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Category Archives: Species

I’m being stalked by a jumping spider

14 Jun

Man in black

Three times in a year this audacious spider—hey, that’s its actual common name, the audacious jumping spider—has leaped into my life. Not the same actual spider, but different individuals of the species Phidippus audax in different places.

“Every breath you take … every move you make …” Sting, you say? No, but I can bite.

One even posed for some surprisingly good (if fuzzy) close-ups in which it appeared to have been preening its handsome, hairy self in the reflection of my iPhone.

I don’t remember ever seeing this species until a year ago, despite a lifetime spent in its range. Then, last summer, my daughter was planting trees and texted me a blurry snap of a spider her fellow planters thought was worrisome. It was loitering on a tree trunk with a grasshopper it had caught. A quick check with Professor Internet suggested Phidippus audax, and I told her there was nothing to be concerned about, unless you were a grasshopper. That’s me, spider tech support.

Just trying to blend in with the toddler outfits. What? It’s SoCal. We shop.

And then there was the children’s section of this precious twee earthy gift shop we were visiting in Costa Mesa a few weeks ago. The specimen you see in my photos was hanging out amid some pastel-colored little frocks, as I recall. Bold, indeed! Borderline pervy. Resisting my efforts to catch it on an envelope, it sidled into a box holding a hot-chocolate mug. Thankfully, no haters were about, nor fierce warrior moms. When I tipped the spider out of the box, it hung on with a dragline, giving me time to walk it to the door and let it land in the bushes. The clerks said they appreciated my green gesture, though they kept their distance and emitted faint screams.

A mere day later, my daughter and I were touring the restored wetlands at Bolsa Chica Beach, feeling fine to see how nice were the marshes and chaparral at what my family used to call Tin Can Beach. At the visitor center, housed in a biggish trailer, we saw the usual pickled and stuffed marine specimens and blowsy dioramas you’d expect at a site where the budget all goes to land acquisition, not fancy displays. But lo: in the corner of a plastic terrarium, a huddled black blob that looked strangely familiar. The young docents didn’t know what it was.

My cue! Out came the phone, I called up these photos, and asked, “Does it look like … THIS?” And how much better does it get than having a big, clear picture of the very jumping spider in question, right there at the ready? It doesn’t. It was like that scene in “Annie Hall” where Woody Allen drags Marshall McLuhan out from behind a potted plant to explain a Marshall McLuhan concept. Now the audacity was all mine.

Lots of spiders are soft of hue and hard to tell apart. Not this guy. Jet black with white highlights, built like a car, and often displaying shimmering green jaws. Not huge, but it has a presence: it might be the size of a quarter, legs included. I don’t know if it’s “audacious” because of its bold outfit or its bold habits. Either works. It prowls instead of lurking, so you’re apt to see it walking around in its stop-start manner wherever there might be prey. Two big, soulful, catlike main eyes, like all jumping spiders. At mating time, the males drum and dance and carry on. Don’t we all.

 
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Posted by on June 14, 2012 in Salticidae (jumping spiders)

 

Swatting down the angry spiders of Assam

08 Jun

Three and even more cheers for the level-headed journalists of India! who took that crazy spider story in Assam and dragged it into the cold light of day. You might have read those tales about big, huge, ENORMOUS dark-colored spiders being spotted in large numbers where they hadn’t before. Biting people, disrespecting cultural festivals, sending a few people to an early grave. First stories indicated they were giant (photos indicate otherwise) or called them “tarantulas” (again, photos are unclear), and cooked up a stew of overreaction seasoned with muddy facts.

No U.S. news outlets parachuted into the spider zone, so who knows what the arachnids would have done when confronted by Anderson Cooper and his accusing baby blues. So all we heard at first from this remove were tales from an echo chamber. Given the way these stories usually play out, how delightful to see how aggressively the Indian media smacked down the misinformation:

No evidence of spider swarms. Two people who died were swiftly cremated and evidence indicates one was bitten by a snake, and the other might have had an adverse reaction to the folk treatment inflicted on him. Arachnologists identified the supposed baddy as a common enough spider, not medically significant. The government even handed out pamphlets urging people not to panic, and pointing out that any “aggressiveness” on the spiders’ part was probably due to their being more noticeable at breeding time while on their nuptial stroll. A handful of people reliably reported as suffering spider bites (“I picked it up,” one admitted to the camera) were simply treated and released.

