as a diagnosis.

In summary, Lampona is a large Australasian genus of flat-bodied nocturnal spider-hunters, of which just two species meet people. They are venomous to other spiders and harmless to us, they build no web, and they earn their keep eating the house spiders on your walls.