Wondrous, Woven Webs
by Sandy Yearwood
Spider webs! They make you think of Halloween and sticky strands you accidentally walk into when you least expect them. In your house your mother calls them cobwebs and goes after them with a broom. The webs can be outside or inside, large or small.
But did you ever really look at a spider’s web? They are all masterpieces of engineering, whether they are the beautiful, symmetrically designed webs or a tangled mess of lines. They are constructed of, not one, but a combination of as many as six different types of silk. Most spiders produce only three to five varieties. No spider can make all six.
One type of silk, all spiders have in common is a very strong silk called drag line silk. No matter where a spider goes, the first thing he does is attach his drag line to something solid. This allows him to move rapidly up or down. It also serves as his safety belt while he constructs his web.
The silk comes from spigots in the spinnerets and is called “fibroin”. This is a fibrous protein that is insoluable in water. Produced as a liquid, it hardens immediately as it is pulled out. It is also elastic and can stretch up to a quarter of its length.
Most webs begin with framing silk which is strong and dry. Once the frame of the web is in place, the spider weaves his design with sticky silk. The spider does not stick to his web because of oil on his body.
Among the spiders that spin orb or symmetrical webs, many build and take down their webs every day. Some of these spiders work only at night an others during the day. A few of the daytime spiders also decorate their webs with zigzags, bars, bands, or other markings with a special silk that reflects ultraviolet wavelengths.
To the human eye these decorations appear whitish in color. Scientists are not sure whether the decorations are used to attract insects or to act as a warning signal to larger species such as butterflies, and birds, to go around.
Tangled webs may not be particularly attractive, but they are very practical. Once these webs are up the spider leaves them in place. If they become damaged they are easy to repair. Not only are they effective traps for insects, but they provide a hiding place for the spider as well.
Once you begin looking at spider webs, you’ll discover there are almost as many variations in design as there are spiders who create them. For example there is a spider that builds a dome in a tangled web. He hides inside and when insects land on the dome he pulls the through. Another spider builds a symmetrical web in the shape of a triangle and pulls it tight. When an insect lands, the spider lets go and the web wraps around the prey.
Remember that spider webs and cobwebs are around all year, not just at Halloween. So why not go exploring! See how many different designs you can discover around your home.