I liked the coverage on one website dedicated to covering “the marginalized areas of India.” TwoCircles.net pointed out that frightened people were killing spiders on sight, which was likely to harm the ecosystem. That’s a germane point your average breathless rumormonger rarely makes. Wipe out spiders and you’ll give free rein to crop pests, malaria-carrying mosquitoes, and who knows what other invertebrates and nasties.

(That site wants to be a “voice of sanity” for regions where good reporting is hard to find. Not perfectly objective or comprehensive, but a source of reliable information for intelligent decision-making. Wow. Missed the Web 2.0 version of online news in a big way, didn’t they?)

The India spider panic began more than a month ago, and I’d call it a Rorschach test for spider phobia if the term “Rorschach test for . . .” weren’t so overused and abused. (Same with “tabula rasa.”) Let’s just call it a great example of how spider fear can amplify and twist stories, and keep skepticism at arm’s length because when you’re talking about spiders, of course they’d do exactly that, wouldn’t they? The Times of India, which unlike its compatriots did not acquit itself well, even used the phrase “eight-legged freaks.”

And, oh god. One guy thinks spider swarms mean Gaia is fighting back. A blogger on NPR confidently asserted: “Assram state doesn’t have any poisonous spiders.” Uh, Assram? No venomous spiders? What do the spiders of Assam inject, Sunny Delight?

The crack news team at the Long Island Press illustrated their story with a picture of a fake spider from the “Harry Potter and the Chamber of Secrets” movie. Note to crack news team: spiders don’t scowl.

Meanwhile, HuffPo thinks there are vampire spiders.

Mamma mia, if it's-a not-a one-a stereotype, it's another! Whattaya gonna do.(Lycosa tarantula photo © J. Coelho, Creative Commons)

Spider hysteria has been kind of quiet lately. The Assam story echoes the folk fears that inspired the tarantella, the dance craze based on the belief that one had to boogie down and shimmy out the venom of the field spider that inspired the word “tarantula” (the spiders of Taranto, Italy, were probably not tarantulas but wolf spiders). I bet the tarantella has launched a thousand dissertations about medicine, mental health, and bacchanalian behavior. I only note that a spider—not an ant, not a bee, not a beetle, not even a rabid dog—kindled such a strange belief. Ancient or medieval or modern, people are always quick to tremble over the small dangers presented by spiders, even when they should be worrying about the large dangers of MRSA or viruses or much bigger animals with much bigger teeth. Or, if you live in Assam, cobras.

Also I think of those cohorts of schoolkids (typically girls) who develop strange speech patterns or tics or bruises en masse, blaming a purported toxic dump or a funny smell or a locally defamed creepy animal, only to miraculously recover. Watch for a fifth-grade class somewhere to be pursued by an army of recluses with a sudden appetite for ankles. And squeeeee! . . . off they go.

The Assam spiders surely were there all along, minding their own business in the woods and fields, until somebody trod on a few burrows or tipped over the wrong hollow log. Poke ’em with a stick and they display “aggressive behavior” toward the huge mammal that can crush out their life. Wouldn’t you?

 

 
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Posted by on June 8, 2012 in Envenomation, Myths and Calumnies, Netlore, Tarantulas

 

Meet the spider: Steatoda grossa

27 May

Spider-Man, I made you!

It’s almost summer, and that means superheroes. A torrent of them, a plague of them! Not unlike the grim spider army that homeowners report to their local newscasters whenever they see something brown that skitters. This time there’s a big hairy blockbuster movie among the big hairy intruders: “The Amazing Spider-Man.” I’m not a comic book fan, so all this talk about a “reboot” leaves me cold (spiders, the real kind, shiver when you say “boot.”). It opens July 3, so I might as well let my online searches overflow with Andrew Garfield this, Emma Stone that, not to mention “Turn off the Dark” (the Broadway show), until the wires go back to their usual chatter about Invisible Spiders that stalk the unwary sleeper.

