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Category Archives: Spider science

Ground control to Major Charlotte . . .

06 Dec

One giant leap for spiderkind – a lot of leaps, actually

The universe’s most well-traveled spider, a Phidippus johnsoni with the grand name of Nefertiti, died recently in what was supposed to be her quiet retirement home. Reporters made much of how this chunky, red-and-black jumper not only thrived in her 100 days aboard the International Space Station but withstood the rigors of launch, re-entry, and being shuttled about the country with apparent good grace. Nefertiti seems to have reached the end of her brief natural lifespan in the warm confines of an exhibit at the Smithsonian’s National Museum of Natural History.

Spiders have the right stuff, forgive me trotting out that phrase. They’re focused, efficient, and as taciturn as any Neil Armstrong. This particular arachnaut, a regular Sally Ride, had a simple mission that she performed with grace and energy: catching flies. And the wondrous thing: she did it in zero gravity, an environment no earthly spider could be expected to grasp. Think of those millions of years of earthbound instincts, honed to an unimagineable degree … and yet this jumping spider was all feh, I can do this—I’ll just adjust the trajectory here and the thrust there, disregard millennia of sensory input, and boom: bug soup.

What next! Spiders from Mars? Oh. Carry on then, Ziggy.

I don’t think any old spider could have done it. Jumping spiders are the brains of the outfit. Equipped with sophisticated, unblinking, networked cameras around their little heads, they see and hunt famously well. They’ve been observed sneaking up on prey that they can’t even see, calculating how to creep up under cover and burst out at just the right instant. It would be like you stalking a pizza delivery guy walking along on the other side of a tall fence, figuring out when he’s going to stop and tie his shoe or check his text messages, pursuing him around the corner, and then out you pop through a loose board and snatch his pie. Yep, it takes thought.

Nefertiti got her ticket to ride thanks to an 18-year-old Egyptian named Amr Mohamed, who won the YouTube Spacelab contest with his idea for a jumping-spider experiment. (There was a second arachnaut, a zebra-striped Salticus scenicus named Cleopatra, but alas, she died in orbit.) Once aloft, astronaut Suni Williams took the spiders under her wing and blogged about them. She remarked about Nefertiti: “She is sort of scary. I am so glad I am not a fruit fly. I opened up the habitat and actually saw her running around at full speed looking for something to eat. It was difficult to even get a steady picture.”

What, no Tang? Nefertiti is hungry, and she’s looking at you.

Watch her do it. It’s funny how earthlike it looks. She does that classic Salticid prowl, but I think she’s hanging on to the surface a bit more consciously, as astronauts do. Can’t see it, but surely she’s letting out a silk dragline before the leap to reel herself back in if she misses. But jumping spiders always do that on earth, too.

Nefertiti was not the first spider in space. Experiments involving zero-G web building by spiders also took place aboard Skylab (that’s old-school space program, kiddies), on the space station twice before, and on the shuttle Columbia. Australian high-school students designed Columbia’s science module to see whether eight garden-variety orb spiders could do their weaving and hunting jobs in space. Those spiders perished when Columbia was destroyed during re-entry in 2003.

Until recently, a brave little website by the Glen Waverley Secondary College devoted to that aborted spider experiment was still archived on the web, drifting forlornly through cyberspace. The tab labeled “Results” was blank.

But there’s more to that story, and not really about spiders but about science and humans. Most of the spider data was lost along with the shuttle and its crew, but spacecraft did fly again. The teenagers who planned that experiment with such care resolved to let their work stand as homage to the people who venture into space. There will be other experiments, schoolchildren will dream them up, and other lives long and short will be entwined into the struggle to find Big Picture answers in the warm earth and the cold silence of space.

In 2011 two golden orb-weaving spiders preceded Nefertiti on the International Space Station, delivered via shuttle Endeavour in its last flight, and put in more than two months in another web-building experiment. Only one survived the return trip, and it obliquely offered aspiring scientists and teachers a lesson in humility.

Details matter in science and spaceflight, often to a poignant degree. The students, amid their extremely detailed preparations, had named this arachnaut Gladys. Back on earth, she was determined to be a he.

Henceforth the returned traveler was called Gladstone.

