Resources
Reliable information about false widow spiders can sometimes be difficult to separate from exaggerated claims and anecdotal reports. The resources below bring together scientific research, university publications and specialist sources used to support information across this website, with a particular focus on the noble false widow (Steatoda nobilis) in Ireland and the UK.
Where possible, links are provided to the original peer-reviewed research or to the institution responsible for it.
Scientific research on false widow spiders
2026
Noble false widows in Irish urban habitats
A major Irish field study surveyed spiders across six urban centres over 11 months to examine the abundance and distribution of the noble false widow and other spiders living around buildings. Researchers found Steatoda nobilis to be one of the dominant spiders in the habitats surveyed and recorded established populations in Mayo and Sligo, where the species had not previously been recorded.
The research also examined seasonal patterns, prey availability and weather, providing one of the most detailed recent pictures of the species in urban Ireland.
Collier, B.L., Leonard, D., Lyons, K., Dunbar, J.P., Lawton, C. & Dugon, M.M. (2026). Survey of Synanthropic Spiders in Ireland Reveals Expansion and Dominance of the Invasive Noble False Widow Steatoda nobilis in Urban Habitats (Araneae: Theridiidae). Ecology and Evolution, 16, e73193.
University of Galway research record →
2017
Distribution and identification of the noble false widow in Ireland
This Irish study investigated the distribution, preferred habitats and reproductive rate of Steatoda nobilis. It also documented variations in the spider’s appearance to help improve identification.
At the time of the research, the species had been recorded from at least 16 Irish counties and was particularly widespread around buildings and street furniture in the greater Dublin area.
Dugon, M.M., Dunbar, J.P., Afoullouss, S. et al. (2017). Occurrence, reproductive rate and identification of the non-native Noble false widow spider Steatoda nobilis (Thorell, 1875) in Ireland. Biology and Environment: Proceedings of the Royal Irish Academy, 117B(2), 77–89.
University of Galway research record →
2020
What is in noble false-widow venom?
Researchers from NUI Galway and the University of Liège analysed the venom of Steatoda nobilis using genetic and protein-based techniques. They found a substantial number of toxins related to those occurring in true widow spiders of the genus Latrodectus, including latrotoxins.
This research helps explain some of the biological effects associated with noble false-widow venom. Similarities in venom composition do not, however, mean that noble false widows present the same danger to humans as black widow spiders. Clinical risk depends on much more than the presence of related toxins.
Dunbar, J.P., Fort, A., Redureau, D., Sulpice, R., Dugon, M.M. & Quinton, L. (2020). Venomics Approach Reveals a High Proportion of Latrodectus-Like Toxins in the Venom of the Noble False Widow Spider Steatoda nobilis. Toxins, 12(6), 402.
University of Galway summary →
Bacteria associated with false widows and other house spiders
Researchers examined bacteria found on Steatoda nobilis and two other spiders commonly associated with buildings. A number of bacterial species with potential medical relevance were recovered from the spiders’ body surfaces and mouthparts, and some isolates showed resistance to one or more antibiotics.
The study showed that bacterial transmission during a spider bite is biologically plausible, but it did not establish that false-widow bites routinely transmit bacterial infections. Infection following any suspected bite can have several possible causes, and the relationship remains an area requiring further research.
Dunbar, J.P., Khan, N.A., Abberton, C.L. et al. (2020). Synanthropic spiders, including the global invasive noble false widow Steatoda nobilis, are reservoirs for medically important and antibiotic resistant bacteria. Scientific Reports, 10, 20916.
False widow bites and medical research
2022
Confirmed noble false-widow bite cases
Many injuries described as “spider bites” are never linked to an identified spider. This case series is particularly useful because the researchers restricted their analysis to cases where the identity of Steatoda nobilis could be supported, including cases confirmed through photographs, specimens or genetic analysis.
The study reported 16 new envenomation cases and documented effects ranging from pain, swelling and other local symptoms to less-common systemic symptoms. Some patients required hospital treatment. More significant reactions were documented within the case series, but these should not be interpreted as the typical outcome of every noble false-widow bite.
Dunbar, J.P., Vitkauskaite, A., O’Keeffe, D.T., Fort, A., Sulpice, R. & Dugon, M.M. (2022). Bites by the noble false widow spider Steatoda nobilis can induce Latrodectus-like symptoms and vector-borne bacterial infections with implications for public health: a case series. Clinical Toxicology, 60(1), 59–70.
For practical information about symptoms, what to do after a suspected bite and when to seek medical advice, see our false widow spider bite guide.
National Poisons Information Centre of Ireland
The National Poisons Information Centre, based at Beaumont Hospital in Dublin, provides specialist poisons information in Ireland and maintains official contact information for members of the public and healthcare professionals.
For current contact details and poisons information, visit the official National Poisons Information Centre website.
National Poisons Information Centre →
Spider identification and records
National Biodiversity Data Centre
The National Biodiversity Data Centre maintains Irish biological records and distribution maps for thousands of species, including the noble false widow, Steatoda nobilis.
Its Biodiversity Maps service can be used to explore recorded Irish distribution, while Ireland’s Citizen Science Portal allows members of the public to submit wildlife observations for inclusion in national recording datasets.
View Irish records for Steatoda nobilis →
Natural History Museum
The Natural History Museum provides a useful illustrated guide to identifying false widow spiders and distinguishing between the principal species found in Britain and Ireland.
Its identification material covers the noble false widow (Steatoda nobilis), cupboard spider (Steatoda grossa) and rabbit hutch spider (Steatoda bipunctata), including differences in size, markings, habitat and appearance.
Spider season in Ireland and why you’re seeing more spiders this September
Why do we see more spiders in September? For some of the spiders we commonly find around Irish homes, autumn is an important time for mating. Mature males may leave their usual web or hiding place and start wandering in search of females. This makes them much more...
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...
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...
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...
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...