October 15, 2012 | 9
“Don’t touch those webs!”
A couple of decades ago, my wife and I worked on a horse farm where everyone was explicitly instructed not to ever clean the cobwebs inside the barn. Sure, the owners themselves would occasionally, very carefully, almost surgically, remove a few targeted old cobwebs here and there, but the majority of the webs remained up at all times. Explanation? Spiders don’t bother anyone, while flies and mosquitoes bother both horses and humans.
On the other hand, for balance, there is an old Serbian proverb that goes like this: “If there were no wind, spiderwebs would cover the sky”
I assume this is said every time someone complains about the strong eastern wind, Koshava, that sweeps through the country in autumn.
And this situation – spiderwebs covering the sky – is something that happens in Mark Twain’s story Some Learned Fables, For Good Old Boys And Girls, featuring Herr Spider as one of its key characters. I read Twain’s short stories over and over again as a kid. Still love them.
Why are we so enchanted by spiders, in real life, in mythology, and in popular culture? I certainly am, always was.
There were Little Miss Moffet, and Itsy Bitsy Spider.
As a little kid, I watched, and was greatly impressed by the old film Tarantula. Later I could not help myself – just had to watch Eight Legged Freaks and Arachnophobia. And yes, Spiderman, despite its scientific…er, bloopers.
And then there are spiders in literature. I was scared by the Spider-Man in John Wyndham’s The Chrysalids. I fought the giant spiders of Mirkwood when I played The Hobbit computer game on Sinclair ZX Spectrum back in 1981 or so, after I have already read the book both in Serbian language and the original English. There was Shelob in Lord of the Rings, and Aragog in Harry Potter.
And of course, the best spider in all of history – Charlotte!
Today is the 60th anniversary of the first publication of Charlotte’s Web, the beautiful, haunting story of a talking pig and a writing spider.
Interestingly, growing up in Yugoslavia the first 25 years of my life, I have not heard of Charlotte’s Web until I came to the States. But then I had kids. And kids loved to watch the movie over and over again. So I read the book.
And to this day, occasionally, spontaneously, I start singing “Isn’t it great that I articulate!” An important and heart-felt sentiment for a writer for whom words are toys.
But not everything is fiction and myth. I am a scientist at heart. Each one of those invented characters always made me want to learn more about the real creatures.
A couple of months ago, I went to the American Museum of Natural History in New York City (thanks for the tickets, you know who!) to see their new exhibit – Spiders Live. Yes, “Live” is a good description – there are plenty of living specimens in there, many quite fascinating.
As usually happens in museum exhibits, there was plenty to learn about what we know. Anatomy, physiology, ecology, evolution, geography, behavior. Sure, there were a couple of non-spiders there, like scorpions, but it was clearly explained exactly why they are not spiders and how they are related.
One could see a short video showing how Gladiator spider catches its prey by throwing a carefully counstructed web trap on it, like this:
And they mentioned the Bolas spider which catches its prey by lassoing it in with its bolas-like ball of silk:
Interesting – to me at least, as a chronobiologist – is that the Bolas spider uses its circadian clock for an interesting function – it produces different blends of chemicals in its pheromone at different times of night (pdf) to coincide with different times when two different species of moths are flying around, each species attracted to a specific mix of aromatic chemicals.
But beyond learning facts, I was also looking at the ways the exhibit tries to include the scientific process – how we know what we know about spiders? I was looking for, perhaps, descriptions of ingenious experiments on the courtship signaling in wolf spiders, or the research on unique social, colonial spiders. Nope.
There was a part, at the end, which described how scientists collect spiders in the field, how they catch them, preserve them and label them.
And then I saw what I was really looking for. Yes! They did it! The exhibit had a really nice description of my favorite spider research ever! And there it was, The Charlotte’s Web connection, and my own personal connection! I talked about it at the last #TriSciTweetup at the NC Museum of Natural Science in Raleigh NC, for the inaugural Lightning Talks with Brian Malow on Thursdays at the Daily Planet Cafe:
Back in 1948., zoologist H. M. Peters was studying how spiders spin webs. He was getting tired as he had to do all of his research late at night, when spiders spin their webs. So, he asked his friend Peter Witt, a pharmacologist, if there is anything that he could give to spiders that would make them spin during the day. Peter suggested amphetamines. It did not work. Spiders kept weaving at night. But, oh my, their webs looked crazy! They were like impressionist art!
Peter Witt was an amazing person, a wonderful man. I had the fortune to meet him once, in 1998, just a couple of weeks before he died. He was the Head of the institute for brain and behavior at Dorothea Dix hospital in Raleigh, now unfortunately closed.
Intrigued by the results his friend Peters got when giving spiders amphetamines, he turned his own research into that direction, using spider webs as windows into the way different chemicals affected the nervous system. Some of those were pharmaceuticals of the day. Others were drugs found relatively easily on street corners back in the 1950s and 1960s. Both were of interest to science, of course, for different reasons.
Different drugs had different effects on the shapes of the web. In high doses, almost every drug resulted in highly irregular webs. But at carefully chosen lower doses, there were some interesting differences. For example, under the influence of caffeine, the webs were vertically shorter but horizontally wider, as spiders made larger angles between the radial spokes of the web.
The most striking was the effect of LSD-25. Yes, LSD. This is the only drug which resulted in webs being more carefully weaved and more perfect than the controls.
Charlotte? Is that you?
Many years later, I was teaching a lab at NCSU in animal physiology. Part of the lab was a project, done by students under my supervision. Some students did projects on humans – each other. But the other half used animals. Invertebrates, as there was no time to get an IACUC (institutional animal care and use committee) approval for use of vertebrates (that is a long and difficult process).
One of my students decided to use Peter Witt’s experimental protocol, applying a chemical that he never used way back then – serotonin. Result? Spiders made decent webs, but they took about twice as much time to make them. They went slow about it. They made perhaps half of the twists of the spiral before deciding that was the end, leaving about twice as much space between the loops of the spiral.
Spider brains are large and complicated. They are so large they can’t even fill just the head, a part of them fills the thorax. Of course, spider brains are difficult to study. Not to mention that we do not have a spider genome sequenced yet so we do not have the tools to monitor what is happening in a spider brain. Thus, this line of research has been largely abandoned.
But it was not all in vain. Apart from being able to categorize substances along the lines of their effects on spider webs (often corresponding to their effects on human brains), this method now has a place in agriculture. Placing a few spiders in a field or orchard overnight and taking a look at the webs in the morning can tell the researcher if there are pesticides there, and perhaps which class of pesticide if not the exact kind.
Perhaps there is something in the air that can induce a spider to write “Terrific” and I’d love to know how it does that.