Still, I must take note of one rumored change in the Spider-Man backstory. You might recall that one character prominent in the Tobey Maguire version of the “Spider-Man” franchise was a spider. It bit Tobey and made him what he is. Apparently the spider was radioactive, which is one of those fun, wacky 1950s conceits that don’t really scan today … radioactivity leading in fact to death, not superpowers. At the start of that first film, which I saw in pursuit of a Big Dumb Summer Movie, the spider landed on Peter Parker and nipped him. The bite was just Method acting, but the spider was real. It was even wearing spider makeup and carrying a tiny Equity card. The actor was, however, false: a false black widow, or Steatoda grossa.

Fanboy rumor says this year’s Peter Parker gets endowed not by a radioactive spider bite but by something from a lab … genetic tinkering or some such. And I bet they don’t even use a live spider this time, computer graphics having progressed so far. Dang. One more out-of-work actor, and in this economy. Guess it’s back to the back lot for Steatoda grossa, which is probably where the spider wrangler for the 2002 movie found her in the first place.

This common species occupies the margin between medically significant spiders and the innocent, ain’t-hurt-nobody garden varieties. Steatoda grossa practically defines garden variety. The places she likes to live are all over the typical yard (basement, too). She hides under the terra cotta saucer, in the space between shed and fence, in a sawdusty nook by the car, perhaps in the finger of your garden glove—pretty much anywhere you might expect to see a black widow (Latrodectus), except she isn’t one. False widows seem to favor damper places than the true widow, such as the crawlspace under my house where moisture from the clothes drier lingers. Real widows, like Marilyn, like it hot. When I catch Steatoda she usually plays dead, which makes me feel bad, so I let her go, then she ever-so-slowly unshrivels and stumbles away.

Without her makeup on, but still ready for her closeup. (Univ. of Wisconsin, Dept. of Entomology)

Her coloration is variable but the ones I see most often are glossy dark brown with a pale dot or two on her dimpled abdomen. She (or her male counterpart) might be marbled like halvah. If you look close you see she has oddly glittering eyes, gleaming with Hollywood ambition. The posterior median ones, I think. They sparkle like flecks of glass in the flashlight beam—and not just from the front, like the usual spider eyeshine. (You don’t know about eyeshine?! One of the wonders of spider watching. More on that later, if I can get decent pictures.)

It’s funny how many people think any old brown spider is a recluse, but I can’t blame people for thinking Steatoda is a black widow; they are relatives, after all, in the big happy Theridiid family, and favor the same look and the same turf.

In Britain they go all barmy over a cousin called Steatoda nobilis, a mildly medically significant non-native creature that’s got everyone’s rugby shorts in a bunch. “The most venomous spider in Britain!” Oi, you’d think it was the Blitz. And most of the tabloid cases quote Wallace or Gromit saying, you guessed it, “Never saw the little bugger who bit me,” and even the visible buggers are usually identified by the nearest Cockney chimneysweep and not by anyone who’d actually know. Still, there are a few confirmed Steatoda bites here and there. This isn’t one of them (hint: Steatoda nobilis, like Peter Parker, lacks the power of invisibility).

Fun fact! Scarlett Johansson is neither black, nor a widow. She is actually a divorcee.

After Steatoda grossa had her big moment in “Spider-Man,” lots of people were surprised to learn that the spider wasn’t computer-generated. An insect wrangler had supplied the false black widow and dolled her up in red and blue to make her look sinister. Although Steatoda has the right figure for the part (sleek, glossy, tapering, and can I mention Scarlett Johansson as the Black Widow here? No? Aw), she can’t do radioactive without having some work done. National Geographic ran a fun story about the bug boss who cast Steatoda for her big part.

You can induce Steatoda grossa to bite you, not that I have, using the technique of rolling over on her or trapping her in clothing. I’ve never found any indications that the bite is worse than a bee sting. This is the usual pain yardstick that’s meant to reassure people but kinda doesn’t, given how much we all enjoy being stung by bees. Reported symptoms include “blistering” and “malaise.” Once in a blue moon a bite creates significant medical problems, and at least one study has shown that antivenin developed for bites of the redback spider (Australia’s native widow) works for Steatoda as well. But you takes your chances: people have fatal anaphylactic reactions to antivenin, too.

The false widow is neither hero nor villain in her contacts with the human world, falling into the category of small animals that should be acknowledged but not feared. As with most spiders it’s quite obvious what kind of business she’s about: not stalking people (although do shake those garden gloves) or pursuing evildoers, but rather pursuing bugs for dinner, spinning her sloppy yet effective web, lying low, making more of her kind.

