Noble false widow spider marches north in the UK

Feb 23, 2012
Noble false widow spider, Steatoda nobilis. © Alvesgaspar, Creative Commons Attribution-Share Alike 3.0 Unported

The noble false widow spider, a species often mistaken for the black widow spider in the UK, is spreading north, Natural History Museum enquiry records show.

The noble false widow spider, Steatoda nobilis, is not native to the UK and was accidentally introduced more than 100 years ago from the Canary and Madeira islands, probably among crates of imported fruit.

It slowly established itself near the south coast, particularly in Dorset, Hampshire and Devon, and in the last 25 years has significantly increased its foothold in the UK. 

Sightings of the noble false widow spider continue to come from further afield, and it is likely that climate change, and the warmer winters this brings, has contributed to this spider's continued colonisation of the UK.

The Museum’s Identification and Advisory Service (IAS) and the Identification forum get many enquiries about these arachnids each year. IAS manager Stuart Hine explains, ‘Steatoda nobilis continues to colonise the southern counties and could turn up almost anywhere in southern and midland counties. 

"London records are increasing and I now have many living around the outside of my home near Reading."

Noble false widow spider

Like the spider, the noble false widow spider has a striking bulbous abdomen, but it is brownish in colour rather than pitch black, usually with distinctive cream markings and reddish-orangey legs. 

Noble false widow spider marches north in the UK
False widow spiders are often thought to be black widow spiders (above) © National Oceanic and Atmospheric Administration/Department of Commerce

They feed on a wide variety of insects and other invertebrates that become trapped in their 'tangle webs'. Females can grow to 15mm, or 32mm including the legs.

Noble false widow spiders are most commonly found in and around domestic and commercial premises and usually make their webs a good height off the ground on external walls of houses and outbuildings. 

Stuart says, "They appear to have a distinct preference for south facing walls and love conservatories and toilet blocks." 

Spider bites

Both Steatoda and Latrodectus are in the same family of spiders called Theridiidae, the comb-footed spiders. They make similar 'tangle' webs, shown here.

Many of the IAS enquiries are from people worried that a noble false widow spider may bite. It is probably the UK’s most venomous spider but bites are rare and usually result from handling the spider roughly or from a spider being trapped between clothing and skin. 

Bite symptoms are usually no more severe that a bee or wasp sting, but a handful of those who have been bitten have described more acute symptoms including throbbing pain, swelling and tingling in the fingers.

The IAS has received no more than 30 confirmed reports of noble false widow spider bites over a 16-year period. 

False widow spiders in the UK

Of the around 650 species of spiders in the UK, 6 belong to the false widow group, or genus, Steatoda. All except Steatoda nobilis are native. They were given their name because they look like the black widow spiders.

The 2 false widow spiders most often mistaken for black widows are Steatoda grossa, the one that most resembles a black widow, and Steatoda bipunctata, known as the rabbit hutch spider.

Black widow spiders

Black widow spiders, which have a scary reputation because the females sometimes kill the male after mating, belong to the Latrodectus genus. They have a nasty bite that is occasionally fatal to humans. 

Black widow spiders are found around the world, including North and South America, Australia and also southern Europe. Although individuals are occasionally imported with goods, they are unlikely to become established in the UK.

Explore further: Male monkey filmed caring for dying mate (w/ Video)

Provided by Natural History Museum

5 /5 (1 vote)
add to favorites email to friend print save as pdf

Related Stories

Male black widows look for well-fed mates

Jul 07, 2011

(PhysOrg.com) -- According to a new study published in Animal Behaviour, a male black widow spider is able to identify a female spider that has eaten well by simply taking a few steps on the web she spins. ...

Surviving sex with black widows

Aug 08, 2011

Scientists have discovered that male black widow spiders, famous for ending up as their mates' post-coital supper, are not as clueless as you might think. In a series of careful experiments, a team of researchers ...

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

Apr 18, 2014

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...