 

 
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Posted by on December 6, 2012 in Salticidae (jumping spiders), Spider science

 

Hot town, spiders in the city

31 Aug

Back of my porch getting dirty and gritty

You certainly haven’t seen this book. What fun for a reviewer! No need to outshout the bloggers and Amazon reviewers and all the other avid readers with too much time on their hands. No fear of spoilers, either. You already know how it comes out: the spiders defeat Voldemort.

The widow, the recluse, daddy long-legs … that’s life in the big city. Kinda like Sesame Street, only behind Oscar’s trash can and underneath Big Bird’s nest. But it’s home.

The pest-control industry seems to be putting a welcome emphasis on science, not a theme always in evidence when you read spider tales – often from out-of-the-way places – quoting pest assassins who have only a slender grasp on spider identification or envenomation.The book is published by Pest Control Technology, a magazine I do not see on the newsracks. PCT is also part of a company that offers products, training, and news that I assume is eagerly consumed by the pest-control industry. (It’s not too late to attend the pestworld2012 experience in October! Come to Boston for the beans, stay for the bugs. Seriously, I want to attend that conference’s brand-new Pest Academy. A certified pest as a child, I crave further recognition.)

Now the book: handsomely illustrated, with many color plates and B&W photos, and carefully laid out to make identifying common spiders almost effortless. Because it’s meant for pest-control people, it ends each chapter with information about how to get rid of spiders. I’m kind of OK with that, even for the harmless ones. Why? Partly because the authors have done such a good job of deflating fears of venomous lesions and other bugaboos, and partly because they coach the pest professionals on simple, non-genocidal methods of spider removal.

Typical of the tone in a chapter on small weaving spiders: “These spiders are far too small to cause any medical damage whatsoever.” What more needs to be said?

The pest controller is advised that the weaving spiders do make unsightly webs, which create scuzz around porch lights and eaves. Fair enough. So knock them down with a broom, the book says, install sealing and weatherstripping, switch to yellow light bulbs to discourage the bugs the spiders eat, and slap on the pesticide if you must. The chemical part comes at the very end, with the obvious implication that if you scrub up the outside of your house like the stereotypical Dutch housewife you probably won’t need to spray anything at all.

Meanwhile, there are tips about identifying the spider, including body form, coloration, and eye pattern. And further discouraging any rampant poisoning (at least to my sympathetic eye), the authors include tidbits about behavior:

The flatmesh weavers run quickly and randomly as if they have no idea where they are going. However, if they run into an ant, they immediately switch from frantic, unorganized movement to running tight circles around the ant, laying down silk and tying the ant to the ground. Sometimes, they reverse direction and make circles the other way to ensure the ant doesn’t escape.

Aw. It’s hard to take a flamethrower to a spider after you read a vignette like that. Just a dizzy little animal – no idea where it’s going – doing its Lucille Ball thing and it bumps into an ant, so it goes all dust devil on it while the ant goes Wot th’? and then it ties it up with its fuzzy cribellate silk (“like skeins of yarn from a craft store,” add the authors) and it’s one less annoying Hymenopertid at your picnic. Ha, get out of town, you little maniac – and take your egg sacs with you. Pesticide all over my house? I don’t think so.

Rereading the book I notice that the pest control advice, though useful and refreshingly calm, isn’t the best part. It’s the information about identification, morphology, and medical risks. This little handbook is a veritable short course in spider biology. And a great refutation of myths, especially about the purported dangers caused by spiders. I give it four spinnerets up (there doesn’t appear to be a WordPress icon for that). Buy a curious child a copy and maybe you’ll foster a memorable book report or science-fair project.

 

 
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Posted by on August 31, 2012 in Envenomation, Myths and Calumnies, Spider science

 

Put down the comic books. This is science

17 May

Huffington Post, how do I hate thee? Let me count the ways … OK, just one for now. But it’s a big one. It’s your “coverage” of science. Sciiiience. You know—the topic that has to be reported really carefully, and where you really have to get the words right, and it can’t be goosed up by inaccurate headlines?