She doesn’t have any superpowers, and I do wonder why her bite made Peter Parker shoot silk out of his … wrists. Is the moviegoing public not ready for an anatomically correct Spider-Man? Bet Howard Stern could have fun with that.

Some relatives of the false black widow do have special talents beyond scaring British people. They can live together without killing each other. These are among the social spiders—like social butterflies, I guess, but with fangs and venom. Life in the spider colony is sure lively, what with prey-capture cooperation, shared egg-sitting, and occasional mass emigration. How they work it out is a mystery, though the uncommonness of this arrangement suggests to some scientists that pallin’ around with your fellow cannibals might not be the best idea for spiders in the long run.

As for long runs, let us prepare for a summer of super spiders and bats and men in black, leading perhaps to new impressions in the Hollywood Walk of Fame, though if there’s a spider there in the concrete you can guarantee it was stepped on. Fame is the ultimate false mistress, poor Steatoda grossa.

 

 
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Posted by on May 27, 2012 in Envenomation, Myths and Calumnies, Netlore, Steatoda (false widows)

 

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: Pholcidae

20 Apr

We three Dads

The cellar spider has a wonderful gothic, childlike, shivery myth attached to it. Have you heard? Omigod, the daddy long-legs has the most poisonous venom ever discovered! but, like, its little fangs can’t penetrate human skin so nobody even knows, so you could be totally killed by it, but nobody ever is.

This wacky idea actually seems to be dying out, even among the swaggering schoolchildren who answer most Internet queries. “Mythbusters” got around to addressing it a while back (yes, Adam got bit. No, he didn’t die. Maybe he exaggerated a bit about the bite, which he didn’t even show, but how long can a camera show nothing happening?). It probably takes a hit Discovery program to begin to turn the tide of Internet nonsense, especially when it comes to such a durable and colorful tale.

The cellar spider, one of several dudes dubbed “daddy,” looks like something made out of mini-marshmallows and pipe cleaners. A spindly, fragile thing that offers the most florid display of timidity in nature: if you touch its web, it trembles. Think of that, you “Lord of the Flies” schoolkids with your misspelled boasts about pulling off its legs, one at a time. It just shivers and waits for you to go away.

Who’s your daddy, long-legs? Now about that name. You have to brush past the stiff angry online Commenters who shout that the daddy long-legs is NOT a spider or else the daddy long-legs is TOO a poizinus spider and one bit my cusin and her elbo fell off and get to the place where it’s clear that “daddy long-legs” means three different animals:

 

GOOD VIBRATIONS: a cellar spider.

1. A spider. Two common species (very common, actually) of the family Pholcidae that live in my area are Pholcus phalangioides and Holocnemus pluchei, the latter known as the marbled cellar spider. Neither belongs here; they’re among those pushy Eurotrash species that arrived at some unknown time, eclipsing the native spiders. And they really like it here.

 

 

WALK ON BY: a harvestman.

 

2. An arachnid called a harvestman. Strange little striding bug, it looks like the invader vehicles you imagined the first time you read “War of the Worlds,” with a tiny gondola suspended at the vertex of eight immensely long, thin legs. Not a spider, not venomous. It eats everything in the garden but can’t bite you. Defends itself by making a funny smell.

 

 

COME FLY WITH ME: a crane fly.

3. A crane fly. California has more than 400 species of this bug, which turns from a grub in the ground to a flying insect. Harmless, though it resembles a giant mosquito. Scientists identify a larva by looking at its rear end, through which it breathes, and which is decorated with eye-popping, grotesque patterns that look like Mardi Gras masks (below). In my family we called crane flies gallinippers, a name I thought my own daddy made up because he has a knack for wordplay (big mosquito = gallon nipper), but I learned that not only is this a folk name, but “gallinipper” is also used for an actual huge bloodsucking mosquito and not just the innocent crane fly.

This is one crane fly’s southern exposure! Aw, I’m gonna have nightmares now. (Nephrotoma virescens illustration © Chen Young)

Also it’s a bluegrass band, one that proudly proclaims “The Gallinippers is on Facebook!” And so they is.

Also, there’s a silly poem:

. . . Then Mr. Daddy Long-legs

And Mr. Floppy Fly

Rushed downward to the foamy sea

With one sponge-taneous cry;

And there they found a little boat,

Whose sails were pink and gray;

And off they sailed among the waves,

Far, and far away.

