Sparkling in Sunshine, Anchored in Wind -The Symbolic, Scientific Spider Web
Spider webs are artistic and practical, with as many complex layers as human society. Some people ignore or destroy them. Discerning people appreciate them. Imaginative people see them as symbols of both good and evil with their intricate beauty and predatory purpose. Perceptive people see them as tensile bridges across figurative and literal chasms.
Spider webs are miracles that spiders weave in the middle of ordinary human lives. Spiders have been around for at least 380 million years and scientists estimate that there may be about 180,000 spider species. Spiders are not insects, but what scientists classify as arachnids, a classification that includes daddy long legs, scorpions, mites, and ticks. Insects have six legs, wings, and antennae. Spiders have eight legs.
Spiders are Self- Reliant
Spiders build their own homes and capture their food supplies. Spiders are the only creatures that incorporate silk into their daily lives by spinning webs out of silk that they produce with their own bodies. They use their webs to travel or “balloon” from one place to another, as protection at the entrance of their dwellings, to encase egg sacs, and to trap insects for food.
The Composition of Spider Webs
Spiders have seven pairs of silk spinning glands called spinnerets that are located either in the middle or at the end of their abdomen. Each spinneret is unique and the spider uses each to manufacture different kinds of silk. Disk silk leaves a zigzag pattern and strengthens the dragline. Safety line silk gives the spider an anchor.
Orb web silk gives the web strength and stretchiness. Sticky catching silk traps and captures prey. Swathing silk wraps and immobilizes prey. Tangling silk tangles prey. Egg sac silk keeps baby spiders safe. The spider manufactures the silk as a liquid, but it comes from its glands as solid silk fibers. The Nephila spider’s silk is the strongest natural fiber known to humans and humans use it to make tote bags and fish nets.
The Specific Spider Web
Tangled spider webs consist of a shapeless jumble of threads attached to a support such as the corner of a ceiling. Cobwebs are tangled webs that have collected dust and dirt. Black and brown widow spiders and common house spiders make tangled webs. The orb web, that looks like a wheel with spokes, is the most common spider web. Spiders that weave the orb web include humped spiders, bolas spiders, silk spiders, and shamrock spiders.
Sheet webs are composed of flat sheets of silk between grass blades or shrub or tree branches. The doily spider, the filmy dome spider and the platform spider spin sheet webs. Gum-footed webs are made up of tightly woven silk strands attached between two branches. When an insect is trapped in the web, its struggles break the lines and move the web up, lifting it off the ground so it can’t escape. Redback spiders make gum footed webs. Horizontal Line webs are composed of one line of sticky droplets that stretch across vegetation. When an insect hits the line the loose silk tangles the prey. Cribellate and pea sized spiders make these webs.
Bolas spiders design bolas spider webs. The spider sits on a horizontal line and spins a single line with a sticky silk tip that it dangles from its leg. When its prey comes toward it, the spider swings the silk in a circle and captures it. The triangle spider creates triangle webs. It waits at one end of the web for an insect to land and shakes the web so the insect can’t escape.
The Mythological and Historic Spider Web
Spiders and their webs are familiar figures in the mythology and history of the entire world. According to the Roman poet Ovid, spiders and their relatives derive their scientific name, Arachnida, from a mortal woman in Greek mythology name Arachne.
An exceptionally skilled weaver, Arachne challenged Athena, the Greek Goddess of wisdom, law, and justice just to name a few of her titles to a weaving contest. Athena wove a life like tapestry and when Athena saw the perfection of Arachne’s weaving, she destroyed it. Overcome by grief, Arachne hanged herself and Athena took pity on her. Athena changed Arachne into a spider while the rope she used to hang herself became a cobweb, and proclaimed that Arachne would weave a spider’s tapestry, a web, throughout eternity.
The sacred writing of ancient India records that a large spider created the universe, weaving a web from her glands and sitting in its center directing its motion. The earth is part of her web and she is free to decide whether or not to consume her creation as many spiders do their webs to clear her way to spin a new universe.
At least three verses in the Old Testament of the Bible mention spiders. Proverb 30:28 mentions the spider as a little but exceedingly wise creature that “taketh hold with her hands and is in kings’ palaces.” The spider’s web symbolizes the hypocrite’s hope in Job 8:14 as well as of the disobedient Jews’ works in Isaiah 59:5.
Spiders are featured in historical stories of people pursued by various dangers, including Mohammed and St. Felix of Nola. A spider spun its web over the entrance to their hiding place and noting the intact web, their pursuers decided that no one had passed that way and went on their way.
