What would you expect to be caught in an 80-foot-wide spider web? Birds, bats, maybe a hobbit or two? These massive spider webs, discovered hanging over a river in Madagascar, were made by an arachnid called Darwin’s bark spider – and surprisingly, they are only used to trap the standard spider fare: small insects. These webs are the largest in the world made by any single spider.

The freakishly huge webs are impressive not only because of their size, but because they are made of the toughest biological material ever discovered. The silk produced by Darwin’s bark spider is 10 times tougher than Kevlar and more than twice as tough as any previously discovered spider silk. Researchers think that the evolutionary reason for the toughness may have something to do with where the webs are built: over rivers. The silk has to be tough so that it doesn’t break and fall into the water, ruining the spiders’ work and washing away their meals.

The spider that creates these crazy webs is only found in one place in the world: the island of Madagascar, off of the southeastern coast of Africa. The web builders of the species are almost exclusively female, though juvenile males also sometimes engage in spinning webs. Scientists hope that by studying the way the Darwin’s bark spider makes its webs we can begin to understand the complex mysteries of spider silk.

The post World’s Toughest Material Makes World’s Largest Webs first appeared on Gajitz.

Spiders are known as vicious predators. They have a voracious appetite for insects and even other spiders, and they spend most of their lives just looking for food to ensnare and devour. But one Central American spider has a rather more laid back life, which it spends lounging in acacia trees and dining on stolen vegetarian fare. The Bagheera kiplingi is the only known (mostly) vegetarian spider.

A well-documented symbiotic relationship between acacia trees and a certain species of ant produces tiny, protein-rich nubs at the end of the acacia leaves call Beltian bodies. The ants eat these tasty buds, and in return they guard the trees from leaf-eating insects. But Bagheera kiplingi have a taste for the Beltian bodies as well, and they go to great lengths to steal them from the guardian ants. Being a type of jumping spider, the B. kiplingi often employ their powerful legs to jump away from the ants if they are spotted, but they have also been known to hide by dangling on a line of silk until an ant patrol has passed.

While over 90% of the B. kiplingi’s diet is vegetarian, they do occasionally dine on ant larvae or other B. kiplingi. When their body composition was studied by Christopher Meehan of Villanova University, the spiders’ chemical composition indicated a predominantly vegetarian diet, confirming scientists’ observations. Even more interesting is the fact that scientists had been observing the relationship between the acacia trees and their guardian ants for years, but none had noticed the spiders that also benefit from the relationship. It took a group of student naturalists to notice the spiders and bring them to the world’s attention.

What’s most remarkable about the spiders’ diet is that it has long been thought that spider anatomy wouldn’t allow for a high-fiber diet. They digest their food externally by liquidizing it with digestive juices before slurping it up. Just how the B. kiplingi deals with its mostly-vegetarian menu is still being investigated. And with all of the free time the spiders have – since they’re not building webs to trap prey – they build elaborate nests for their young, where even the male of the species pitches in to help with family duties. This trait is another that’s completely unprecedented in the world of spiders. The B. kiplingi is one unique little arachnid.

The post Vicious Veggie? World’s First Herbivorous Spider Identified first appeared on Gajitz.

Spider silk has been of interest to scientists for many years, mainly because of its incredible strength. Despite being made of nothing more than proteins, it is stronger than steel. Many attempts have been made to manufacture spider silk in laboratories for use in textiles and other applications, but they’ve been unsuccessful: the spiders tend to eat each other. So research has shifted toward making the spiders’ silk even stronger. A group of scientists from the Max Planck Institute saw studies revealing that there are trace amounts of metals in the strongest parts of some insects, then decided to see if they could induce the same strength in spider silk with the addition of metal.

The researchers started with a spider they found outside in a garden. They then used a technique called atomic layer deposition to add various types of metals to the “drag lines,” or non-sticky silk spiders use to reinforce their webs. The team expected the procedure to simply add a layer of metal to the surface of the silk, but they found that it actually reacted with the protein structure of the silk. The reaction made the silk extremely strong and resistant to breaking and deforming.

The result was silk that is several times stronger than unmodified silk. The possibilities are huge. Super-strong textiles, surgical thread and artificial bones and tendons are just the beginning. It may even be used to reinforce man-made textiles and other materials. No word yet on whether it will allow us to finally swing from tall buildings.

The post Tangled Web: Super-Strong Metal-Toughened Spider Silk first appeared on Gajitz.