It is common knowledge that spiders capture prey via carefully crafted silk webs. Researchers at The Universities of Oxford, Strathclyde and Sheffield, recently conducted a study on how the spider spins its silk and how the silk aids it in supplying meals. Spiders have an extraordinary ability to hear vibrations in the silk via its legs. The vibrations have been dubbed the “silk route,“ and it is courtesy of these vibrations that the spider is able to devour its prey.
The study determined that when spiders apply a pluck to the web it sends a vibration directly to the spider, which allows the spider locate their prey. As well, it allows spiders to locate their mates. This plucking produces a sonic vibration that is heard or detected via the spider’s eight legs. Much like the sound of a plucked guitar string; the spider’s legs detect the vibrational sound which alerts them to the exact location of their prey.
Boston University biomaterials scientist, Joyce Wong, was one of the scientists involved in the study. She is also a cellist. She had been studying spider silk for quite a number of years, but noted that she never concentrated on the sonic properties that may have been involved. She reports that the findings are opening up a new line of applications and research that had not come to mind previously.
Human beings can detect an insect or two trapped inside of a spider web by merely taking a look at the web. However, while there are species of spiders than can hunt by sight; most spiders cannot detect the location of their prey by way of eyesight because they have very poor vision. Hence, what spiders lack in eyesight, they make up for in an alternative sensory application. The spiders are able to locate and devour their prey courtesy of this silk route hearing. Spiders depend upon the vibration of the silk to lead them to trapped prey; an ability which is essential to a spider’s survival. Spiders pluck and pull at the delicate strands of the web. Each pluck delivers a stream of vibrations in every directions. The spider’s extraordinary tactile hearing is what shepherds it along the silk route. Serving as its ears; all eight of his the spider’s legs sense the vibration, leading the spider to its mate or prey.
Once prey has become entangled in a spider’s web, the spider web can vibrate on such a vast array of frequencies that the spider can sense movements as small as a 100 nanometers, which is the width of a human hair. Once the spider has utilized its tactile hearing to reach their prey, they proceed to prepare it for consumption. The spider will then bite its prey, say an insect, and inject it with paralyzing venom. The spider will then proceed to wrap the insect in silk. After the insect is wrapped in the silk, the spider will wait for the insect to perish. Once the insect is dead, the spider will then begin to vomit its digestive fluid upon the insect. This fluid serves as pre-digestive agent for the spider. From there the spider is able to suck the predigested food into his gut.
Scientists have always known how the spider successfully traps its prey. However this recent discovery of the spiders’ journey to devour their prey, courtesy of their silk route hearing, has shed new light on the inner workings and survival mechanisms employed by these silk weaving arachnids.
By Janet Walters Levite