ARACHNAPHOBES PROCEED WITH CAUTION!!!
This year there was an absolute plague of House Spiders (Tegenaria species) all across Ireland and the island of Great Britain. There are always noticeable numbers of these spiders in the late summer and early autumn, but this year there were virtually swarms of them. It is possibly a cyclical occurrence but not enough is known about these spiders to say for sure. Most of the spiders were the long-legged males, which leave their own webs to seek out females in autumn. Unlike many other species of spiders female Tegenarias do not seem to eat the males, and this is why there will often be males of various sizes, as they survive each year they can grow bigger. And these spiders are believed to live to at least seven years in the wild, and twenty or so in captivity. The successful male will usually live with the female in her web for a few months and then leave just before the young hatch out.
This year I saw and photographed something quite amazing: a large female Tegenaria eating dogfood out of a dog’s bowl! The bowl had been left outside for the cats and hedgehogs to finish off, but attracted instead this remarkable creature. A crop of the image is below to show the detail – the spider is definitely eating the chicken and turkey-flavoured dogfood.
The plague of spiders has since abated, but it is worth remembering that despite their large size that Tegenarias are not aggressive. Although they easily have fangs large enough to puncture human skin this rarely happens…except in North America where the invasive European species Tegenaria agrestis is known to enter houses in the deep cold winters and bite people. In Europe it lives out of doors and does not like to come into houses, probably because it doesn’t like humans.
The population explosion of these spiders could be due to the heavy cold winter of last year wiping out predators such as small bird species. The largest spider of this species that I have recorded had an abdomen of on 23mm llong (less than an inch) and a leg span of 16cm. Their legs make them look huge, but there are larger spiders in Ireland, albeit outdoors.