Of around 650 species of spider in the UK, as few as a dozen are capable of delivering a bite to humans. In fact, in the five decades that I have spent poking around undergrowth and quiet corners, I hadn't not experienced a single nip. Then, as is often the way of things, I received two spider bites in two weeks last summer.
The first occurred in the garden from a species called Neriene peltata, a small, widespread arachnid with brown legs and distinct pale markings on the abdomen. It was not much bigger than the red ant I had presumed to find biting my thigh, and the pain was similarly mild and short-lived.
The second bite came while I slept. Or, more specifically, as I turned over in my sleep. This time, the culprit was Steatoda nobilis, commonly known as a noble false widow, which I could identify despite having unintentionally squashed it against the mattress.
The pain was sharper, more like a wasp or bee, and endured similarly, the zing lasting for several hours before subsiding into itchiness. In truth, I felt worse having killed the spider than I did from its bite, although my experience was mild compared to some.
Steatoda nobilis is one of six species of ‘false widow’ spiders in the UK, a half dozen that includes the rabbit-hutch spider (Steatoda bipunctata) and cupboard spider (Steatoda grossa) which are indigenous and reasonably widespread.
Native to Madeira and The Canary Islands, the noble false widow was first noted in Torbay, England, in 1879, with specimens believed to have been stowaways among imported bananas.
For more than a century, they remained localised around a few southern ports, but recent mild winters have seen a rapid expansion inland and north as far as Scotland.
This rapid expansion has occurred elsewhere in the world, with the species now established across mainland Europe, with pockets through the Americas and even a colony in New Zealand.
Nobilis is paler in appearance than other Steatoda species in the UK, with bronze-brown legs and a cream skull-shaped patterning on a body that measures up to 14mm long. Females are larger than males but rarely engage in post-mating cannibalism that is common among the Latrodectus genus of widow spiders.
They tend towards elevated positions, such as roof joints in outbuildings or gaps in masonry, where they construct an irregularly shaped web of dense, sticky silk. Woodlice are a common prey item, but nobilis is unfussy. One web I found was full of bumblebee remains, the spider exploiting a position close to a nearby nest.
Noble false widows detect prey through vibration and have poor eyesight, which is one reason why incidents occur such as my own where a spider is accidentally squashed and bites in self-defence. The venom can cause steatodism, a series of symptoms that include intense pain and fever. On occasion, these can escalate or the bite may develop a bacterial infection, whereupon hospital treatment should be sought.
False widow spiders can be respected rather than feared, however. We share our cottage with nobilis and grossa, both of which show no aggression and can be handled, sometimes tucking up and ‘playing dead’. For the most part there is harmony, although I tend to check beneath the duvet before getting into bed.
Top image: Getty Images
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