How do spiders build their webs?

Garden Spider in web

So how do spiders do it?

I have been studying nature all my life and am still totally amazed by spiders. I am astounded by what they do. Their webs are a miracle I am sure you will agree?

There is a Garden Spider female with a web hanging over my balcony and I have wondered how she created it. The balcony is around 14 ft wide, and I know that having measured it, but somehow the spider has lines to both walls and another to the ceiling, as well as one to the balcony railings.

She is suspended in space with at least 6 ft between the one wall and the centre of her web. There is something like a 40 ft drop below into a car-park.

To weave a web

Apparently the spider puts out a line of silk that may be carried by the breeze to a nearby wall, trunk, twig, leaf or other solid surface. As soon as it hits the spider senses this and runs down it as well as creating another thread to make the connection stronger.

I have never seen this myself whilst observing spiders in the wild but have seen it captured on film in a presentation by David Attenborough so I know this is how it is done. It has been filmed in time-lapse and speeded up so we can view the process.

The spider creates other main lines below and to the side of the web and then starts filling in the rest of it around the central hub point. The spider uses as many as six different types of thread to create its work and there can be as much as 60 metres of thread in a single web. This is how the orb-weavers go about it and they make fantastic webs with intricate webbing and precision.

An orb-weaver can complete making a web within an hour after it has created the basic lines to hold it in place. Some orb-weavers make a new web every night.

Orb-web spiders make their webs under the cover of darkness for obvious reasons. They are a lot less likely to be seen moving about then, whereas in the daytime a hungry bird might spot them.

I love to see spider webs when they are covered in dew-drops. They look really magical glistening in the sunlight of an early morning, as if they weren't already magical enough!

In the UK there are lots of Garden Spiders about in late summer and early autumn. The females can be recognised by their larger size. They have a white cross on the back of their bodies too.

There are other types of webs including tunnel webs that do not appear so complex but the system of spinning a web is pretty miraculous I think even if some sorts of webs do not look as attractive to the human eye. And then there are spider types such as the Hunting Spiders, Crab Spiders and Wolf Spiders that do not build webs but rely on their hunting skills to catch their prey.

Tent-web spiders

In Tenerife where I am living we have a very common spider which is one of the tent-web spiders. Cyrtophora citricola tends to live in communities of males and females. They spin large sheet-like webs that they drape over foliage and hence the name "tent-web."

Tent-web Spider

The females spin cocoons in which they lay their eggs and these hang in the middle of their webs where they can stand guard over them.

This particular species, which is also found in the other Canary Islands and in Africa, tends to spin its webs in clumps of Prickly Pear cactus (Opuntia ficus-barbarica) and in the massive spiky leaves of the Century Plant (Agave americana). Living like this presumably offers the spiders some protection from predators and humans too! Many people are scared of spiders and kill them but I think they are amazing little animals!

Copyright © 2012 Steve Andrews. All Rights Reserved.

Ladybird Spiders need our help

Male Ladybird Spider (Eresus sandaliatus). Photo by Viridiflavus.

You have probably not even heard of the Ladybird Spider but this is hardly surprising because it is a very rare creature indeed.  Named after the brightly-coloured beetle everyone knows, the male Ladybird Spider (Eresus sandaliatus) has a vivid orange-red back with four larger black dots and two smaller spots on it.  If you saw one there wouldn’t be any chance of mistaking it for something else.

Well, actually there are many other species of spiders in the Eresus genus and several of these are known as Ladybird Spiders because of their colourful appearance. These spiders are collectively called “Velvet Spiders” because of the minute hairs that cover their bodies and legs.

Endangered species

In Britain the Ladybird Spider (E. sandaliatus) was so rare it was believed to be extinct until it was rediscovered in 1980 in a small population in Dorset. The species is listed in the British Red Data Book as “Endangered” and is, not surprisingly, protected under the 1981 Wildlife and Countryside Act.

In 1993, it was thought that there were only around 50 individual Ladybird Spiders still surviving in the UK, and that they were dying out mostly because of habitat destruction. In 2000, however, there was some very good news because more than 600 separate Ladybird Spiders were counted, and this number has been increased since then to 1,000 spiders.

Since 2000, other colonies have been successfully created on the Dorset heaths which are the sort of habitat the Ladybird Spider needs. Captive bred specimens of this very rare and but distinctive spider were released bringing the number of populations in Dorset from just one to eight.

Buglife – The Invertebrate Conservation Trust

Buglife - the InvertebrateConservation Trust, has started an important campaign to help ensure the safety and future survival of this very attractive but endangered spider.  The organization is collecting funds that will be spent on carrying on the captive breeding programme, establishing new populations of the Ladybird Spider, and monitoring the existing ones.

Buglife are accepting donations to assist in this vital conservation work but will reward those helping their efforts.  All those people who donate over £20 we will be sent a special Ladybird Spider pin badge, as well as an electronic newsletter  keeping them up to date on the progress of the project. Anyone who makes a generous donation of  £1000 or more will receive an exclusive invitation  to actually visit a site where you will be able to see the Ladybird Spider in its natural habitat.

Ladybird Spider lifecycle

The Ladybird Spider species sandaliatus is also found in Europe from southern Norway to the northern parts of Italy. They make their webs as tubes under the ground and mainly feed on small bettles and millipedes.

The smaller males become adults in early September, and overwinter in their webs.  They emerge from hibernation in spring and search for females in May or June of the following year. As well as being larger in size the female Ladybird Spiders are different in appearance to the males because they are a jet-black colour all over. After mating, female Ladybird Spiders lay between 35-80 eggs. After these hatch out, the baby spiders are fed with a liquid from their mother’s mouth. The female then dies and the spiderlings feed on her body. They stay in her web until the next spring when they leave to go and make their own.

The very similar and closely related Ladybird Spider E. cinnaberinus is also known as E. niger, but the males only have the four black spots and are missing the smaller ones. It is found throughout Europe and as far as the North Africa and La Gomera in the Canary Islands. It lives in underground tube-webs too in small colonies like its cousin and is also very rare.

I am sure you will agree with me that these Ladybird Spiders are fascinating creatures. If you would like to do something to help their survival in future then please get in touch with Buglife.

Copyright © 2012 Steve Andrews. All Rights Reserved.