Spider webs: not just for Halloween

Location, location, location

Spiders use their webs to catch dinner.  The choice of location is key to success.

Some spiders build their webs across potential insect flight paths. High-traffic areas such as near a light or window that's lit up at night are prime sites.

Other species place webs down low where crawling invertebrates are likely to wander by and horizontal webs can catch insects if they fall off the plant they were feeding on. 

Types of spider web

British spider webs can be categorised into seven broad types: orb, sheet, tangle, funnel, lace, radial and purse.

Orb webs

These are the classic, two-dimensional webs that look like bicycle wheels or dart boards.

Orb webs are constructed with radial threads that function as a scaffold. The spider then lays down sticky threads in a spiral.

The spider waits in a head-down position at the centre of the web or lies hidden among nearby vegetation where it remains in contact by means of a signal thread. When an insect flies into the web the spider approaches the source of the vibrations, bites it and wraps it in silk, to feed on later.

The missing sector orb weaver (Zygiella x-notata) constructs a very similar web, but one sector is left completely free of spirals. A strong signal thread passes through this sector to where the spider sits in its retreat. They're commonly found on the outside of window frames.

Webs spun by Tetragnathidae spiders, the long-jawed orb weavers, follow a similar pattern to Araneus webs, but there is a hole in the centre. This is often where the spider takes up position, spanning the hole with its four hind legs. The webs can be in pretty much any orientation, not just vertical.

Theridiosoma gemmosum builds a web derived from the typical orb shape. These small webs have an open hub and resemble an inside-out umbrella. The species is rare, found on low-growing plants near water in southern Britain.

Wasp spider

Some orb-weaver spiders add decoration to their webs: an extra band of silk called the stabilimentum.

This is particularly striking in the case of the wasp spider (Argiope bruennichi). It incorporates a zig-zag of dense, white silk down the centre of its web. What this is for still isn't known, but there are a few ideas.

Triangle spider

Hyptiotes paradoxus builds an unusual web that has earned the spider its common name, the triangle spider. If a circular orb web was a pizza, the web of Hyptiotes paradoxus would be a single slice. The spider also has quite a distinctive appearance. It is a fairly rare spider, present in England and Wales but not Scotland.

Jan adds, 'Your best chance of seeing it is likely to be on yew trees in graveyards.'

Hyptiotes uses its distinctive web as a snare. The spider sits on a nearby twig and holds taut a thread that runs to the tip of the triangle. Any unlucky prey caught on the web's fuzzy cribellate silk soon finds itself completely entangled as the spider immediately releases the thread, turning the web into a net, and then tightens it around its victim.

Garden centre spider

A relatively new arrival to Britain, probably imported on pot plants from the Netherlands, the feather-legged lace weaver (Uloborus plumipes) has spread throughout much of the UK over the past 25 years.

It has set up home in garden centres - where winter temperatures don't drop below freezing - and so it is often referred to as the garden centre spider. 

Although they look like haphazard constructions, they're still effective at catching prey. These 3D webs are built by four families of UK spiders: the Dictynidae, Pholcidae, Theridiidae and Nesticidae (a single species).

There are seven species of Dictynidae spider in the UK. They create small, tangled meshes of cribellate silk, often building them over flower heads and under leaves, and also among leaf litter.

Daddy-long-legs spider

Pholcus phalangioides is the member of Pholcidae you're probably most likely to encounter, as it has become increasingly familiar as a house spider in Britain.

Fifty years ago it was quite rare here. A prolific breeder, it is now becoming very common, spreading northwards and living in centrally heated rooms all year round. 

Pholcus phalangioides is a pale, delicate spider with long thin legs that hangs upside down on its flimsy, untidy web in the corners of rooms or behind furniture. If disturbed, the spider bounces up and down and becomes a blur.

It makes a good houseguest, consuming woodlice and other unwanted household pests. It also eats large spiders.

False widow spiders

The comb-footed spider family, Theridiidae, includes the much maligned false widow spiders (Steatoda species). Their webs are loose 3D frameworks of criss-crossing sticky threads.

Steatoda webs are usually found in buildings, sheds and garages or nearby under stones, in walls and garden fences. Two of the most commonly observed species are the noble false widow (Steatoda nobilis) and the cupboard spider (Steatoda grossa).

By day, Steatoda nobilis hides away in a silken retreat. This more densely woven section looks a bit like a funnel. From dusk onwards, it hangs upside down on its untidy web, which it usually builds at high level. This non-native spider prefers south facing aspects and conservatories.

The native Steatoda grossa prefers to make its messy web in dark corners among clutter in garages and sheds. It characteristically hangs or moves about this web upside down.

Funnel webs

They're made by just one family in Britain - the Agelenidae - which includes the labyrinth spider (Agelena labyrinthica) and house spiders (Tegenaria and Eratigena species). The overall shape resembles a funnel.

Living low down among grass, brambles, gorse or heather, the labyrinth spider typically spins a large sheet of closely woven silk that extends from a long tubular retreat at the rear.

Lace webs are similar to funnel webs in that they also have a tubular retreat where the spider hides, but they are made of 'woolly' cribellate silk and the threads are more loosely spaced, looking more like lace than a silk sheet.

Only three species of lace web spider live in the UK. They all belong to the genus Amaurobius.

The webs are often spread out flat around gaps on walls, fences and window frames - particularly those of Amaurobius similis and A. ferox, while A. fenestralis webs tend to occur on dense vegetation like gorse, under stones and around cracks in tree bark.

Radial webs

This style of web has single lines of silk radiating away from a silken tube. The lines function as trip wires that alert the spider hiding inside the tube to prey wandering past. It dashes out at frightening speed.

Unlike most other types of web that entangle prey, this one simply alerts the spider to its presence. They hunt nocturnal insects such as moths and cockroaches, as well as bees and wasps.

Only a single family of UK spiders makes this kind of web: Segestriidae, which only has three species living in Britain.

Jan says 'This family has a unique leg arrangement. The hind legs hold on to the inside of the tubular retreat and the other three pairs face forward, touching the radial threads.'

Tube web spider

The tube web spider (Segestria florentina) is the largest of the UK species of Segestriidae, with females growing more than two centimetres long. The spider is black or dark brown. The base of its jaws (chelicerae) are often a striking iridescent green.

Although restricted to southern England and Wales, mainly around old ports, reports suggest this originally Mediterranean species is spreading further inland.

These spiders tend to like living in crevices in old walls.

'They sometimes even excavate a bit of the old masonry to make a hole in which to spin their tubular web,' adds Jan.

Purse webs

Only Atypus affinis builds this type of web and is known as the purse web spider.

This spider is the only tarantula relative in the UK. Its fangs are orientated differently from those of other UK spiders, projecting downwards.