Domestic science

Humans share their homes with a surprising number of other species, even discounting the ones they deliberately import to serve as allergen distribution machines. Autumn is a particularly good time to go spotting the spiders that cohabit with us, as many of them are grown fat and sleek on the flies of summer, and are therefore easy to spot.

The cellar spider (Pholcus phalangioides) is sometimes called the daddy long-legs, but unhelpfully, this refers to at least two other whole groups of animals, the harvestmen, and the crane-flies, neither of which are closely related. The confusion this causes is one reason why biologists insist on using Latin names instead.

The cellar spider below is currently living behind my bedside-table, coming out at night to hunt. There is a myth that this spider has incredibly toxic venom and it’s only the stumpiness of its fangs that prevent it being lethal, but this is tosh. If you’re an arachnophobe, there is every reason to leave this spider alone, as one of the things it eats is other spiders. Putting it outside will kill it at this time of year, as they’re essentially a subtropical species that has colonised the subtropical boxes humans brought with them as they spread across the globe.

When disturbed, the cellar spider does a bonkers dance in its web, which I find endearing.

The spider below is a garden orb-web (Araneus diadematus). The fact that it is currently living behind a Venetian blind in my living room some substantial distance from any sort of garden, is another reason biologists prefer to use Latin names (although the translations of some Latin names are themselves horribly misleading).

The largest spiders in the UK, in terms of overall leg-span, are the various funnel-web house-spiders of the genus Tegenaria. When I was a kid, there was a mahoosive giant house spider that lived in my parents’ shed, which in my mind was the size of dinnerplate, but in reality was probably only about the size of a Jaffa Cake. I called it Attila and fed it flying ants and woodlice.

The domestic house-spider has just the right mixture of size, chunky-leggedness, speed and fearlessness to cause worry in even the non-arachnophobic, but it’s usually docile and its bite is generally regarded as clinically insignificant. The ones you see wandering about away from their funnels are usually the boys, on the hunt for girls. The arguably more venomous hobo spider is a close relative.

The best spiders in the whole world are the jumping spiders, and if anyone disagrees, they are simply wrong. Although our native species probably can’t compete with the peacock spider of Australia for sexiness, I dare even the most hardened arachnophobe to look at a zebra spider’s cute little face and not have their heart melt. That scientists are not currently trying to breed zebra spiders the size of kittens is a damning indictment of the way grant money is awarded by the Research Councils.

The only spider that came a shock whilst touring my house for them was the one below:

It was bundled up in the corner of my front door, and I had no idea what species it was, so I gave it a gentle prod with the blunt end of a pencil to get it to show itself. I may be mistaken, but I think it’s a false widow spider (Steatoda nobilis), a non-native species that arrived in the UK, possibly on shipments of bananas. It is one of the very few species in the UK that can apparently inflict a painful and “clinically significant” bite; but to put this in context, the stings of bees and wasps are “clinically significant” too, and occasionally terminally so.

I’ve spent a lifetime telling people how cute and useful and harmless British spiders are, and that people should leave them alone rather than splatting them with a shoe. I guess I shall have to modify this to “Mostly Harmless” from now on…

Posted in Organism of the week

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• Marlowe
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