Why is everyone in London getting bitten right now?

Helena King first knew something wrong when she felt a dull tingling below her thumb. She’d come home from spending a glorious late June day wild swimming in Beckenham Place Park and brushed off the pain until she woke up the next morning with a ‘whacking great swelling’ on her hand. 

‘It was like something from Medieval times,’ says King. ‘A huge boil erupted out of nowhere. It was super itchy with a blotchy red ring around it – a real plague throwback.’ Four days later, her boil now the size of a small grape, King spoke to a pharmacist about the swelling who diagnosed an insect bite.

A week later, King found two huge mosquito bites on her shoulder. ‘I just feel like I’m being eaten alive at the moment,’ she says and she’s not the only one feeling this way. Figures from the UK Health and Security Agency show that calls to NHS 111 about insect bites have been ‘increasing’ throughout the summer in London, with around 100 a day between July 18 and 24.

This summer, as the capital became engulfed by an extraordinary heatwave, there has been a plethora of stories from Londoners experiencing odd insect bites. Time Out’s Rosie Hewitson was playing football on Mabley Green near Hackney Marches in June when she felt something that drew a tiny dot of blood on her arm leaving a 4cm-long swollen circle. ‘I still have a little scar there, which looks like a track mark,’ she says. One north Londoner complained his ankles looked like a ‘gammy, inflamed model of the Andes’ after walking across Hampstead Heath in July. Even the London Underground has its own species of mosquito with a particular appetite for human blood and there are reports of venemous spiders ‘invading’ the capital’s homes. 

So, what’s going on? Have we been reduced to the mere pray of freeloading insects? Are the city’s tiny ravenous spiders to blame? Is the end of days nigh, complete with London’s very own plague of locusts?

Big summer bugout 

The main insects out for your blood in London are mosquitoes, horseflies, gnats and midges. And, as that Space song said, the females of these species are more deadly than the males, being the ones that seek out animal blood as extra protein for their eggs. Horseflies have a particularly brutal bite using their serrated jaws to saw into our skin like a carving knife until they break a blood vessel. Mosquitos are more stealthy predators, piercing us very precisely with their needle-sharp mouthpiece.

In the UK, these insects are usually harmless. It’s our body’s defence mechanisms reacting to the alien intrusion that causes all the irritating itching and swelling.

The key thing to know about these blood-suckers is that they’re far friskier in warm weather. ‘Insects have a special and specific relationship with heat,’ says Vicki Sims from Lady Bug Pest Control. ‘The rise in temperature sees insects grow faster and breed more prolifically. Year on year, many species, from bedbugs to wasps, are altering their behaviour and biology to follow the trends of the seasons with alarming accuracy.’

So, what does this mean for the state of our skin? Well, Sims has some unnerving news. Longer and warmer London summers mean we may see more of the insects we expect, but potentially some new ones we don’t. ‘The only thing separating us from species like mosquitoes that carry public health risks in other parts of the world, is climate, geography and more than a little luck,’ says Sims.  

Concerns about invasive species thriving in the UK are growing. Usually arriving with international shipments, traditionally ‘insect species brought over would die out relatively quickly because of our cold weather,’ says Natalie Bungay from the British Pest Control Association. ‘But as the weather warms there’s more chance they’ll survive and become a problem.’ 

Species like the Asian tiger mosquito are being monitored by government agencies (although they haven’t been found in the UK for more than a decade). ‘We don't want them here because they will bite humans all day long,’ says Bungay. The Asian hornet, which slaughters honeybees, is also being watched closely. So, while invasive bugs are a concern, they’re not responsible our prickling breakouts… yet. 

The noble false widow spider is causing a stir right now

But what about the venomous spiders? Well, one former stowaway causing a stir right now is the noble false widow spider, so-called because its globular abdomen covered in white blotches resembling a human skull looks remarkably like its notorious cousin, the black widow. It’s thought the false variety arrived in Britain on a cargo ship of bananas from the Canary Islands in the 1870s, but in the last 20 years its messy webs have been draping the country and sightings are ‘rapidly increasing’ in the south of England as our winters warm, according to Safeguard Pest Control. 

However, the British Arachnological Society (BAS), describe false widows as ‘shy and rather sluggish’ creatures. Unlike their infamous relatives, their bites are very mild and only inflicted if they’re prodded with an intruding finger or trapped in bedding or clothing. In fact, out of the 650 species of eight-legged scuttlers living in the UK, only 12 have fangs able to penetrate human skin. So, while they might get the blame for particularly gnarly bites there’s barely any evidence suggesting they’re the culprits. ‘Most rashes or wounds attributed to a “spider bite” have other causes,’ says BAS. ‘It’s almost never a spider.’

Dropping like flies 

Bug experts, however, are more perplexed that we’re scratching ourselves silly because insect populations are meant to be declining exponentially. A 2021 survey found that the number of winged critters in the UK has plummeted by nearly 60 percent in the last 17 years.

‘In our experience, we’re seeing a lot fewer insects, particularly insects associated with damp and wet areas, which most biting flies are,’ says Matt Shardlow, chief executive of conservation organisation Buglife. This is catastrophic because male mosquitoes are just as essential for pollinating flowers and crops as bees and butterflies and they’re an important food source for birds and bats.

‘It’s ironic that it’s been so dry in London, which means it may feel like there’s lots of insects about, but they might really struggle to have another generation next year because everywhere is drying up and depriving them of water where the breed and lay eggs,’ says Ray Barnett, president of the British Entomological & Natural History Society. ‘You might see a lot this summer, but that doesn’t mean we’ll see lots next year.’ 

‘I think the issue here is not so much that there are more biting insects around but that we’re in more contact with them,’ says Shardlow, who pinpoints our mushrooming lesions to the fact we’re outside more now with more skin showing and we’re opening our windows, allowing insects to enter our homes.

If the idea of bugs snacking on your skin fills you with dread, put them off by wearing clothing that covers you up, investing in good insect repellent, picnicking away from water, and, for God’s sake, resisting the urge to scratch. But the loss of biting insects should worry us more than a spate of short-lived swellings. ‘Insects are a key part of the environment,’ says Barnett. ‘If we value them, we can put up with a few bites.’

Loads of pretty balloons are going to fill London’s skies. In the name of art. 

Cool stuff to do in London this September.