One night when Ed Tillinghast and his wife were settling into a motel room, he discovered that one of his spiders had escaped. And this was no ordinary spider.
The Tillinghasts were on one of innumerable trips they've taken over the years to collect specimens of Argiope aurantia, the striking black and yellow garden spider with an elbow-length black glove on each of its eight legs. They grow them big down South, and this one may well have measured 3 inches across, from tip to tip. Tillinghast wasn't concerned about the loss of the spider—nor was he worried that it would hurt anyone. Garden spiders rarely bite, and even if one did, its venom wouldn't be harmful, he says. He just didn't want to scare the hotel housekeeper to death.
After searching the room, Tillinghast finally gave up and went to bed. Then in the middle of the night, he awoke with a start. He could feel the light, tickling touch of the spider's feet as it crawled across his forehead. "Margaret!" he cried out in joy and relief. "I found it!"
Tillinghast, a professor emeritus of zoology who has studied spiders for more than 35 years, is full of similar tales, but he insists that he's really no different from you or me. "It's not any special quality I have," he says. "I often pick up Argiope with my bare hands because I know its behavior. I wouldn't think of picking up a tarantula."
He acknowledges that he had no fear of garden spiders—"candy spiders," his older brother Howie called them—when he first noticed them at age 8 on a Rhode Island farm. Their parents had separated before Ed turned 2, and he spent his childhood moving from foster home to foster home. No one could have imagined he would ever become a scientist, let alone one who would make significant contributions to the understanding of spiders and the industrial-strength fibers and glues they produce. Spiders ultimately became one of the joys of his life, nonetheless, and although he has studied black widows, brown recluses, barn spiders (of Charlotte's Web fame) and more, the garden spider remains his favorite.
A Breed Apart
"All my life, I've been interested in the damnedest things," says Tillinghast. Chicken blood. Earthworms. Spider saliva, silk and glue. The field of arachnology is a relatively small one, with no more than a thousand researchers worldwide—and, as a group, they're a rather odd species. Required for the job, it seems, is a certain quirkiness, a taste for black humor and a commitment to reason in the face of a subject that courts hysteria. For some, the quest leads to unorthodox, even masochistic, scientific methods.
Arachnologists, for example, have a long history of convincing spiders to bite them, often in an effort to prove the creatures harmless. In 1923, to determine if black widows were poisonous, zoologist W.J. Baerg was able to induce one to bite his finger and inject its venom for a full five seconds. Then he documented the widespread pain, hallucinations and respiratory effects that ensued. He was hospitalized for three days and took a week to recover. In his classes at the University of Arkansas, he would pass a tarantula around the room from hand to hand, to acquaint students with the hairy giant—and to build character. In 30 years, he noted, only one student was bitten. (A North American tarantula bite, experts say, is comparable to a bee sting.)
Tillinghast, a gentle white-haired man with an almost courtly manner, is hardly the type to force students to handle a tarantula. Still, his methods do sound like something out of a campy horror movie. He's been known to mechanically extract a spider's silk by winding it on a drill bit; he's coaxed spiders to drink radioactive cocktails and then fed the resulting webs to other spiders. Some scientists go so far as to "milk" the venom from tranquilized spiders while administering an electric shock. For brown recluse research, Tillinghast prefers a simpler approach—killing the spider, removing its fangs and extracting the venom. "I could show you how to do it easily," he says.
The Education of a Spider Man
When Tillinghast was 16, he and Howie returned to live with their mother, who convinced Howie to quit school and get a job and urged Ed to do the same. He resisted out of sheer obstinacy. "For all intents and purposes, I wasn't going to school," he says. "I was only sitting there." A year later he was invited to move in with a minister and his family. For reasons Tillinghast still can't explain, he experienced a kind of intellectual awakening and began reading every book he could lay his hands on.
Despite a weak high school record, Tillinghast was accepted at the University of Rhode Island with, he suspects, the minister's help behind the scenes. There, he took a shine to zoology and, in particular, earthworms. He eventually earned a doctorate in physiology at Duke. After joining the UNH faculty in 1967, he gravitated to his true calling—the study of the physiology of spiders. Before long he found himself in another intellectual renaissance. This time, it took the form of an explosion of ideas, questions to ask and puzzles to solve. One day in a cell biology lab, he was demonstrating how to test for proteins, fats and carbohydrates. Spider silk was believed to be made of pure protein at the time, but in a flash of insight, he wound a spider's web onto a glass rod and asked a graduate student, Edward Kavanagh '79G, to dip it into a chemical that tests for carbohydrates. When the web turned pinky red, the pair had discovered—in front of a class—that spider silk also contains carbohydrates.