(Edward Lear, “The Daddy Long-Legs and the Fly”)

The cellar spider is the dad I know well. It lives in a world of dim sunlight, sawdust, splinters, old storage smells. Your basement, attic, or garage. Or, if you’re casual about housecleaning, the no-dad’s-land behind a desk or sideboard or bookcase. The spider makes a messy web that it’s agreeable to sharing with fellow spiders, where they all hang upside-down, snagging flying bugs, vibrating like little cell phones when disturbed.

Even the pest-control folks, always eager to suggest ways of annihilating local fauna, have nothing bad to say about the cellar spider except that the webs are “unsightly.” It was still worth several people’s time to write about the best ways to keep those dirty dads under control, though (hint: vacuuming and judicious use of pesticide).

The only thing I dislike about Daddy is that he poops in corners. Any nook occupied by a cellar spider is going to have dark-and-light spatters on the floor or shelf below. It’s not the easiest of spooges to clean up, either, and it makes the surroundings look drear and grimy. The cellar spider, not the tarantula or widow, is the spider that should have the role of Halloween gloom-meister, since its presence indicates a place disused or abandoned or otherwise atmospheric. Otherwise it’s about as spooky as a kitten.

It’s not scary and (unlike a jumping spider) it can’t dance—in sharp contrast to Fred Astaire, title character of the silky 1955 musical “Daddy Long Legs.” Watch as the grand old hoofer ensnares young Leslie Caron in a web of dance, for which she is grateful and adorable and extremely French. Sweet story. It surprised me to learn how many versions of that film were made in the last century, with different actors as the daddy. Sometimes the leggy leading man—harmless, never venomous—snares Mary Pickford, sometimes Janet Gaynor, once an anime orphan, once even (gasp) Shirley Temple, though in that version (“Curly Top,” 1935) Daddy does the nuptial dance with the moppet’s grown-up sister, not Shirley (*whew*).

What do those old movies have to do with cellar spiders? Nothing, though for once it’s nice to associate a spider with a silly fable not having to do with gangrene. And by the way, I’d take Leslie Caron (“Daddy Long Legs”) over Theresa Russell (“The Black Widow”) any day.

 

 
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Posted by on April 20, 2012 in Envenomation, Myths and Calumnies, Netlore, Pholcidae (cellar spiders)

 

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

 

Meet the spider: Latrodectus hesperus

28 Mar

Ladies of the night

The widow tends her parlor.

I don’t worry about the widows. They’ll be fine. Putting aside the question of whether I should be worrying about them, I know they’re a resourceful bunch. Ever since the first bulbous lady of the night appeared along the property-line fence, spinning her tough, ratty web as I walked past with the flashlight on garbage night, the black widows have endured. Now that the builders next door are about to demolish the fence and build a new one, it’s very likely that the widows will just colonize that one, too. I won’t bring it up with the new neighbors, at least not right away. They’ll think my sympathies are misplaced.

The widows who haunt the fence haven’t been there long. When we bought the house 11 years ago most of the spiders in the nooks and crannies of the yard were Steatoda grossa, false black widows. They scare the unwary, because they’re petite, dark-chocolate replicas of the widows and they hang out where you’d expect a widow to be. After a little research and a lot of familiarity I saw them as chums, and now salute the false widows as they fumble away from the broom. But then Latrodectus appeared—not actually glistening in the light of the full moon, though that enhances my mental picture—and suddenly Steatoda grew scarce. This new species bore watching.

I thought about wiping them all out before they got too entrenched, but never had the heart. I caught and relocated a few. I kept a couple others in terraria out of curiosity, but when they spun egg sacs I questioned the wisdom of the project and relocated them, too. And now they’re part of the landscape: invisible by day, out on their lines by night, always ready to scoot back into a downspout or between the slats if they detect something amiss.

And that’s why, I think, I let them be. The western black widow and her more notorious Theridiid relatives are nothing to mess with. I won’t dandle them or coo at them. But nor are they coming to get me and my children. Having tried many times to catch them, I tell you it’s not easy: they’re wary and will retreat from the slightest suspicious vibration. Even if I plowed through their triplines while taking out the trash, they wouldn’t charge me; rather, they’d do their clumsy best to sprint back to safety. It would take me jamming a finger into their lair or picking one up with my bare hands to get bitten.

