Scientists have found that the adhesion and tensile strength of a spider's silk strands vary depending on the surface their web is located.

They believe that understanding the structure and way of construction of spider silk is a challenge worth taking.

In this study, they examined five different spider species regarding adhesion and tensile strength of a particular silk spiders use in fixing the main thread to a surface.

Like Us on Facebook

Scientists believe that this so called "safety thread" is used to prevent them from falling when they are lowering themselves and building their web's framework.

Threads remain fixed to the surface using attachment discs which can be generated by rotating motions of the silk glands that forms a special lattice pattern.

Jonas Wolff, one of the researchers, said that when they placed the spiders on glass with Teflon and a leaf of sycamore maple, they produced attachment discs on each surface.

The silk adhered so tightly to the glass surface that the threads were torn apart before they came off, he said.

The attachment discs produced on the Teflon substrate could be detached completely, he added.

Wolff noted that on the surface of the leaf, adhesion is eventually reduced to a level where the attachment discs most often come off completely.

He also believed that this evolution is caused by the fact that vegetable surfaces often contain microstructures and waxes, making it harder for herbivorous insects like spiders to walk on them.

Spiders have to face his problem if they want to build their webs between plants, he explained.

Wolff said that the reason for this behavior is because of the competition between plants and other herbivorous insects present an evolutionary pressure causing spiders to develop better adhesives.

To date, scientists are figuring out the structure and functionality of the attachment discs.

They believe that their findings will show the great value for development of ecological adhesives.