“Tarantula silk could shoot from spider’s feet like Spiderman, scientists say,” brays the headline. But they don’t. And it doesn’t. And the initial tease—that silk can be extruded from a spider’s foot—appeared more than a year ago, to be followed by a couple of thundering rebuttals by heavyweight spider anatomists who had studied and published for decades. And even the first story didn’t say silk could “shoot” anywhere, only that it could be dabbed here and there to help a big spider keep its footing in a precarious place.

That’s a cool thing to explore. Evolution may have equipped ancient spiders with different silk capabilities than they have now. But the hypothesis that tarantulas employ silk-producing “spigots” amongst their toes has already been elegantly rebutted in the Journal of Experimental Biology, the place where the first paper appeared. The scientists challenged the hypothesis by covering the tarantulas’ spinnerets, the organs at the tip of the abdomen that are the only known places where a spider secretes silk, with wax. Traces of silk on the feet vanished. Ergo, the silken slippers had come from the spinnerets all along.

Some of the sensory organs of a solifugid, or "camel spider" (an arachnid but not in fact a spider). ©Journal of Arachnology

I’m just an amateur, but even I’ve read enough about spider morphology to recognize the structures that this correspondent had never seen before, these purported spigots. They’re chemoreceptors of some kind. The esteemed spider researcher Rainer Foelix, one of the aforementioned heavyweights, is the godfather of the spider textbook (yes, quite a specialized field). His works are filled with astonishing electron micrograph images of such structures, which look like a long, slender thorn or hair with an opening at the end. Spiders’ bodies are covered with thousands of these tiny biological instruments, along with others even stranger, with names like slit sensilla and lyriform organs. They form a neural network that tells the animal about its orientation, the position of its limbs, the physical load on its body, and its environment. The purpose of some of them is mysterious. These organs are the reason that an animal that is essentially blind, despite its abundance of eyes, can maintain such a sophisticated understanding of its surroundings: prey, moisture, dangers, weather, mating opportunities.

These are deep wonders, part of the reason I appreciate spiders so much. What we see from our human heights is a small, obscure being, going about its business with a stony disregard for us (oh, except for its lying awake at night, plotting to bite innocent schoolchildren, but that’s just insomnia. They don’t have late-night TV or Ambien). Of all animals they may be the ones most often seen through a glass darkly. But the view from a book like “A Spider’s World: Senses and Behavior,” by arachnologist Friedrich Barth, is vivid and literally otherworldly.

(Barth, by the way, works extensively with Cupiennius salei, a chunky tropical spider that sometimes hitchhikes in fruit shipments and is often accused of being Phoneutria fera, a much scarier individual. Cupiennius isn’t big and bad, it’s just big. But watch how fast a British grocer can scream that he’s found “the world’s deadliest spider” lurking in the bananas! It’s probably poor Cupiennius, chilled to the spinnerets.)

Foelix and Barth explore the wonders—not just anatomy but spider behavior, another planet alien to us—and lead science forward micron by micron. These books are never easy reading, and much of the science is beyond me (sometimes I just look at the pictures), but ultimately the diligent arachnologists run with the Carl Sagan pack, the Stephen Jay Goulds, who stress that wonder is out there. Not found by stretching human understanding and schemata over the universe like some sort of shabby cloak, but by letting these alien worlds of stars and animals and physics press their stories on us, and on our philosophies and gods.

So HuffPo, you shabby cloak, stop treating science like some throwaway bulletin about what the Hollywood hormones did today. Don’t you want another Pulitzer? You got the first one by nailing a story, getting it right the old-fashioned way. You won’t get another by spotting Spider-Man in the bananas. Don’t make Cupiennius come over there and bite you.

 

 
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Posted by on May 17, 2012 in Myths and Calumnies, Spider science, Tarantulas

 

Meet the spider: Cyclosa conica

13 Apr

The little hoarder

Not even the wussiest spider hater should hate wee Cyclosa. This one is twice hidden from fearful eyes: first, because she’s nothing but a crumb in the garden, smaller than small (6mm). Second, because she puts herself in an unobtrusive web that she’s filled with junk, and hides therein. She’s a disguise spider and an artist who works with found materials. Humble, too: no impersonating of hornets or ants, no lurking inside a tunnel and then thundering out, nothing vivid or glossy. If she’s around, the only clue might be a grimy bit of silk connecting a plant and its pot. The miniature hunter hides there, in all her trashy glory, awaiting even tinier prey.

