Wasp Spider (Argiope bruennichi) Photo by Oliver Kane

Dear Readers, you might think that most of the spiders that crop up in the UK are ‘a bit boring’ compared to those found in the tropics, but have a look at this beauty! This is a female Wasp Spider, found in Long Lane Pasture here in Finchley – the site is right next to the North Circular Road, but punches well above its weight in terms of plants and wildlife, largely due to its amazing volunteers.

Female Wasp Spiders are pretty much unmistakable – the one in the photo looks enormous, but actually they only grow to about 15mm long. The males are much smaller, and are very easy to miss.

The webs are also pretty distinctive: they contain a cross made of a different, more robust kind of spider silk. This helps to stabilise the web, and one theory is that this ‘stabilimentum’ is used because the main prey of the Wasp Spider is grasshoppers, which are pretty robust and vigorous insects. The patterns made by the stabilimenta are also thought to reflect UV light in a way that attracts prey to the web.

Wasp Spider web showing stabilimentum (Photo By Charles J. Sharp – Own work, from Sharp Photography, sharpphotography, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=61573410)

Wasp Spiders are mainly found in grassland, but seem to be fairly adaptable – my friend L found the spider in the photo below in gorse at Thorpeness.

Impressive as the Wasp Spider is, her relatives in other parts of the world have taken colouration and web design to a whole new level.  Have a look  at some other spiders in the Argiope genus below…

Argiope flavipalpis from Ghana (Photo By Charles J. Sharp – Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=149790284)

Argiope sp in Tanzania (Photo by By Muhammad Mahdi Karim – Own work, GFDL 1.2, https://commons.wikimedia.org/w/index.php?curid=7164693)

St Andrew’s Cross spider (Argiope keyserlingi) from Australia (Photo By Summerdrought – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=72803212)

Back to ‘our’ Wasp Spider. As is usual with spiders, mating is a bit of a tricky affair – the female will eat the male spider given a chance. In order to avoid this, male Wasp Spiders hang around waiting until the female has had her final moult – at this point, her jaws are still soft so she can’t murder her mate. However, the male will try to ‘plug’ the female, to prevent other males from mating with her – to do this, he uses one of his pedipalps to position the package of sperm. Pedipalps are those ‘boxing glove’ appendages that you sometimes see next to the head of the spider. Once in place, the pedipalp breaks off, preventing other males from mating. However, the male spider has only two pedipalps, so only two chances of passing on his genes.

As the female can also only mate once, due to the ‘plug’, she produces a lot more eggs than you would expect for a spider of her size – as she will only ever have one clutch, it’s important for her to ensure that at least some survive. Eggs are laid inside this rather elegant egg sac, which gives them some initial protection.

Wasp Spider egg sac (Photo by  Bj.schoenmakers – Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=21007077)

Interestingly, Wasp Spiders, which were once confined to the very south of England, seem to be moving north – global warming is shuffling everything up, and it will be interesting to see where these fascinating arachnids eventually end up. Do let me know if you’ve spotted any¬