King Robert the Bruce, crowned King of Scotland in 1306, had a mission to free Scotland from the English Army. Defeated in battle, Bruce escaped and hid in a cave for at least three months. Discouraged, he thought about leaving Scotland for good. While in hiding, he watched a spider building a web over the cave entrance. The spider constantly fell as it tried to weave its web, but the spider kept working and finally finished the web. Robert the Bruce decided that he would persevere like the spider and continue to fight for Scottish independence. He won the fight.
The Enduring Spider Web
In December 2008, British paleobiologist Martin Brasier of Oxford University announced that a 140 million year old web had been found in a small piece of amber that an amateur fossil hunter had picked up on a beach on England’s south coast two years earlier.
In October 2009, the Telegraph newspaper in Britain reported that an amateur fossil hunter looking for fossilized dinosaur footprints on a beach near Bexhill in East Sussex instead found a Prehistoric piece of amber containing threads of a spider web that a spider had spun while dinosaurs still roamed the earth. Charred bark and burnt sap inside the amber indicate that the trees producing the resin had been burnt in a fire and produced the resin to protect them against further damage. Eventually the amber ended up in a large lake bed, until uplift and shoreline erosion exposed it.
Dating to 140 million years ago, the spider web resembles those of modern orb web spiders with its tiny tangled threads connecting to each other in a rough circular pattern. The miniature threads measured about 1/20th of an inch long and they are suspended in bits of burnt sap and fossilized vegetable material. The discovery of the amber fossil suggests that orb web spinning spiders existed before flowering plants appeared on Earth, triggering an explosion of flying insects.
In 2008, the amber ended up in the hands of palaeobiologist Professor Martin Brasier of Oxford University, who studied the fossil and published his findings in the Journal of the Geological Society. Professor Brasier said, “This amber is very rare. It comes from the very base of the Cretaceous period, which makes it one of the oldest ambers anywhere to have inclusions in it.”
The fossil spider web threads closely resemble those of modern orb web or garden spiders which deposit tiny sticky droplets along their web threads to trap their prey. Professor Brasier noted that “We actually have the sticky droplets preserved within the amber. These turn out to be the earliest webs that have ever been incorporated in the fossil record to our knowledge.”
According to Professor Brasier the details of the amber spider’s web matched the details of the spider webs in his garden. To reconstruct the webs, scientists focused their microscopes on the amber from 40 different positions, tracing it through its layers and then splicing it together again using a computer technique called confocal microscopy.
The Inspirational Spider Web
In February 2012, scientists at the University of Akron announced that they have developed an unusual synthetic thread resembling the silk that an orb spider spins to make its web. They call their material beads on a string (BOAS) because it looks like beads on a string in a circular web, although the synthetic beads on a string are glue droplets. The synthetic version of the orb spider’s web design has potential to be used as strong and flexible sutures containing medication embedded in the bead like structures. The researchers developed the new biocompatible thread after consulting doctors specializing in wound healing.
Vasav Sahni, University of Akron polymer science graduate student is lead author of the article entitled Spider Silk Inspired Functional Microthread, published in the American Chemical Society Journal Langmuir. He said, ‘We have been very interested in architecture of adhesives produced by spider and were very intrigued to understand why spiders use the BOAS structure.
Sahni’s fellow research team members, Dr. Ali Dhinojwala, chair of the Department of Polymer Science, Maurice Morton, Professor of Polymer Science, and Disha Labhasetwar, an NSF-REU students with the Department of Polymer Science at the University of Akron created the BOAS replica by copying the methods that spiders use when they spin silk.
According to Vasav Sahni, the scientists used fluid mechanics concepts to vary the size and spacing of the glue beads and replicated spider silk threads with materials such as nylon. He said that he and his colleagues designed and constructed equipment to develop the threads. Instead of putting individual glue drops on a string to release the medication, the researchers developed a technique to uniformly coat the threads with glue. The glue forms waves that transform into beads creating larger contact areas and releasing adhesive strength when peeled. The beads also have the possibility of creating a platform for medication to be placed and released.
The Artistic Spider Web
The artistic spider web is exhibited in ordinary gardens, woods, and trees instead of art museums and it transforms everyday life into a work of art appreciation.
Paul Hillyard, The Private Life of Spiders, Princeton University Press, 2008.Rainer F. Foelix, Biology of Spiders, Oxford University Press, USA, 2nd Edition, 1996.
Herbert W. Levi, Lorna R. Levi, Spiders and Their Kin: A Golden Guide from St. Martin’s Press, Golden Guides from St. Martin’s Press, 1st Edition, 2001
COPYRIGHT NOTICE All of the material on this website is copyrighted. You are free to link to any of the articles as long as you credit me as the author. firstname.lastname@example.org