Nope. Nooooobody here. Just us dust bunnies and random specks.

I cross paths with Cyclosa rarely, usually when she’s set up shop below the leaves of a container plant I’ve placed at eye level. Walking by, I glance at the shrub to see how it’s doing, and notice this six-inch line that looks like a strand of Christmas-tree tinsel, if you decorated with burrito wrappers and empty water bottles and apple cores. Upon closer inspection it reveals itself to be a dun-colored spider, her abdomen a tiny seashell, her legs all bunched around her face as if caught mid-peekaboo, waiting among a collection of dead bugs and other debris. For a long time I thought this web was just lint or dog hair or some other kind of yard snot.

Haven’t looked closely enough to see whether she’s Cyclosa conica, a cosmopolitan species well established in the Northern Hemisphere, or Cyclosa turbinata, also seen in this part of the Bay Area. It takes a very practiced eye to tell them apart, a familiar problem in spider-watching. Conica and turbinata are both pretty much the same name, ’scuse my weak Latin: cone-shaped. In lurk mode therefore they look like miniature hermit crabs.

Cyclosas are pocket-sized members of the orb weaver family, the esteemed clan that includes those graceful, gumdrop-shaped beauties with the huge, circular nighttime webs no one likes to walk into. Cyclosa means the turning spider, a name she somehow copped from her more magnificent relatives and hoarded to herself. Such are naming conventions. But the works of Cyclosa do have the same sophistication, writ small, as those of her big relations. Her little clothesline of dirty laundry is part of a larger, less obvious wheel, built from multiple types of silk that catch insect prey and signal the spider to come running. Like all web-building spiders she sits and listens with her body to the vibrations that come her way, pivoting toward movement, plucking lines to see if it’s something worth charging out of concealment for, attacking and subduing and swaddling the prey if so.

Humans try to plumb the reasoning of little animals that aren’t even aware of themselves. The motives of Cyclosa and other relatives that decorate their webs with objects, zigzag silken lines, even what appear to be writing (“SOME PIG”) are surprisingly hard to pin down. Spider researchers argue about this. What combination of attraction and repulsion do the decorations perform? Ponder the fact that at least one kind of Cyclosa, this one observed on an island off the coast of Taiwan, builds exact decoys of itself and its egg sacs. It attracts more predators than the standard-issue Cyclosa, yes, but it also fools them more reliably. Come and get me! taunts the clever hoarder. Yet she comes out ahead.

"Trash line spider"? I beg to differ. It's called recycling. (Rhithrogena22 photo; licensed under Creative Commons)

In true evolutionary fashion Cyclosa doesn’t need to know that the cluttered front yard where she leaves the dead husks is protecting her from birds, wasps, or annoyances like me. Her ancestors just had to have behaved as she does. And they passed on their genes for surviving amid a tiny pile of trash.

 

 
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Posted by on April 13, 2012 in Cyclosa (small orb weavers), Spider science

 

Always with the silk

04 Apr

But wouldn’t “The Spinnerets” be a great name for a band?

Comes more news of the wonders of spider silk. Writing about the magical silk is a cottage industry among news people and, it seems, scientists hunting for breakthroughs in materials science. This one researcher has managed, with the usual horrendous amount of effort (mostly on the spiders’ part) to collect enough silk to make a set of violin strings. The strings supposedly sing sweet and mellow, suggesting musical horizons yet to be explored, though no one has yet done the dastardly double-blind study that might disprove this claim, as double-blinds tend to do. Does the “Merry Widow Waltz” really sound different if played on the web of a genuine widow? Listen for yourself.

It’s too bad the silk didn’t come from a violin spider, the nickname for Loxosceles reclusa. Then we could rehabilitate the shy recluse a bit, balancing those gory photos of purported recluse bites you see on the Internet with more peaceful imagery, perhaps of Carnegie Hall or Yo-Yo Ma. Sure, I know the difference between a cello and a violin! The difference is many, many more spiders.

