Posted: Wednesday 24 October 2012
by Richard Jones
It’s autumn. It’s foggy. This is perfect web-spotting weather. Water droplets rest heavy on the silk strands, which now sag into a pattern of subtle curves.
It’s autumn. It’s foggy. This is perfect web-spotting weather. Water droplets rest heavy on the silk strands, which now sag into a pattern of subtle curves, rather than straight lines.
Silk is a biological marvel. The polymer protein chains produced by the spider’s silk glands are squeezed out as a liquid, but as they are teased and pulled, and as they react with the air, they quickly harden into an elastic solid of enormous strength and pliability. The usual statistic quoted is that a large garden orb web may contain more than 20m of silk, carefully glued at about 1,000 junctions, and weigh only half a milligram. Yet this is enough to support a huge gravid female spider weighing 2.25g. In other words, the web is capable of easily supporting its creator, who weighs 4,500 times as much as the fragile gantry.
The water droplets coating the web on a misty October morning actually weigh even more, but at least they are spread more or less evenly across the lines.
The majority of large, vertical webs spun across the garden path, between fading flowers or from the hedge, will be made by the garden spider, Araneus diadematus. This spider is usually distinguished by a pronounced white cruciate mark on the abdomen, or at least a pale round spot and four pale radiating oblongs forwards, backwards, left and right. The females, swollen and inflated, are full of eggs, while the males are slightly narrower and with more delicate, more angular abdomens.
But also have a look for the four-spot orb-weaver, Araneus quadratus, which is even larger and rounder and plumper. It has four white or pale yellow round spots on its abdomen, arranged like the dots on a dice.
Large horizontal webs, messily spun low down in bushes, with a funnel-shaped tunnel retreat for the spider to hide in, may be the work of Agelena labyrinthica, a mottled brown, long-legged relative of the common house spiders.
A neat round horizontal orb web stretched taught across rushes and other pond-side vegetation will have been made by one of the pale, long-legged and narrow-bodied Tetragnatha species.
The webs remain, even if less obvious, after the mist has lifted and the dew cleared, a testament to the enduring strength of the silk threads, and the patient engineer sitting waiting in the middle.