Monday, November 8, 2010

What a line - a dragline, I mean!

About a month ago, I was walking and observed this extremely long spider’s dragline dangling over the driveway. My husband had just drove speedily under it and it was still swaying in the breeze.

It reached from the top of a Sweetgum tree, over the driveway and then to a Norway Spruce, meandered through the branches and then up to the beautiful web, as pictured here. I was amazed, quickly ran home and grabbed a measuring tape and camera. It measured over 20 feet long. I wanted to learn more - how could it still be intact?

A spider makes a new web daily and uses a dragline for making the web's outer rim and spokes as well as for a lifeline. Spider silk, made of proteins, has a tensile strength comparable to high grade steel and is very stretchable and has a high toughness similar to nylon. It is so amazing that labs all over the world are carefully studying its composition and mechanics in hopes of reproducing it someday for human needs. 

1 comment:

  1. Great picture! This dragline looks more like rope than spider silk. I somehow still managed to miss it driving by in the morning... It's amazing that the spider managed to span two trees so far apart and so high up!