A white-tailed spider bite is painful, but it is not the flesh-eating injury many people fear. A study published in the Medical Journal of Australia followed 130 people who were bitten by a white-tailed spider that was caught and identified by an expert. None of them developed a necrotic ulcer. Most had pain and a red mark that faded within a day or so. The real question for most Shire homes is why these spiders keep coming inside.
How do you identify a white-tailed spider?
The Australian Museum describes a spider with a long, cigar-shaped body that is dark reddish to grey, and dark orange-brown banded legs. The grey abdomen has two pairs of faint white spots and a clearer white spot at the tip, which gives the spider its name. Two similar species, *Lampona cylindrata* and *Lampona murina*, both live in New South Wales.
White-tailed spiders do not build a web to catch food. They wander at night and shelter by day under bark and rocks, in leaf litter, logs and garden debris, and in gaps around the house. Tufts of fine hairs on their feet let them walk up smooth walls and across ceilings.
Why do white-tailed spiders come into the house?
They come in to hunt other spiders. The Australian Museum lists black house spiders, daddy long legs, redbacks and curtain-web spiders among their recorded prey. It also notes that in summer and autumn white-tailed spiders are often seen in and around houses, where they find sheltered nooks and plenty of black house spiders to eat. So a white-tailed spider indoors usually points to plenty of other spiders around the windows and eaves.
Loftus is a residential suburb with a bushland feel, sitting next to the Royal National Park. A Loftus family that keeps finding white-tailed spiders in the laundry and hallway through late summer, with black house spider webs around every window, should book spider control in Loftus that deals with both the hunters and the spiders they are hunting.
Sandy Point is a small pocket of three streets surrounded by national park bushland on the Georges River. A Sandy Point home with leaf litter and logs right up to the back steps gives white-tailed spiders shelter only metres from the door, so spider control in Sandy Point should cover the outside edge of the house as well as the rooms where the spiders are being seen.
What does a white-tailed spider bite actually do?
The study, by Geoffrey Isbister and Michael Gray, collected bites from February 1999 to April 2002 through emergency departments and poisons information centres. A case only counted if the spider was caught and identified to species.
Across those 130 bites:
- everyone had pain or discomfort, and it was severe in 27% of cases
- 83% had a red mark and 44% had itchiness, sometimes starting hours or days later
- 9% had effects beyond the bite site, most often nausea
- the effects lasted a median of 24 hours
- there were no necrotic ulcers and no confirmed infections
About a fifth had pain only, a third had pain and a red mark that went within 24 hours, and the rest had a painful or irritating red lump that lasted longer. Twelve people went to an emergency department and none was admitted.
Where did the flesh-eating reputation come from?
The Australian Museum puts it down to sensational media reports of skin ulcers that were blamed on white-tailed spiders, usually with no direct evidence that a spider had bitten the person. The study authors concluded that these bites are very unlikely to cause necrotic ulcers and that doctors should look for another cause.
So if a sore is getting bigger or will not heal, see a doctor rather than blaming a spider and waiting.
Where in the house do bites happen?
Almost always indoors and at night. In the study, 95% of bites happened inside, three quarters between 4 pm and 8 am, and the busiest time was between 8 pm and midnight. Nearly all were in the warmer months from September to April.
What people were doing at the time follows a clear pattern. About a third were in bed or asleep, a fifth had just got dressed, and others were bitten in or after a shower, or while drying off with a towel. In 63% of cases the spider was trapped between bed sheets, a towel or clothes left on the floor and the person's skin. It was not hunting people.
Grays Point sits beside the Royal National Park, overlooking the Port Hacking estuary. A Grays Point household where someone has been bitten in bed, and where white-tailed spiders keep appearing on the bedroom ceiling, has good reason to book quick spider control in Grays Point before the next bite rather than after it.
Why should spider control cover the other spiders too?
Because removing one white-tailed spider does nothing about the food that brought it inside. If black house spiders stay in the window frames and eaves, more white-tailed spiders will follow.
You do not need bushland behind the house for this to happen. A Caringbah brick home on a suburban street, with black house spider webs packed into the window corners and under the eaves, can still draw white-tailed spiders inside. When you book spider control in Caringbah, mention those webs so the technician checks where the prey spiders are living, not just where you saw the white-tailed one.
Before you book
Note these details so the technician can plan the visit:
- where in the house you have seen white-tailed spiders, and which rooms most often
- whether anyone has been bitten, and where they were at the time
- where other spider webs are building up, such as window frames, eaves, the garage or the pergola
- whether bush, leaf litter, logs or woodpiles sit close to the walls
Send those details to our team for pest control help in the Sutherland Shire: call Sutherland Shire Pest Control Pro on 02 8360 3033 or email [email protected].