Leslie Brunetta

Here's a report of gossamer masses startling people living in the Macedon Ranges shire of Victoria, Australia. The ability of young spiders to balloon is made possible by super-strong major ampullate silk, the silk araneomorph spiders use to rappel and to construct the strongest lines of their webs. Jumping spiders use it as their safety line. You can read more about ballooning in Chapter Five of Spider Silk, "Triumph Over Thin Air." One of my life's goals is to witness such a mass gossamer waft. Read More 

We're proud to announce that the Boston Authors Club--the oldest continuous authors group in the US, founded in 1899--has given Spider Silk a Highly Recommended Book Award. Take a look at the awards page to see the other award winners.

Nephila spiders are big, they're bold (in terms of web coloration, that is), and now we know they're old, too--more than 165 million years old, the approximate age of a fossil just described as a Nephila by veteran spider fossil researcher Paul Selden and colleagues ChungKun Shih and Dong Ren. These gorgeous spiders are also known as the golden orb weavers because their huge webs range in color from pale yellow to vibrant gold. We write about why spiders would have evolved to construct such obvious webs--and why insects still fly into them--in Spider Silk's tenth chapter, "Now You See It, Now You Don't."

Named Nephila jurassica in honor of its age, this fossil is the oldest Nephila fossil yet found and hails from a site in present-day Inner Mongolia that has already yielded exciting numbers of arthropod fossils and may contain more spider bounty. It's startling to consider that, as far as spiders have been concerned, the dinosaurs were interlopers who showed up and then disappeared rather quickly.

Here's how to think about N. jurassica in the history of spiders: The oldest spider fossil (a mesothele) yet found is 290 million years old, or 130 million years older than N. jurassica. The oldest araneomorph fossils are 225 million years old, or 60 million years older. And the oldest known fossil of an araneoid--the group containing all vertical-orb weavers, including Nephila, and spiders evolved from vertical-orb weavers--is about 175 million years old, or about 10 million years older. We can't tell from this fossil whether Nephila jurassica wove golden webs, but its size certainly indicates that, like today's Nephila, it wove giant webs and could wrangle with large insects. Arthropods don't fossilize easily. So every new spider fossil is a treasured key to the distant past. Read More 

If you're not already one of the two-million-plus viewers of Hummingbird Cam, check it out soon to catch the current chicks before they fly the nest. Don't fret if you miss them, because the mother will soon lay another clutch of two eggs if she sticks to her pattern of previous years.

But whether the nest is full or empty, take a close look at it. The mother hummingbird has bound all her building materials together with spider silk. Spider silk offers this mother the perfect combination of strength and flexibility: the nest actually stretches with the growth of the chicks.

Hummingbirds aren't the only birds to use spider silk in nest building. I haven't been able to find any research on whether birds are picky about the kinds of spider webs they choose to filch. Do they prefer araneoid webs, with their super-stretchy flagelliform catching lines and aggregate protein glue? Or non-araneoid araneomorph webs, with their dry cribellate catching silk? Do different birds prefer different kinds of silk? If you know of any research pointing to answers, please let me know. Read More 

Our publisher, Yale University Press, featured Spider Silk on its blog this week.

We were excited to learn today that Spider Silk is a finalist in the Nature category in ForeWord Review's 2010 Book of the Year Awards list!

Part of the reason it's so difficult to create synthetic spider silk is that we still don't know exactly why natural spider silk is so strong, stretchy, or tough. We have a general understanding: certain arrangements of silk protein molecules give rise to these various properties. But we're still trying to figure out exactly what's going on at the scale of the atoms making up these molecules. We know that silk fibers are made up of both crystalline subunits, in which the molecules interlock in very organized and repetitive patterns that give rise to strength, and "amorphous" subunits, in which the molecules are relatively disordered. The amorphous subunits lend the fiber the ability to deform, which allows it to stretch or absorb impact. Still mysterious is exactly how these subunits arrange themselves and connect within the total unit of a silk fiber. After all, to know this we would have to be able to view the atoms within the fiber molecules directly. We can currently view them only indirectly, using technologies such as x-ray crystallography.

But researchers can use existing knowledge of silk protein structure to build and test models of how these atoms might link together. After playing with different proportions and arrangements of the two types of subunit, a team of researchers from Germany and China have proposed a new model that they believe could help in the design of synthetic spider silk. Even if you're an English major (like me), if you've read Spider Silk, you can skim this paper and get the gist of it. If you want a precis, you can read this article from Deutsche Welle, which ends with a much-appreciated plug for arachnology. But like so many articles on spider silk research, this one, too, is mistitled: although this research offers a promising approach to synthesizing a fiber like spider silk, we still haven't untangled all the secrets of real spider silk. Read More 

Charles Darwin was born 202 years ago today.

Although spiders don't figure much in On the Origin of Species, Darwin--an inveterate bug hunter--delighted in their variety and behaviors. He records some of his observations on "Aeronaut Spiders" in The Voyage of the Beagle:

"On several occasions, when the 'Beagle' has been within the mouth of the Plata, the rigging has been coated with the web of the Gossamer Spider. One day (November 1st, 1832) I paid particular attention to this subject. The weather had been fine and clear, and in the morning the air was full of patches of the flocculent web, as on an autumnal day in England. The ship was sixty miles distant from the land, in the direction of a steady though light breeze. Vast numbers of a small spider, about one-tenth of an inch in length, and of a dusky red colour, were attached to the webs...."

You can read on by going to the December 6, 1833, section of Chapter VIII.

Evolution is in the air today. Read More 

The "conchicolous habit"--hermit crabs have it, some bees and wasps have it, but a few spider species lift shell dwelling to new heights: they use silk to hoist their prefab homes into the air. A BBC crew working in Madagascar has finally caught the efforts of one of these species, Olios coenobitus, on film.



O. coenobitus is in the family Sparassidae, the huntsman spiders. At least one other species, Pellenes nigrociliatus, a jumping spider (family Salticidae), has also been found living in suspended snail shells, in Poland. Neither of these spiders can produce the stretchy silk used in the catching spirals of orb weavers and their descendants. In fact, few spiders in either of these families make any kind of web. Their hoisting ropes consist of major ampullate dragline silk, the super-strong silk araneomorph spiders use to rappel. In the lab, these spiders have been observed to lift shells more than 20 times their own body weight.

It might seem inconceivable that the same strange behavior would evolve in two species of spider that aren't terribly closely related. But it looks strange only to us humans. An empty shell isn't so different from the burrows spiders dig themselves or the crevices in bark they often occupy. And spiders frequently use silk to suspend killed prey and egg sacs. They pull on silk threads all the time to bring them under tension. We'll probably never know exactly how this feat evolved, but many spiders already had the tools and behaviors needed to accomplish it. Looked at that way, it's surprising this behavior hasn't evolved more often. But then again, even these spiders' closest relatives get along fine without it. In evolution, "good enough" is good enough.

Read how the film was made here.  Read More 

We're thrilled with the most recent reviews of Spider Silk from BioScience, the Quarterly Review of Biology, and Choice, the leading review journal for academic librarians. Choice deemed Spider Silk an "Editor's Pick," calling it "wonderfully entertaining." Please take a look at excerpts from these reviews at our press/links page. Read More