Spider Webs

Did you know that spider webs are sometimes used as crosshairs on many telescopes and microscopes? Or that some fisherman in the indo-pacific ocean used spider webs to catch fish? Spider webs have even been used to cover wounds because they supposedly have antiseptic qualities.

Most spiders are harmless to man. Spiders are actually beneficial insects because they cut down on the population of insects like flies and cockroaches that spread disease and are pests for humans. There are over 30,000 identified species of spider and only 60 of these species are considered dangerous to humans. I have never been fond of spiders myself, but by learning more about them and what they contribute to the ecosystem, I have learned to accept spiders as a part of the natural world that people must learn to live with.

The spider web is one of the spider’s most important contributions to the psyche of mankind. The spider web is tougher than any industrial fiber created by man, meaning it takes more energy to break it. Despite being very thin, the spider web for its size is tougher than steel. The silk is also very ductile being able to stretch up to 40% longer than its initial length. The strength and versatility of spider silk has caused researchers to try and duplicate the process in which the spider makes its silk, but these attempts have so far been unsuccessful. Breeding spiders for their silk has also been unproductive because of the aggressive nature of spiders. They sometimes eat each other if they are kept in too close of proximity. Silkworms are much at making silk for commercial purposes.

Spider webs come in a variety of shapes and sizes. All spiders spin different variations of webs depending on the spider’s species. Spiders are very sensitive to vibrations and wait in their webs until something gets caught in it. Identifying the kind of web that a spider has made will help you to identify the spider. It is important to identify the type of spider you are dealing with so you know whether the spider is dangerous or not.

• The spiral orb web is the traditional spider web shape. It is usually vertical with a spiral design around radiating axis. Orb weavers are usually not dangerous to humans.
• Tangle webs do not have the organized design that other types of webs have. These webs are messy looking and are meant to catch unsuspecting prey. The black widow spider weaves a tangled web and the female rarely leaves her web. Don’t mess with this spider’s web.
• Sheet webs are usually horizontal.
• Funnel webs are shaped like funnels. They are open on two sides, but narrow in the middle where the spider generally hides. The funnel web spiders in Australia are among the most dangerous and deadly in the world.
• Tubular webs wrap around trees. These are made by bark spiders in sheltered forest areas.
• Dome or tent webs have several knock down threads hanging above a sheet web, forming a sort of tent. The knock down webs are meant to confuse prey or knock them down onto the main web.

Cobwebs can refer to any kind of web, but the term usually applies to old webs found indoors that have been covered in dust.

In addition to making many different kinds of webs, spiders use different kinds of silk to create the webs. The spider web is made of a protein that is spun from a special gland on the abdomen of the spider known as a spinneret.

• Dragline silks are non-adhesive and used to make the outside ring of the spider web and the radial lines of the spider web that the spider can walk on.
• Capture-spiral webs are sticky, stretchy, and tough. These are spun across the dragline threads and are used to catch prey.
• Tubiliform silk is a very stiff kind of silk used to make egg sacs. Nursery web spiders use this form of silk exclusively.
• Aciniform silk is used to wrap up captured prey. It is the toughest kind of silk.
• Some small spiders also use a kind of silk to create long threads or balloons of silk that are used to catch updrafts of wind to carry the spider to a new location.

Spider webs help the spider catch its food and save it energy by not having to hunt or chase its food. Because the spider webs require a lot of protein and energy to create, and the webs often get debris and dust caught in them so they last only a few days, some spiders will eat their webs and build new webs everyday.

Then, there is the net-casting spider which does not spin webs at all. Instead, it attaches silk to its front two legs and ambushes its prey by covering it the sticky silk and then biting it. This saves it the energy of building a web, but also saves it the energy of chasing its prey. This is just one more example of the amazing ways that a spider uses its web to survive in many diverse climates.