The change in research interests also had a big impact on Tillinghast's soft-spoken wife, Margaret, who turned out to be an unflappable spider-hunting companion. "Fortunately, I'm not afraid of the things," she says, recalling the day when she found a tiny spider crawling up her leg on the way back from a Southern spider-collecting expedition. Soon there was another one crawling up her leg. And another and another. The couple pulled over and retrieved a plastic capsule holding a black widow's egg sac. The spiderlings had hatched unexpectedly and were emerging through the air hole in the container.
It is Tillinghast who gets a call—and gets to keep the spider—whenever a black widow has been found in the state of New Hampshire. All the black widows he's received so far have been of the Southern or Western species, and there's usually an explanation as to how they made it so far north—sometimes as a stowaway on grocery store grapes. (He ran an experiment with Southern black widows to see if they could survive the winter in an unheated building—they all died.)
Tillinghast, who has studied venom production in black widows and continues to study their silk, keeps his black widows in a Plexiglas structure he calls "the condominiums." In a corner of each cell, a female clings to her messy little web upside down, with the familiar red hourglass visible from above. Her abdomen is almost spherical, and as shiny as patent leather. Although her body is only about half an inch long, she has a bold elegance that makes her seem larger than life.
When Tillinghast inches open the door of a black widow's lair for a zoology class demonstration, some students back away, murmuring, "What are you doing?" Others edge closer. (Black widows don't try to escape, he says; they're just hoping you'll go away.) Presented with a live fly, however, the spider suddenly resembles a disembodied black-gloved hand, grabbing and twirling her prey, wrapping it in sticky glue-coated silk that she pulls from her spinnerets with her two hind legs. Tillinghast demonstrates how he collects this silk for his research by touching a glass pipette to the spinnerets at the tip of her abdomen and winding it around and around.
On another occasion, however, a visitor to his lab watches as spider after spider refuses to attack a mealworm or produce the sticky silk. Bemused, Tillinghast looks over the group of black widows he's raised from spiderlings. "Kids," he says. "You can never get them to perform when you want them to."
Contrary to popular belief, the black widow is a rather timid species. Its vicious reputation stems mainly from two things: the female's tendency to devour her mate—which has been somewhat exaggerated, says Tillinghast—and the quality of its venom, which contains a neurotoxin 15 times more potent than that of a rattlesnake. Prompt medical attention is recommended for any black widow bite, but fatalities are extremely rare. For the healthy adult, says Tillinghast, a black widow bite would result in "a bad day."
Very Dangerous Liaisons
It's clear that Tillinghast has developed an affection for the creatures he studies—and especially the garden spider, which he refers to as "she," since he studies the females. (The male is small and inconspicuous, and courts the female by vibrating a strand of her web. He often commits suicide in the act of mating, thus preventing other males from impregnating the same female—unless she manages to toss him aside and make way for other suitors. Or she may simply eat him, providing an extra source of protein for her future offspring, explains Tillinghast.)
Out in a Madbury, N.H., field one summer morning, Tillinghast finds many garden spider webs stretched vertically among the tall grasses. Typically, the large yellow and black spider hangs upside down in the center of the web, with heavy zigzag "writing" above and below. When startled, she clings to the web and vigorously pumps it up and down like a trampoline.
Approaching an empty web, Tillinghast explains that this spider, already spooked, is lying in wait in the grass below, connected to her web by a silk "lifeline." (Although most spiders have eight eyes, their vision is poor, and they rely on vibrations to detect the arrival and whereabouts of their prey.) Suddenly a small grasshopper crashes headlong into the web, and the spider shoots up to the center, flips upside down and darts out to grab her prey. Using her pointy hooked feet, she rapidly spins the grasshopper over and over as silk flows from her spinnerets like jets of spray from a crop-duster airplane. With the grasshopper safely straitjacketed, the spider sinks her fangs into it and then retreats, waiting for it to become paralyzed before returning to inject her saliva, which "predigests" the insect into a meal she can sip at her leisure.
Fearless of a spider's touch, Tillinghast scoops up one with his bare hand and allows it to roam up the front of his T-shirt, onto his bare arm, skirting the open edge of the sleeve, and then around on his back and out of sight. Eventually, he plucks it off and traps it in a translucent cup with a sprig of vetch. Although he is a predator of these predators, he avoids killing spiders if possible and clearly regards them with a sense of wonder. He'll never forget the first time he and Mark Townley '84, '93G, now a UNH instrumentation scientist, stayed up all night to find out when the garden spiders in his lab would start the daily task of eating the old web and spinning a new one. It was 4 a.m. when all the spiders, each in its own Plexiglas home, began to consume their webs in unison. "It was as if the 'Sorcerer's Apprentice' had been struck up," says Tillinghast.