By now, the widows are like neighbors. The ones who don’t keep up their yard, whose taste in Christmas decorations runs to the tacky, who got the F-150 on blocks in the driveway, sit on the porch in the evenings, don’t make eye contact. They probably keep a handgun in the nightstand. It’s enough to know their name; no need to be overfriendly. Still—it’s their neighborhood, too. If they go away of their own accord I’ll be relieved, but in the meantime I don’t feel threatened.

The black widow is a medically significant spider, no doubt. The human body’s response to her neurotoxic venom is called latrodectism, something I don’t want to experience. (You know you’re famous when somebody names a whole disease after you: benign Linsanity, deadly Snookiism.) Latrodectism is an agony of clenching muscle pains, often with nausea, headache, copious sweating, and accelerated heartbeat. Medical sources repeat like a mantra: death is rare, although risks are higher for children, the elderly, and people with compromised cardiovascular systems. Antivenin works but usually isn’t necessary, and it can make things worse.

The widow isn’t “lethal,” forget what the Internet says. I sought a hard number for this, not the moldering Netlore people toss back and forth. Here: the latest report of the American Association of Poison Control Centers (AAPCS) tallied 2,168 widow spider bites in the US in a year. No one died from them. Even if you added in the 3,345 “unknown spider/insect” bites (including my pal the Invisible Spider and anything else that crawls, visibly or not, across the national epidermis) … still zero deaths. Only 13 widow cases were even considered major. The largest category of outcome: “minor.”

Now, there is that “Case 1259,” the middle-aged asthmatic hospitalized for a black widow bite. Thirty-six hours later, he’s dead—but of anaphylactic shock. Triggered by the antivenin itself, not the bite.

Bee/hornet/wasp stings were three times as numerous as spider bites—with two fatalities. Other villains:

  • Car antifreeze, seven deaths
  • Toilet-bowl cleaners, three
  • Hearing-aid batteries, two
  • Liquid laundry detergent, two
  • Good ol’ “ethanol (beverages),” a raucous twenty-one.

(Interestingly, the report cites a single death from “other spider bites and/or envenomations,” but since widows, recluses, and Invisible Spiders were already tallied separately, it’s a mystery. Perhaps it’s the unfortunate Case 1259.)

Another report, from 2005, explored animal dangers to humans and calculated an average of six deaths from venomous spider bites every year in the United States. Curiously, it found almost as many deaths from “non-venomous arthropods,” and cited the anaphylaxis risk. And note: in this telling, hornets, bees, wasps, and ants were nine times as dangerous as spiders. (Curiouser still, isn’t it, how the AAPCS hasn’t found even one widow fatality since it began issuing annual reports in 1983?) Cows, horses, and mules go bad, too.

The widow’s reputation has clearly been besmirched. She isn’t always lethal even to her mate. It would make for a better episode of “Who the (Bleep) Did I Marry?” if she were, but the fact is lots of spiders are prone to husband-noshing, depending on hunger and other circumstances, and she’s not a standout.

The adult male widow is a skinny guy, with rather attractive marbling on his trim, brownish exoskeleton. (No one suspects him of being dangerous to humans, unlike his bride.) I see him lounging around the lady’s porch of an evening. Our widows get lots of gentleman callers.

And like another famous widow, Blanche DuBois, these femmes noires depend on the kindness of strangers. Me.

 

 
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Posted by on March 28, 2012 in Envenomation, Latrodectus (widows), Myths and Calumnies, Netlore

 

Meet the spider: Zoropsis spinimana

21 Mar

The new (big) kid in town

Zoro salutes you.

Hello. I am Zoro. Fear me—but wait, no, do not fear me. I am not the monster I seem. I am invasive, but I am not … how do you say … of medical significance.

Presenting Zoropsis spinimana, a newcomer. A big, impressive newcomer. I happen to live in a part of California where this Mediterranean import has established itself. Lucky me, you say? Well, yes. It’s a big, handsome spider, slow-moving and easy to catch, and someday I’ll figure out exactly what it’s finding to eat in my walls and ceilings and crawlspaces that can satisfy its clearly big appetite. In the meantime, whenever I see daring Zoro, scourge of the arachnophobe, poised high up on the wall, it’s like Halloween every day! Boo!

