The false widow spider is now widespread throughout Ireland.
And they’re here to stay!
Originally from Macaronesia, including Madeira and the Canary Islands, the noble false widow has become established in Ireland and several other parts of Western Europe.
What is a false widow spider?
The name “false widow” applies to several different species of spider that bear a resemblance to the true black widows. Three false widow species are found in Ireland, with the noble false widow being the most commonly encountered
False widow spiders belong to the genus Steatoda and are part of the same spider family as the true widow spiders (Latrodectus), which include the infamous black widow. This relationship helps explain some of their similarities. Both have relatively slender legs, rounded or bulbous abdomens and build irregular, tangled webs rather than the familiar circular webs seen in gardens.
The name “false widow” comes from their resemblance to true widow spiders, but there are important differences between the two. Although research has found similarities between some components of their venom, false widow bites generally produce much less severe effects in people than bites from medically significant black widow species.
Three Steatoda species have been recorded in Ireland: the noble false widow (Steatoda nobilis), the cupboard spider (Steatoda grossa) and the rabbit hutch spider (Steatoda bipunctata).
When people in Ireland or the UK talk about a “false widow”, they are usually referring to the noble false widow, Steatoda nobilis. It is the best-known and most widespread of the false widows encountered around urban areas and is the species responsible for much of the public and media attention surrounding false widow spiders.
False widow spider fun facts
False widow species commonly found in Ireland
Years maximum recorded lifespan
Potential offspring in a year
%
Of confirmed bites involved beds/resting or clothing
Statistics refer primarily to research on the noble false widow (Steatoda nobilis).
Gathered from data recently published by the Venom Systems Laboratories at NUI Galway.
The noble false widow spider
While not as infamous as the black widow, the noble false widow spider is by far the most notorious of the false widow species and accounts for the majority of recorded bites.
Noble false widow
Steatoda nobilis
Noble false widows in Ireland
The noble false widow (Steatoda nobilis) is the best-known of Ireland’s three false widow species and the one most commonly associated with reports of false widows around Irish homes and buildings.
Originally native to Macaronesia, the species was recorded in southern Britain in the late 19th century. In Ireland, it was first reported in Bray, Co. Wicklow, in the late 1990s and has since become well established, particularly in urban areas.
Noble false widows are strongly associated with buildings and other sheltered structures, where they construct irregular tangle webs around window frames, walls, sheds, garages and similar undisturbed locations.
Although the noble false widow is capable of biting and its venom can produce medically significant symptoms in some cases, bites are uncommon. The spider is not aggressive towards people and will generally remain in or close to its web unless disturbed.
The spider genus Steatoda, in the family Theridiidae, includes about 120 recognised species distributed around the world. Three of these false widow species can be found in Ireland and the UK.
False widows are just a few of the hundreds of spider species found in Ireland. Explore our guide to spiders in Ireland to identify some of the species most commonly encountered in Irish homes and gardens.
False widow spider species in Ireland
The three most common false widow spiders in Ireland and Britain are Steatoda nobilis, Steatoda grossa, and Steatoda bipunctata.
Noble false widow spider
Steatoda nobilis
Cupboard spider
Steatoda grossa
Rabbit hutch spider
Steatoda bipunctata
What does a false widow look like?
The noble false widow is typically dark brown with variable cream markings on the abdomen, sometimes forming a pattern that has been compared to a skull or leaf. However, these markings can be faint or incomplete and should not be relied upon alone for identification.
The cupboard spider (Steatoda grossa) is often darker and more uniformly coloured, particularly as females mature, while the smaller rabbit hutch spider (Steatoda bipunctata) usually has a different pattern and body shape.
Males are generally smaller and more slender than females, with proportionally longer legs. Juveniles can also look quite different from mature adults.
A spider’s web and location can provide valuable additional clues. False widows construct irregular three-dimensional tangle webs rather than the circular orb webs commonly seen in gardens.
Where you will likely find them
Around homes and other buildings, webs may be found around window and door frames, sheds, garages, conservatories, wall crevices, roof spaces and other protected corners. Outdoor structures such as fences, railings and garden furniture can also provide suitable locations.
False widows generally remain in or close to their webs, often retreating into a crack or crevice during the day and becoming more active after dark.
Finding a tangled web around a building does not automatically mean that a false widow is present. Several other Irish spiders construct superficially similar webs, so the spider itself should also be examined before attempting an identification.
Living with false widow spiders
If false widows or other spiders are regularly finding their way indoors, our practical guide to keeping spiders out of your home covers simple ways to reduce entry points and make problem areas less attractive to spiders. Avoid handling a suspected false widow with bare hands. If you need to move one, use a suitable container or spider catcher and release it in a sheltered location away from frequently used areas.
For anyone concerned about a suspected bite, our false widow spider bite guide explains the symptoms reported in Ireland, what to do following a bite and when medical advice may be appropriate.
“The False widow spider is a new addition to Irish ecosystems and it is here to stay. It is therefore important to learn about its ecology and the potential risks associated with its bite.”
The false widow spider is not aggressive and will usually only bite a person when it feels threatened.
“Although our study shows that the venom of false widow spiders may be more potent than previously thought, it does not mean we need to fear them. In many parts of the world even “true” black widow bites rarely require medical attention.“
“Some 23 years after being first spotted in Ireland, the Noble false widow is now established in almost every county on the island. In east coastal counties such as Dublin, they are one of the most common urban spiders.”
Why you may notice more false widow spiders around your home in Autumn
Seasonal activity and mating behaviour can make false widow spiders more conspicuous at this time of year, particularly around buildings.
Finding more spiders around your home in Autumn doesn’t necessarily mean you have an infestation. Spiders may be noticed in different parts of a building as they move around or use sheltered places for webs. If you’d prefer to see fewer of them indoors, there are simple steps you can take to reduce the chances of spiders finding their way into your home.
See our practical guide to keeping spiders out of your house throughout the year.
False widow spider in Ireland stories
Cupboard spiders get a gentle hooshing
Look what I found cleaning out my bird seed storage a while back… One of the False Widow species… A first for me! The cupboard spider – Steatoda grossa. About 3 or 4 of them. Was surprised to find so many large spiders tolerating each other in the small confines of a garden seat box used to store bird feed.
Met my first false widow today!
This morning, a fresh sunny day in April in coastal Galway, just as we were getting the kids ready to leave for school, a false widow spider started making its way from the front door across our hallway. It wasn't moving too quickly so I was able to get an envelope to put under it and then take it outside. Once outside, I immediately noticed it shot...
False widow spider in my pajamas!
A Close Encounter in Cork Hey there! Hope you're keeping well, I actually stumbled across my first false widow spider earlier today and identified it with the help of the internet. I have nothing but good things to say about it honestly! I typically tend to keep my pajamas on if I know I'm not going out for the day, so I had them on for quite a while. I...
False widow spider in my house
Over the past year I have noticed a lot of false widow spider webs in my back garden around my shed. I recognised them due to their messy box/sail like shape - as opposed to the traditional neat patterned web of a typical garden spider. The spiders are only active at night so I wasn't too concerned. But I was very surprised by how many of their webs...
Baby false widow spider bite?
Was it a baby false widow spider bite? I'm pretty sure I sustained a baby false widow spider bite this summer but I'm not 100% sure. I have seen loads of the adults recently, really for the first time too. A neighbour told me last year that they had a lot of false widow spiders in their back garden. That year I started to notice a few around the outside...