The 'False Widow' spider is spreading through
Southern England – this is a female Steatoda nobilis
(Image: Wikimedia Creative Commons)
London-based urban gardener, Dan Combes, tells us of his close encounter of the eight-legged kind...
Introducing the False Widow! Britain's deadly spider... or is it?
Recently both London and National media has been littered with articles documenting the rapid rise of the False Widow, labelling it "Britain's most deadly spider."
The Daily Star reports '...a plague of 10 million False Widow spiders.' Both The Independent and The Guardian discuss the potentially lethal bite of this small yet dangerous looking arachnid.
As a London gardener the only bite or sting I am likely to endure is that of a nettle or a wasp. Has this all changed?
Meeting the False Widow
Steatoda nobilis male (Image: Wikimedia
Last week I was building a green roof on a newly built kitchen extension. This is a great option for Londoners with limited space, but a thirst for greenery. It is amazing what you can successfully grow in a properly irrigated yet thin soil medium.
As I was unravelling a roll of permeable membrane a small spider scuttled over my hand. A distinctive cream band around the front of its abdomen and its reddish legs caught my attention. Research confirmed that I was dealing with a False Widow.
The False Widow (Steatoda nobilis), named due to its rather tenuous resemblance to the far more dangerous Black Widow, was first discovered in England in Plymouth.
Steatoda nobilis in its web (Image: Dan Combes)
Native to Madeira and the Canary islands it is thought to have hitched a ride on a banana boat, joining a long lineage of exotic species that have made their way to these shores as a result of our love for those fruits.
For 100 years Steatoda nobilis was content to languish in the milder climate of the south coast. Milder winters (attributed to climate change) have enabled the population to move inland, with hosts of sightings now reported in London.
Nobody really cared when a few Cornish pensioners reported swelling and nausea as a result of False Widow bites.
But when Londoners started reporting False Widow sightings, the media got excited.
Just how deadly is the False Widow?
Another female False Widow scuttles
through the grass
(Image: Dan Combes)
There have been exactly zero recorded deaths. The Natural History Museum describes the effects of biting as follows:
"...reports from those bitten describe a certain amount of pain... and often a degree of swelling in the affected part. Some describe fever and a general feeling of being unwell... more serious symptoms have been reported but are likely to be exceptional reactions of individuals to the venom."
The False Widow is not going to kill you. For the majority of us a bite will resemble nothing more than a wasp sting.
My limited understanding of behavioural ecology reminds me that the production of venom is very energy intensive. Spiders don't scuttle around squirting venom willy nilly. It is used as a last form of defence.
As the temperature drops Steatoda nobilis will start making its way indoors. If you awaken to screams of, "Help! There's a spider in my bed!" just grab a piece of card and a glass, scoop it up and throw it out the window.
If you've encountered the False Widow, let us know your story below!
Flowers for a green roof
Lavender is a great urban green roof plant – it's perfect for city bees, easy to keep under control, and provides the most heavenly scent.
Or any of a number of spring bulbs can be naturalised into shallow soils – providing flushes of colour and important early food for pollinators. They're largely fit and forget too, with a single planting lasting 5 years or more. Consider any of Narcissus, Crocus, Bluebell, Grape hyacinth, Snake's head fritillary, Tulips or Wood anemones.