Zoro, as I like to call it, has been dubbed the Bay Area’s Most Wanted Spider. Sort of like the World’s Most Interesting Man, which must be why I mentally shifted into that Puss in Boots accent. Stay hungry, my frien’. At the California Academy of Sciences in San Francisco, which dubbed it “most wanted” in a bit of savvy publicity, they’ve been tracking the spread of Zoropsis since the hefty house spider was first spotted around here. It has a gorgeous website there, complete with photos, videos, a map, instructions for reporting a new location, even tips for mailing in a spider—dead or alive—for inspection. The downloadable data sheet says, “Body size is the first thing you will notice about this species.” Yes, yes you will. Two inches (legs included) doesn’t sound like much until your daughter sees it on the bathroom wall.

What’s odd on that Cal Academy site is a distribution map that shows a straight arrow going nonstop from the Mediterranean to what looks like Sunnyvale. How did that happen?

“Hiding inside a suitcase” is the site’s suggestion, but, of course, ha. That’s just a guess. Darrell Ubick is the Cal Academy spider expert who’s keeping an eye on Zoropsis and its travels since it showed up in these parts in 1992. Ubick identified the newcomer courtesy of a specimen sent him by a cherished “spider lady,” the late naturalist Marjorie Moody, who worked for the state agriculture department.

However Zoropsis got here, it’s in no hurry. The spider has been seen a few times as far north as Marin County, Ubick says, but most of the reports still come from here in the Santa Clara Valley. In general, globalization accounts for a lot of species transfer; more people and goods and luggage crossing borders, more numb Central American spiders huddled in bananas in British shopping carts. But the Mediterranean region isn’t exactly Mali, is it? Ships and then planes from Europe and north Africa have been docking in the Bay Area for a very long time now. Zoro must have a story to tell about its covert crossing of the border, but we may never know it.

Nosferatu, the original movie vampire. None of that "Twilight" eye candy back then.

Où est "le masque"? I shrug in the Gallic fashion. (Photo: Le Monde des Insectes 1999-2012)

Some spiders seem to trigger the imagination. This one is dashing Zoro to me. Now, French people who post macro pix of this spider get a little frisson by pointing out not the Mark of Zorro but “le masque de Nosfératu.” The supposed mask is a pattern of black on white on the cephalothorax that suggests a vampire face with black eyes and pointy ears. Can you see it? How French are you? I’ve tried really hard to see Nosferatu but alors, I cannot.

Heck with romance, I think Zoropsis looks like a guy in a garish brown herringbone suit. He’s built like a wolf spider who’s put on a few, but with proportionately smaller eyes. He has that interesting dark pattern on the upper side of the abdomen; that helps to identify him. He roams, like the wolf spider. Willy Loman, schlepping his big opisthosoma around the countryside, hunting for the big sale. What I’ve noticed from briefly keeping Zoropsis specimens is that they try to conceal themselves in a container by climbing to the top and then streamlining their legs, four forward and four aft. It’s kind of endearing, and it makes them look not so big. They also seem to be good-natured, although tickling one’s foreleg with a bit of straw might make it pause and draw back the leg in that melodramatic “Wha! What means this?” gesture that thoughtful spiders (and movie vampires) make. Other times it seems like a golden retriever compared to a wolf, by which I mean the wolf spider Hogna carolinensis. I’ve kept a few of those, too. They’re athletic and fast, big shiny button eyes, dove-gray tracksuit, and the way they dash about and pounce on crickets is a dramatic contrast to phlegmatic Zoro. But Zoropsis, even if flair-impaired in reality, must be doing something right. The distribution map of the greater Bay Area shows a healthy scattering of red dots. Zoro was here!

 

 
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Posted by on March 21, 2012 in Netlore, Zoropsis

 

A spider insider

20 Mar

Wayne Maddison is the jumping-spider man of the Internet. His courtship videos of Salticids are amazing and touching and hilarious just by themselves (what rollicking little Travoltas these jumping spiders be) but people in Netland have been setting them to music for ages, too. Salsa, disco, anything with a beat that seems suitable for flashy duds and the tricky wooing-slash-groveling that the male jumper indulges in. I’ve always wanted to meet Wayne Maddison. But not today, not just because he works in British Columbia but because according to his blog he’s off in Borneo, literally beating the bushes for undiscovered species and probably having a high old time. Here’s something he recently sent back. It’s a Salticid that looks as if it were made out of lemon hard candy. The thing to notice: you can see right through it, watching as those big telescope-like anterior median eyes sweep across their environment. This one is from Ecuador.