When Tillinghast returns to the lab from his field trip, he scoops a spider out of its capsule and carefully holds it upside down, pinning its legs gently to its sides, except for the front two, which keep reaching out into the air. The disturbed spider emits some of its digestive fluids, as brown as tobacco juice, which Tillinghast catches in a tiny pipette. Then—careful to avoid the reflex tendency to suck in—he blows the contents into a tiny plastic test tube for chemical analysis.
Working with Matthew Foradori '99G, '03G, now a biologist at Edinboro University in Pennsylvania, Tillinghast and Townley have found that spiders have a powerful battery of enzymes in their digestive fluid that can dissolve tissues. There is a chemical in its blood, however, that inhibits those same enzymes from dissolving the spider.
Untangling the Web
Spider silk is five times stronger than steel, weight for weight, and five times more elastic than Kevlar. Unlike manmade synthetics, it is produced at roughly ambient temperature and pressure, and it is also recycled by being consumed by its producers. If humans could find a way to produce a similar material, there could be a slew of applications, including bullet-proof vests, medical sutures, artificial tendons, airplane parts and biodegradable fishing lines. In addition, spider venoms contain whole catalogs of chemicals. Many have yet to be identified, but some are being tested for uses ranging from pain killers to a treatment for erectile dysfunction.
Alas, spiders are not suited to farming. "Put 10,000 of them in a room and a week later you'd have one mean-looking one left," quipped the CEO of a Canadian biotech company that has developed a genetically modifed goat that produces spider-silk protein in its milk. From his own research, Tillinghast notes another problem: It would take 30 garden spiders 10 weeks to make the same amount of silk produced by one silkworm in one day.
To reproduce spider silk, humans must understand not only the material but also the mechanics. Tillinghast, usually in collaboration with Townley and sometimes with UNH plant biologist Christopher Neefus '82G, has made chemical, mechanical and molecular studies of spider silk and its production. "Ed has been one of the most important figures studying the chemistry of silk and particularly in understanding how liquid glues in webs operate," notes Todd Blackledge, a University of Akron researcher. The glue—which is laid down on some of the silk as it is extruded through a spider's spinnerets—is what traps a victim long enough for a spider to wrap it up. This is the part of the web—up to 40-60 percent by weight—that is coated with sugar molecules. It, too, is considered a potential industrial model, for synthetic adhesives. (As to why a spider doesn't get caught in the glue in its own web, Tillinghast says the sticky droplets are spaced out, so that a spider, with its tiny feet, is in effect "never really getting more than a toe stuck. But a flying insect hits the glue in many places. It's like being spot welded to the web." Further, he surmises, "if you took Argiope and threw her into her own web, she'd be stuck, too.")
Tillinghast, Blackledge adds, has also made contributions to the understanding of the mechanics of silk production, studying the different glands that make up a spider's spinnerets, which are capable of producing six different types of silk. "A lot of people take what I call the white-lab-rat approach," says Blackledge. "They study a single species of spider and one kind of silk. But Ed's approach has been to ask broader questions." In addition to Argiope, brown recluses, black widows and barn spiders, Tillinghast has also studied the large golden orb weaver. (He once climbed a tree to rescue one that had escaped). He's studied how spiderlings make a communal hole in the egg sac with their digestive juices when it's time to emerge and how starvation affects the composition of spider webs.
For Tillinghast, there's nothing like scientific discovery and observation. "It's a feeling of joy," he says. "It's our very nature. People want to understand things." So he will continue to pursue his interests in the "damnedest things," using what may seem like improbable methods. Ultimately, some of his results could help lead to new inventions or treatments. Already he has helped increase our understanding of these reviled but abundant creatures—some 40,000 species have been identified so far—with which, for better or worse, we must share the planet.
Tillinghast has no such ambivalence. During a morning spent spider hunting with his wife in the depths of South Carolina's Congaree Swamp some years ago, he had stepped off the boardwalk to search among the clumps of grass when Margaret called out: "Look out, there's a cottonmouth!" Sure enough, one poisonous snake crossed his path and another glided by through the water. Ed and Margaret retreated to the boardwalk, and then they saw it: a spiny orb weaver, resembling a tiny red, white and black crab, at the center of its circular web. The web was flecked with tufts of silk and illuminated by slanting sunlight against a backdrop of ancient trees draped with Spanish moss. "It was a moment of uncommon beauty," he says, "and there I was with the two loves of my life." He only kissed one of them. ~Return to UNH Magazine Features