Science | False widow, false alarm?
With Halloween just past, it’s apt for there to be a scare story about a genus of venomous spider that has started to make its presence felt. The bite of the false widow or steatoda nobilis has caused a 22-year old man to need emergency surgery and a 14-year old girl is still suffering the effects of the spider’s bite nine months after it happened.
The venom of the spiders can cause swelling, chest pain and numbness in victims. Sightings of false widows in a Gloucestershire school have caused it to be closed for a day to allow pest control to fumigate the premises. Several newspapers have run headline stories about the false widow: this is an issue that is being taken very seriously.
But is the fear of these spiders justified or the product of media scaremongering? The false widow is not aggressive unless provoked, and this is most likely to happen accidently such as when the spider is trapped in clothing or squashed. Nobody has died from a false widow bite; the schoolgirl and the young man were both unfortunate enough to suffer an extremely bad allergic reaction. To most people, the sensation of being bitten has been compared to anything from a nettle to a bee sting. Whilst this is undoubtedly painful, compared to bee and wasp stings (which do kill 10 or so people every year), incidences of spider bites are extremely rare. They tend to make the news due to their unusualness, and many people’s natural fear of spiders.
The false widow is not a new invader to these shores. It has been in the UK since the late 19th century, thought to have been imported along with a shipment of bananas from the Canary Islands. Until recently, it took up residence exclusively near the south coast of Devon and sightings were rare. Of late, the spider’s territory has spread north eastwards and sightings have been reported as far north as Birmingham. These movements are believed to have been facilitated by changes to the climate that have allowed it to thrive in southern and central England and the mild October weather that has caused the spiders to be more active this year. It’s quite possible that as they become more established in this country that they’ll be moving into a student flat near you. Just remember as you run away screaming in terror that you’re more likely to hurt yourself falling down the stairs.