A long-legged spider crawling away from its web

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Invasion of the giant spiders? Not quite

Giant spiders are invading Britain's homes - if media reports are anything to go by. Spider identification expert Stuart Hine explains why we see more spiders in autumn, and what you should do if you spot one.

False widow spider bites have been a hot topic in recent years, along with reports of bumper crops of house and garden spiders, and news that city spiders are getting fatter.

Spider season: looking for love

Warm weather contributes to more spider sightings, but this doesn't necessarily mean more spiders, says Hine, who spent many years dealing with the Museum’s spider identification requests.

Spider sightings always peak in the autumn when the males of many species reach adulthood and wander about looking for females, he says.  

With warmer weather, we keep our doors and windows open longer into spider season, and let more of the wandering males in.

'They aren't bigger, and there aren't really more of them. What we can say is that because of the weather and our windows and doors remaining open, there are more observations of some of the larger species that enter our homes,' says Hine.

A warm and dry autumn provides a longer season for many of the male spiders, who will roam around for longer rather than finding a dry garage or attic to hide in when it's wet.

'The kindest thing anyone can do is let them outside. They are only looking for one thing, and that's the lady spider,' says Hine.

House spider surprises

The Museum's Identification and Advisory Service gets a lot of reports of house spiders, the generic name given to a group of large, long-legged spiders in the groups Tegenaria and Eratigena. Males can have a leg span up to 120 millimetres, and they are usually brown and hairy with dull stripes on the body.

House spiders are not as common as they used to be - homes are now better sealed and central heating and more disturbance makes them dry and unwelcoming to Tegenaria and Eratigena.

'There is a generation now that have never seen these things before, whereas going back 20-30 years it was just something you accepted,' says Hine.

Tegenaria and Eratigena spiders can bite if picked up, but the effect of their venom is small, so getting bitten is unlikely to cause any serious complications.

A garden cross spider on its web

Araneus diadematus, the European garden spider. The bodies of females can be up to 20mm long. Their colour ranges from dark grey to light yellow and orange, but all have large white dots forming a cross on their back.

Garden giants

One spider that benefits from good summer weather is the European garden spider, Araneus diadematus, also known as the garden orb-weaver or cross spider. People often spot the females sitting in the middle of their large webs in gardens or across doors and windows.

When it's a good summer, but not bone dry, it's good for a lot of insects, which is the garden spider's main food. Hine explains, 'In years like this more of them reach their maximum size and there's enough food to support more of them.'

However, the turn to colder and wetter weather will stop insects flying and stop the garden spiders feeding.

Sinister false widows

Reports of false widow spiders continue to rise. The term false widow actually describes several species of spider, but the one that gains the most attention is Steatoda nobilis, the noble false widow spider.

S. nobilis has been in Britain for over a century, probably after being introduced in ship cargo from the Canary Islands or Madeira. The species has been expanding its range north in Britain since first establishing itself on the south coast. Hine says that part of the increase in sightings is due to greater numbers and wider distribution, but also because people are more aware of them.

False widows attract attention as being one of the few British spiders capable of delivering a venomous bite. However, they will only do so if they are trapped or squashed, often in clothing.

'They're not entirely harmless - these things can bite under certain circumstances. But wasps and bees sting too and we don't have that same level of fear of them. This spider has an unwarranted reputation of being so much more sinister,' says Hine.

A false widow spider on someone's skin

Steatoda nobilis, the noble false widow spider. Males can reach up to 10mm in size. They have reddish-orange legs and a brown bulbous body with cream-coloured markings. The females are larger - up to 14mm - with a rounder body and less visible markings.

 

Spider bites

Hine has been bitten three times by false widows, and each time has experienced 'a slight sting and a little numbness in the area'.

Reports of extreme reactions are more likely the result of related infections from exposure of the wound.

The best advice if you are bitten, says Hine, is to keep the area clean and avoid scratching to reduce the risk of infection. Antihistamines can relieve the itchy feeling. The NHS website has more advice on dealing with bites.

As the awareness and numbers rise, Hine predicts it will be something people gradually come to accept, like the possibility of being stung by a bee or wasp. 'I've been bitten and I've survived.'