So while Paganini saws away in the background, let us contemplate silk. I saw some other news recently, about a scientist who reported that spider silk has wondrous properties of thermal conductivity, which could throw open the door to innovative insulation, clothing—who knows what. You already know the part about spider silk being “stronger than steel,” though Kevlar is really the fiber to beat (two guesses which would be easier to manufacture). And a few years back some folks wove shimmering golden cloth (below) from the work of more than a million unpaid, non-union golden orb weavers [Nephila inaurata madagascariensis] in Madagascar, who were last seen holding four protest signs apiece (leaving four legs for walking the picket line), Occupying a dusty corner of a museum, and demanding a press conference.

"Ewwwwww!" said the model, five seconds after this photo was taken.

But I want to ponder why there are so many stories about silk at all. You might say because of its commercial potential. Sure, the natural world is full of potential market blockbusters, some of them also humble and easy to find (like aspirin, distilled from tree  bark). Yet this evades the point that at some point in our dim, money-grubbing, lair-lining past, we started looking at animals and plants as things to be used not just in the immediate sense (club the foe with that tree limb and tie him up with this boa) but in the questing sense. Now they all have potential. Living things are made of parts and products. If we just ferret them out and sift them in the lab and have a really productive working lunch with the marketing department, that potential turns into cash and other good things.

I wouldn’t disparage that urge even if I could. No one has less romance for cave-living and/or whistling through the dark alley of microbial predators. Nasty, brutish, and short are my idea for the names of pit bulls, not a description of the life I’d like to lead. What I do disparage is the myopia that comes with a rigidly commercial view. Spiders get it pretty bad, and partly this is why. Their only redeeming feature, from the find-it-and-squish-it crowd, is that they might be coaxed into squirting out something valuable, little cash registers on the cobweb. I can’t count the number of times well-meaning people (and some not so well-meaning) have suggested that spiders not be flattened “because they eat bugs.” Bless you, bless you, lords of the earth, for giving this ’umble arachnid a reason to exist!

Milked, bilked, and de-silked. Where's Woody Guthrie when you need him? (Bernard Gagnon photo; licensed under Creative Commons)

With that in mind, I confess to satisfaction when these blue-sky lab products fail to come to pass. Reports usually dribble off into a comment about how tough it would be to scale up a spider’s work. Ha and yes! Rube Goldberg himself would be hard-pressed to invent a spider sweatshop like the one that imprisoned the golden orb weavers (right) in their little satanic mill (listen! They’re singing “We shall overcome,” with violin accompaniment).

The only success in that vein I’ve read about is the scientists who transferred a spider-silk-making gene into a goat, persuading the goat to secrete silklike proteins in its milk. That might work out, though I observe that it involves transferring a useful spider property into another organism rather than harnessing a spider itself. Transgenic can do that. Nature is more stubborn. How disappointing, then, that these unwelcome animals are so indifferent to redeeming themselves through the marketplace. (And apparently even the “spider goat” investors have gone udders-up.)

Keep an eye out for that binary status when spider stories cross your path. The terror and confusion over spiders as a creature will often peg the fear-o-meter (especially among ye excitable Brits). Then the scientific crowd will amble in with the earnest hope that if you all can keep from napalming every spider you see, we’ll be able to at least make a little money out of them.

Nobody has to defend ponies as worthwhile animals in their own right, or sloths, or otters. Especially otters, good god, wish I’d locked up the tchotchke patent on otters when sailors still thought of them as floating rats … The web-of-life murmuring comes easy for the pretty ones you can turn into turquoise T-shirts and trinkets, doesn’t it? But spiders—give a spider its due today. Admit that he or she has a life worth living for its own sake—or because it’s a graceful big branch on the Tree of Life, a success story tens of millions of years in the making, or even, if you really must be so damn reductive, because it can make mincemeat out of those mosquitoes and flies that bug you so much. That, at least, is a job fit for a spider.

* * *

Now, this I like. They’re trying to crack the chemical code for spider venom. What a funny headline: “Spider venom to be tested for pesticide potential.” Like saying, “Wheat has potential to be food.”

 

 
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Posted by on April 4, 2012 in Spider science

 
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