False Widows everywhere! RUN! … No, no Stop! I am only joking, however this is the view of a great many people around the UK and this is often fueled by the media. Spring is not far around the corner, which means it won’t be long before people start venturing outside again and so it won’t be long before “false widows” are back in the news. In this post, I hope to shed some light on this topic, and while I realise that this is not dissimilar to my last post but this is less of a personal opinion and just an annoyance at ignorance (I’ll just clarify that by saying, my annoyance isn’t with the public, I don’t expect everyone to know about spider venoms, but the media spread false “facts” that fuels this).
Once again, a bit of terminology needs to be cleared up, the term “false widow” actually refers to a whole genus of spiders from the family Theridiidae, the Steatoda genus. There are around 122 species of spider in the Steatoda genus, and around six are found in the UK, with most not being native. Steatoda nobilis, S. bipunctata and S. grossa are all found in the UK and are the three most commonly seen with the ‘noble false widow’ (S.nobilis) being the largest and most often spoken about. These spiders originate from a variety of locations and are found across a large proportion of the globe, S.bipunctata is known as a cosmopolitan species because it’s range spreads across much of the world, with the other two being more restricted but still found widely across Europe and often North Africa. In the UK they are found mainly in the South, however they are beginning to spread, which is thought to be due to the climate getting warmer and more suitable for them.
They get their name “false widows” because, in appearance, they resemble the notorious black widow of North America and the more dangerous Red-Backed Widow from Australia. Both these “true widows” and “false widows” belong to the family Theridiidae and therefore it makes sense that they share a number of characteristics such as their appearance, web design and behaviour. However, the “true widows” belong to the genus Laterodectus and possess the infamous Latrotoxin, which is a particular neurotoxin found in their venom and this is what makes them potentially deadly. Although, I’d like to point out that fatalities from these ‘deadly spiders’ are incredibly rare, especially since the anti-venom has been developed, and they’re also non-aggressive spiders that are reluctant to bite. I mean, why waste their energetically expensive venom on something that they can’t eat. Anyway, got side tracked with the “true widows”, better get back to the topic at hand.
Now, onto the media, the reason why these spiders so frequently pop up in the news is because they are often held responsible for severe injuries, deaths and all sorts of other chaotic events. Yes, they do look like the Laterodectus spiders, but as we have established, they do not possess the key toxin to make them deadly. Out of the three species found in the UK only S. nobilis is able to bite, although a few especially large individuals of the other two may occasionally be able to, and like the Widow spiders, they are not aggressive spiders and rarely bite without being severely irritated. So, to summarise, they do not possess a deadly venom and they are not aggressive (not like the Brazilian Wandering spider, go ahead, look it up, they’re awesome). But despite these facts, we still see headlines like this…
It is not all that surprising really, the White-tailed spider (Lampona cylindrata and L. murina), a spider native to Australia was held accountable for skin necrosis and ulcers for a long time. But then a scientific study by Isbister and Gray in 2003 showed that they do not possess necrotic venom and cause local pain, swelling and itchiness at most. So spiders have a history of being held responsible for deaths and injuries that they did not cause. Off on another tangent, back to Steatoda, if you are incredibly unlucky or irritate one enough that you do get bitten by a Steatoda sp. unless you have a severe allergic reaction, it will likely cause a small red bump, minor swelling and some itching at most. It won’t kill you and it won’t be necessary to have a limb amputated. These spiders are not dangerous and are not to be feared, no spider in the UK can do any real harm and only a handful are big enough to actually bite. In fact, spiders as a whole are not to be feared, there are approximately 55,000+ spider species in the world and yet only around 25 have the potential to cause any real harm to humans. And yet, they are one of the most feared animals.
Right, well this post has ended up being about the general stigma towards spiders but I guess that’s not necessarily a bad thing. The important message to remember, is that despite what the media might say, these “false widows” are not dangerous or deadly or any other scary word that they use to describe them. They are in fact incredibly interesting spiders, with their 3D, ‘messy’ Theridiidae webs and, like all spiders, are very useful to have around the house and garden. And this goes for spiders as a whole, they’re incredibly interesting animals and should be studied, not feared.
I hope that you have enjoyed this post, despite the occasional tangent and have hopefully learned something about spiders. And the next time you see one in your house or garden, take a minute to observe it, photograph and, if I’ve done my job right, appreciate it ;). Thanks for reading, see you next week.
If you’d like to read the study that showed the White-tailed spider to be far less dangerous than previously thought, then here is a link: https://www.mja.com.au/system/files/issues/179_04_180803/isb10785_fm.pdf