Dear Readers, spiders have been much on my mind this week, largely because I’ve been staying in Dorset with my mother, who is recovering very nicely from her recent spell in hospital. However, before she was allowed to come home she had some very vivid nightmares (not surprising when you have a major chest infection, sepsis, a blood sugar level of 32 and your INR (blood thickness, which is measured regularly when you’re taking Warfarin ) is >10 when it should be around 2).
‘I dreamed that the hospital was being invaded by giant spiders’, said Mum when I phoned one morning.
‘That must have been scary’, I said.
‘It was,’ she said. ‘I knew that they could only see you if you moved, so I kept absolutely still all night’.
I wondered if a memory of Jurassic Park had crept in at this point. Some spiders have excellent eyesight (jumping spiders in particular) and you wouldn’t have to move for them to catch you. I chose not to share this information with poor Mum.
‘And the nurses were just carrying on as usual’, said Mum. ‘And I said to one of them, ‘how can you keep going when the wards are being invaded by giant spiders? What can we do?’ And she leaned over me and said ‘Just trust in the Lord’.
Well. I’m pleased to relate that no giant spider invasion actually took place, though I can imagine how terrifying a night it must have been. And now Mum has gone home to Dorset, I can share the little chap in the photograph of my kitchen window (above) with you, for, just like the spiders in Mum’s dream, he is not at all what he seems.
After much debate on the British Spider Identification Facebook group, I’ve come to the conclusion that what we’re looking at in the photo is not a live spider, but the ghost of one – the complete exuvia, or shed skin, of the arachnid. This is the last moult of a male spider before he becomes fully mature, and where he is now is anybody’s guess. I wish I had seen him emerging from his skin – getting those long legs out must have been a bit of a struggle. Pretty much any spider that you see that doesn’t move at all is not actually a spider, but the shadow of one. Spiders are particularly vulnerable during ecdysis (moulting) – sometimes they get stuck and can’t free themselves, and sometimes they are pounced upon by predators. I only hope that this one got away to complete his destiny.
How can I tell that this is a male? If you look at the photo above, you will see two club-like protuberances from the spider’s head. These are the palps, and are used by the male during mating. A male spider does not jump onto a female’s back in the manner of a pigeon or a tom-cat, but is much more delicate in his approach. First, he spins a tiny horizontal web, and onto this he deposits a few drops of semen. Then he gathers the liquid up with his palps, where it clings to the hairs that coat them. Finally, when he approaches the female he uses his palps to inseminate her, after going through all the rituals that are prescribed for his particular species. If he can, he will approach a female who has just moulted, as she will be slightly less active and there is less chance of a fatal misunderstanding. For details of one spider courtship that I witnessed, have a look here.
It’s difficult getting down to species level with just an exuvia (shed skin) to go by, but my suspicion is that this chap is a Black Laceweaver (Amaurabius ferox). This is an example of a Cribellate spider – they have a special organ next to the spinners at the back that enables them to produce a very fine silk, which is then combed to woolliness by a special organ on their fourth legs. In his wonderful Collins Field Guide to Spiders, Michael J. Roberts describes the silk produced as being like the ‘smooth’ part of velcro, the hooks being provided by the legs of the unfortunate invertebrates that get tangled up in it.
You might be wondering why this spider is called a Black Laceweaver, when the male is quite clearly a rather pale chap. Well, the female, who is considerably larger and who can pack quite a nip if you handle her, is below. Please ignore all the scare stories in the newspapers about the ferocity of these creatures – they will only bite if severely provoked, and in that case I reckon the provocateur deserves everything that they get. In the battle of human vs spider, the odds are so overwhelmingly on the side of the ape that I have every sympathy with the arachnid.
There are more than 600 species of spider in the UK from tiny Money Spiders to fairly hefty characters like Fen Web Spiders. Most of the time, they don’t live in our houses at all. Those that do often leave traces that we notice once they’ve passed to get on with the next stages of their lives. Sometimes, these remnants can be extraordinarily beautiful. Just have a look at this web, from a ceiling light in Mum’s house. It is as delicate as a Bruges lace handkerchief.
Whichever little creature made it has long since gone, and, I suspect, so will the web once Mum is strong enough to get her feather duster to it. But how extraordinary are the lives of the animals that we share our houses with, and how little we notice them, or know about them. Like dreams, they seem to disappear before we understand them.
Photo One (Female Black Laceweaver) – “Amaurobius ferox fg01” by Fritz Geller-Grimm – Own work. Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Amaurobius_ferox_fg01.jpg#/media/File:Amaurobius_ferox_fg01.jpg
All other photos copyright Vivienne Palmer