April 1, 1997 P. Kirk Visscher: A Life Spent Among Bees Deciphering the Swarm By DENISE GRADY CACTUS CITY, Calif. -- Partly shaded by the slender branches of a paloverde tree, his face just inches from a cluster of 5,000 honeybees, Dr. P. Kirk Visscher spoke into a walkie-talkie. "I think these bees are going to take off," he told a colleague stationed 160 yards west, at a wooden nest box that the bees had been scouting in their search for a new home. Indeed, the cluster was becoming jumpier by the minute. Worker bees had begun "buzz running," plowing furiously through the masses of their sisters, as if prodding them to get ready. The buzzing grew louder as the entire cluster pulsated and changed shape. "They're gonna go!" Visscher cried. His partner, Dr. Scott Camazine, came running to watch. By dozens and then hundreds, the bees lifted off into the warm light of a February afternoon in the desert 150 miles east of Los Angeles. Within a minute, all 5,000 were airborne, zooming around in a circular holding pattern 20 or 30 feet in diameter, just barely above the heads of the two entomologists and Richard Vetter, a staff research associate from Visscher's laboratory at the University of California at Riverside. "Streaker" bees that had visited the nest box roared westward across the circle, signaling the others to head that way. A hum filled the dry air. It was like standing in the midst of a tornado of bees. A visitor's first impulse might be to run for dear life or roll up in a ball on the ground, but it would surely give way to wonder at an event that even textbooks and scientific reports cannot resist describing as "spectacular." "Very few people ever see this," Camazine said, smiling. Such behavior, known as swarming, occurs when part of a bee colony leaves the nest to find a new home, and it has been described in detail by various scientists over the years. But important elements remain unexplained, and they are on a seemingly endless list of things that Visscher hopes to learn about bees. An associate professor of entomology at Riverside, Visscher is both a honeybee biologist and a lifelong beekeeper. Of the 20,000 known species of bees, only about six make honey, and one of them, Apis mellifera, the best known and most common, is the focus of much of Visscher's research. He keeps 60 hives -- about three million bees -- on campus. Visscher, 44, a large-framed, graying man more than six feet tall, has the wardrobe of a scientist who spends a lot of time hauling boxes of bees around in the field. His rumpled look and affable manner stand in contrast to his incisiveness on matters of biology. Among his colleagues, Visscher is probably known best for the unusually broad range of his research interests, but that eclectic approach can leave him open to criticism that his efforts are too dispersed. "I do too many things," he said, but it would be hard for him to give up any of his disparate interests. "He's an enormously creative scientist who's done research in a broad range of areas, and many are the critical areas of sociobiology," said Dr. Gene Robinson, who went to graduate school at Cornell with Visscher and is now an associate professor of entomology at the University of Illinois at Urbana-Champaign. "I suppose the flip side of this is that you can't say he's made his mark in this area or that. But his best papers are models of excellence. The experimental design is always crisp." Visscher studies the biology of bees themselves, but they also interest him as social insects with cooperative behaviors shaped by evolution. His scientific publications run from the lofty and theoretical to the unabashedly practical: he has pondered the evolutionary significance of egg laying by worker bees instead of the queen, helped monitor the advance of the notoriously fierce Africanized bees, or so-called killer bees, into California and studied ways to treat diseases in bees as well as the best soap to use to kill unwelcome swarms. He has even designed a "Take-Out Trap," from a Chinese restaurant take-out carton, which is being used by California insect-control agencies to capture Africanized bees. Last year, with Camazine and Vetter, he ventured into the world of medicine, letting himself be stung repeatedly in a study showing that contrary to traditional medical advice, the best thing to do for a bee sting is to yank out the stinger right away. The study may have struck entomologists as a bit whimsical, but it was carefully crafted and accepted by The Lancet, a respected medical journal. It matters to Visscher that the insect he works with is commercially important. Beekeeping, including the sales of honey and bees and the rental of hives to pollinate crops, is a $200 million industry, and pollination by commercial colonies is estimated to add more than $9 billion a year to the value of crops in the United States. Although mite infestations have wiped out wild bee colonies in many parts of the nation, beekeepers have treated their hives successfully with chemicals, including fluvalinate and menthol. The mites may become resistant to the chemicals, however. Bees have been part of Visscher's life for as long as he can remember. Growing up in Montana, where his father practiced medicine and kept bees as a hobby, he was working the hives and harvesting honey before he turned 6. Even so, he did not always intend to become an entomologist. "It feels a little bit accidental," Visscher said. "I did always think I'd get a graduate degree. My father has a medical degree, and both grandfathers had Ph.D.'s. I considered medicine." But when he went to Harvard, he found "a hotbed of social insect work," he said, and "that's when I really