Ian Carle, our Nature Reserves Manager explores the multiple different uses of silk within the spider community. All spiders produce silk, but if you thought they just used it to catch their prey read on…

Wrapping

All species of spider wrap their eggs in silk to protect them from drying out and extreme heat or cold. Wrapping them in silk provides a defence against parasites and predators. Some species such as the Nursery Web Spider (Pisaura mirabilis) construct an egg-sac that enables the female to provide the ultimate protection for her eggs – the egg-sac she produces is robust enough for her to carry it around with her. She will then construct a nursery web, hang up her egg-sac and stand guard until the eggs hatch and the youngsters disperse! The Nursery Web Spider is common in areas of shorter vegetation in our area.          

Sputnik Spider (Paidiscura pallens) – tiny spider identifiable from the distinctive egg-sac. Found on the underside of the leaves of broadleaved trees, with a preference for Oak. Old Park Wood Nature Reserve is a good place to spot them.

Shelter

Not all species of spider like to carry their egg-sacs around with them, some will use silk to construct a shelter where they can guard their egg-sacs. Species such as the Furrow Spider (Larinioides cornutus), found in wetland sites such as our Frogmore Meadows or Blagrove Common Nature Reserves, use silk to join the tops of grass stems together to form a refuge. Ground dwelling species will make a silken cell under stones, and species found in low growing vegetation will fashion shelters out of rolled leaves.

Courtship

Silk has a role to play in the courtship behaviour of all spiders. Non-web building species such as jumping spiders lay down strands of silk as they move around. These strands contain chemical clues about the spider that made them – enabling males to find females and possibly even whether the female has mated or not.

The Common Zebra Spider (Salticus scenicus) is found in gardens so there’s a good chance you could get to see one!

Ballooning and Rigging

As an eight-legged creature how do you colonise new areas? Well, the obvious answer with all those legs is to walk and this is the method used by some species, however other spiders have taken dispersal to a whole different level using silk! Two techniques are involved – ballooning and rigging. Ballooning involves the spider or spiderling – the young of a spider - moving to the highest available point, such as the top of a flower, lifting its abdomen in the air and allowing the breeze to draw a strand of silk from its spinnerets – silk-spinning organs. When the strand of silk is long enough the lift provided by the breeze is enough to pull the spider up into the air. If you’re out for a morning walk you might be lucky enough to see grassland covered in sheets of silk – this phenomenon happens when thousands of tiny spiderlings balloon at the same time. Species such as the money spider (Erigone atra) use the ballooning technique – they’re the tiny shiny black spiders that appear out of nowhere on our clothes!

Rigging is when the silk strand catches on to adjacent vegetation, the spider uses the taught strand of silk as a bridge – next time you watch a Spiderman movie you’ll be seeing him move from skyscraper to skyscraper using a highly modified version of rigging! In the real world, this technique is used by spiders such as the Daddy Long-legs Spider (Pholcus phalangioides) often found in our homes.

Thank you to David Carr, Herts Spider Recorder, Herts Natural History Society for the advice and expertise which he has added to this article.

Find out more

For more weird and wonderful facts about spiders, search our Wildlife Explorer pages.