 

 
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Posted by on March 20, 2012 in Netlore, Salticidae (jumping spiders)

 

Calm down, arachnophobes

16 Mar

I couldn’t ask for a better poster spider for launch week. A fresh wave of worry about the brown recluse has just washed over the blogosphere, apparently because of a scary tale about a Texas woman bitten by a recluse who then posted lavishly gross pictures of her ailment online. This happened last year, not sure why it took so long to get about.

I’m going to write more about those reckless recluses. There are a lot of fascinating things about Loxosceles, some of them in the folkloric vein and some in the scientific (did you know the Binford Spider Lab in Portland, Oregon, focuses on the recluse and related species? All kinds of research coming out of there). But for today, I’ll point out with minimal comment how the words “brown recluse” trigger a most predictable response in humans, and I’m not talking about rotting flesh or horrible death. I’m talking about hyperventilation.

The Texas woman was bitten on the neck in one of the unusual cases where a spider (any spider) was actually caught in the act. Yes – most of the “spider bite” cases we hear about and read about involve a species (to be profiled later) I call Aranaeus invisibilis, the North American stealth spider, and no, I never learned Latin so please school me on a better name. A sore erupts; people blame a spider they never saw. I don’t trust news and blog reports of the Texas case far enough to know whether the spider was actually a recluse, though that is plausible, given their range. The original report suggests it was identified in the emergency room, which usually sets off some warning bells because few doctors can ID a spider on sight, and even when they’re mistaken their “spider bite” diagnosis is taken as holy writ. Loxoscelism is the actual term for a reaction to a recluse bite, but physicians chalking up a mystery sore to loxoscelism is like saying “I know it was a brown recluse because this is a brown recluse lesion.”

Penny for your thoughts?

But even if the Texas spider is provably a recluse, such necrotic bites are not common. No recluse bites are. Then there are dry bites (no venom), and non-symptomatic bites. And as for the spider being “deadly” … no. [Read all about it at the Burke Museum in Seattle, where Rod Crawford, curator of arachnids, takes on this myth.]

It’s laughably easy to post gory pictures on the Internet and say they came from a spider. People believe you immediately when you say it was a brown recluse, even if you acquired the wound hundreds of miles away from any recluse habitat. Even if it happened under circumstances (such as being in prison) that cry out for a more rational explanation, such as MRSA, or drug-resistant staph, which is far more dangerous than any spider. MRSA: now that’s an evil bug.

By the way, the Texas woman rapidly got better. The bloggers panting that the spider almost made her go blind – well, the bite caused one side of her face to swell up and close her eye for a while. There’s been nothing reported about any threat to her vision.

“Hyberbolic media crap!” pronounces the estimable spider expert Rick Vetter of UC Riverside, who’s talked himself hoarse trying to set the public straight on the recluse and other spiders. When such stories hit, reporters not too lazy to do a bit of research call up Vetter and get some bracing counter-quotes like this one. Everybody else just goes with the hysteria.

This story seems to have erupted in the Daily Mail in excitable Olde England, where spiders hardly ever get a break. It got an even bigger push when people dragged in a recent study suggesting that climate change is going to change the recluse’s distribution in the United States and then … radically misinterpreted that part, too! Shouts and alarums: the recluse is on the march! Coming to a gardening glove near you! When what the study said was that a warmish shift might … MIGHT … cause the recluse to spread north from its accustomed Midwest/Southeastern range but also to VANISH from parts of its existing range.

Oh. Where’s the fun in that? And the irony is that the public widely, devoutly believes that the brown recluse is already swarming across the country, biting coeds’ necks wherever it can find them. Heck, there’s that vampire slander again. That’s also cognitive dissonance, believing that 1. The recluse is spreading to new turf and 2. The spider is already everywhere in teeming masses. Just par for the course for Loxosceles reclusa.

 
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Posted by on March 16, 2012 in Envenomation, Loxosceles (recluses), Myths and Calumnies, Netlore

 
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