discovered entomology." The biology department was infused with excitement by the pioneering work of the sociobiologist Dr. E.O. Wilson on ant societies. It captivated Visscher, and he declared a major in biology. He also kept bees on his back porch in Cambridge. In 1978, when he had to decide on a topic for his senior thesis, bees were a natural. At the suggestion of one of his mentors, Dr. Thomas D. Seeley, he studied the bees that specialize in removing corpses from the nest and showed that they singled out the dead by smell. The work later led to a journal paper in 1983 called "The Honeybee Way of Death," in which Visscher called his subjects "undertaker bees," a designation that has stuck in the scientific literature ever since. That senior thesis caught the eye of Dr. Roger A. Morse, a preeminent bee scientist at Cornell University who invited Visscher there to do graduate work. During his years at Cornell, Visscher began to explore some of the ideas about bee societies that still inform his work today. Among the work he has done that Visscher considers most important and intriguing are studies of what he calls "reproductive conflict." Although it is widely believed, and even stated in textbooks, that worker bees do not lay eggs in colonies with a queen, that is not the case. Some workers do; they lay unfertilized eggs that can develop into males, known as drones. In studies published in 1989, Visscher showed that workers laid far more eggs than researchers had previously thought. But hardly any of those eggs survive because other workers sniff them out and devour them. The phenomenon raises evolutionary questions that he continues to study. If one accepts the idea that individual organisms evolve behaviors designed to pass along their genes, then it makes sense that the workers should try to reproduce. Their own offspring will, after all, carry more of their genes than the queen's offspring. Then again, if one worker can reproduce, so can her nestmates, most of whom are half-sisters -- but their offspring carry even fewer of her genes than the queen's. So it makes sense for the workers to behave as they do, destroying each other's eggs and attacking other workers whose ovaries begin to develop. But why, then, do they lay eggs in the first place? "It remains unresolved," Visscher said. The project that he and Camazine are pursuing now concerns swarming. Bees generally swarm in spring, when the hive becomes too crowded. Workers begin rearing a new queen, and the old queen, often against her will, is swept out of the hive by a swarm that may contain 10,000 to 20,000 bees, between 30 percent and 70 percent of the original colony. The swarm, clustered around the old queen, settles for a few days in an interim spot, often a tree branch, while scouts, arising from the ranks of worker bees, fly off to find a new site for a hive. When they return, the scouts do a dance for their nestmates that is similar to the one forager bees perform to direct others to food. Scouts make up perhaps 5 percent of the swarm. Some visit more than one site, and different scouts dance for different sites. Nonetheless, the moment arrives when the entire swarm takes to the air, and, somehow, all the bees go in the right direction to the new site. "How do the bees achieve a unanimous decision?" Visscher asked. Camazine said, "It's one of the last remaining great questions about honeybees, and Kirk is the ideal person to collaborate with." Camazine, an emergency room doctor, has put medicine aside to become an assistant professor of entomology at Pennsylvania State University. Most researchers think that the scouts visit various sites, compare them somehow in whatever is the bee equivalent of a mind, pick the best one and then dance for it, so that much of the dancing eventually represents one site, which the swarm then occupies. Visscher and Camazine are not so sure that bees make comparisons, and the experiments they have been conducting in Cactus City have been designed to test the idea. They take a small swarm from one of Visscher's hives and set it on a plywood stand in a stretch of desert that has virtually no sites, such as hollow trees or caves, that would attract bees looking for a home. That way, the swarm will go to nest boxes set up by the researchers, who post themselves at the boxes and mark scouts with a shade of paint that will reveal which box they visited. Any bee that shows up at one box after visiting another -- as shown by the paint marking -- is destroyed. That eliminates the possibility of comparison by a single scout. If that kind of comparison is important, the scientists reason, then the swarm should be unable to decide where to go without it, or, at the very least, should take significantly longer to decide. Although the experiments are still under way, Visscher said, there are hints that the findings will challenge existing notions about how swarms go about finding a new home. Visscher expects the project to take several years and to open other avenues of inquiry. The idea that some scouts may dance for one site, visit another and then change their dance to favor the second site -- something that in Visscher's earlier studies has been vanishingly rare -- has inspired some researchers to suggest that bees might be capable of forming a mental construct based on what they have seen. At this point, Visscher is not sure that is possible. "Sometimes it seems as if bees can do anything," he said. "Do they really act as an automaton? Or is there some degree of awareness? It's difficult to think of an experiment to tell which an animal is doing. I wonder what it is to be a bee." Copyright 1997 The New York Times Company