Spider Silk

Spider Silk: Evolution and 400 Million Years of Spinning, Waiting, Snagging, and Mating

By Leslie Brunetta and Catherine Craig

Spiders are best known for using silk to build orb webs, the wheel-shaped webs that look as if they were engineered. These webs, and the spider’s ability to produce them using material generated in its own body, have fascinated humans for millennia. They have inspired weavers, civil engineers, and metaphor makers from poets to designers of computer networks. Geometrical, delicate to the point of transparency, yet super strong and super sticky, these webs can stop and hold insects hurtling with tremendous speed through the air. Spiders build orb webs by piecing together a minimum of four types of silk, each having a different form and function. One silk provides strength, another flexibility, and still another a scaffold to aid the spider during construction. Scientists and entrepreneurs have spent millions of dollars trying to copy what spiders accomplish on a budget of dead bugs.

Stingless bees vs spider silk decoration

Just got a paper out in the Journal of Arachnology
Stingless bee interception is not affected by variations in spider silk decoration

Abstract
The functional significance of web decorations in orb-web spiders has been an area of intense study for well over a hundred years. Two main hypotheses, (prey attraction and predator avoidance) have had intermittent support and criticism. By varying the decoration pattern, spiders minimize the potential predation costs of constructing a highly visible signal and deter potential prey such as bees from associating decorations with danger. The prey attraction hypothesis implies that as the signal changes, so should the response of the intercepting insects. In this study, I tested the response of bees to varying decoration patterns. I show that stingless bees (Trigona carbonaria) respond to the silk decorations of Argiope keyserlingi Karsch 1878 in similar ways irrespective of the pattern of decorations. I also demonstrate that the likelihood of prey hitting the capture area is greater than that of hitting the hub area in decorated webs. Since stingless bees respond similarly to different levels of signal strength, I conclude that variation in decorations does not affect prey interception.

The Spider Awards

Wired.com’s Arachnid hall of fame.

We admit it. Spiders have become an obsession at Wired Science. It started in September when we reported on a spider-milking machine that was built to extract silk from a million golden orb-weavers, two dozen at a time, to make a 44-square foot cloth. After that, we were hooked, and we’ve found ourselves writing about an inordinate number of arachnids, and googling plenty more. But, really, who could blame us?

Fossil Spider

Scientists have unearthed an almost perfectly preserved spider fossil in China dating back to the middle Jurassic era, 165 million years ago. The fossilized spiders, Eoplectreurys gertschi, are older than the only two other specimens known by around 120 million years.

The level of detail preserved in the fossils is amazing, said paleontologist Paul Selden of the University of Kansas and lead author of the study appearing Feb. 6 in Naturwissenschaften. “You go in with a microscope, and bingo! It’s fantastic.”

Thanks, PK.

A new Nephila, the biggest so far!

A new and rare species of “giant” orb web spider has been discovered in Africa and Madagascar. In the journal Plos One, researchers describe Nephila komaci as the largest web spinning spider known to science. Only the females of this groups of species are giants, with a leg span of up to 12cm (4.7in); the male spiders are tiny by comparison. Scientists say the female spiders are capable of spinning webs that reach up to 1m (3ft 3in) in diameter.