A Little Critter in Big Trouble

A Little Critter in Big Trouble header image
No one seems to notice, but mites are killing most of our wild honey bees.

Think back, for a moment, to your childhood. To a warm spring day. A nice day, of course. Not the time you got in trouble and lost your allowance. Forget about that.

Think about the smell of fresh-cut grass, hamburgers grilling on the barbecue. Butterflies wafting in the breeze. Playing catch with your dad or hopscotch on the front sidewalk. Honey bees bouncing from flower to flower.

Those were the golden days. The sun was still up past bedtime. Pleasures were simple. The ice cream was so cold it hurt the roof of your mouth, and memories were forged to give your life a foundation.

Now adjust the image to the present.

You can still grill a hamburger. You can still play catch or hopscotch, and if you plant the right flowers a few butterflies might even come.

But the honey bees? Forget about it.

Maybe it doesn't seem like a big deal. But a little piece of our world has rapidly disappeared almost without notice.

The spotted owls are called the endangered species. AIDS, crime and budget battles fill the headlines. And hardly anyone notices that the wild honey bee, that simple little fixture of our spring and summer days, has quietly gone away. And it may be a long, long time before it comes back.

Dozens of bees in a hive.

Photo: Lynn Ketchum

This isn't a story about losing a species. Honey bees are not extinct. And it isn't even a story about huge economic losses or disrupted agricultural systems. You can still find honey bee colonies in commercial orchards, managed by expert apiculturists. And some other ratty little bee that lives in the dirt will probably pollinate your cherry tree or vegetable garden. In fact, if you don't want to you don't have to notice that almost all the wild honey bees are gone.

But they are, and some people don't like it.

"I know of a man who wanted to rent a commercial beehive so he could have the sight and sound of honey bees back in his garden," said Michael Burgett, a professor of entomology at Oregon State University. "Hardly a week goes by that someone doesn't ask me what happened to the honey bees."

Burgett, internationally recognized as an expert on honey bees, saw it all coming, about as early as anyone in the world. The demise of our wild honey bees may be a surprise to most of us, but he's been warning about the looming crisis for almost a quarter of a century.

A lone bee flying to a hive.

Photo: Lynn Ketchum

To Burgett, it was an expected but unwelcomed event when he got a call late one night in 1984 from a colleague, an apiculturist at the University of California. The call was part of an early system entomologists had set up to spread the word quickly in the event of a disaster. It was the only time Burgett can recall the warning system being used.

"Mike, they've found tracheal mites in Louisiana," said the voice on the other end of the phone.

Most people would have no idea what that meant. Burgett did, and it made him a little numb. An integral part of America's heritage was on the way out, even if it would take another decade for the rest of the nation to realize it.

"Wow," Burgett thought at the time. "Here we go."

The caller was talking about parasitic tracheal mites, which entomologists know to be a deadly parasite of the European honey bee, Apis mellifera. It wasn't news that they could be devastating to this species of honey bee, because the first big losses had happened on the Isle of Wight in the English Channel around 1920.

"We knew all about this parasite," Burgett said, "and had for some time. In fact, a law was passed in 1922 in the United States banning all honey bee imports, specifically to exclude the tracheal mite. Even back then we knew it would be a disaster."

Bearded man looking at a hive filled with bees.

OSU entomologist Mike Burgett with a swarm of wild honey bees in a Willamette Valley peach orchard. Eventuyally parasitic mites may kill up to 99 percent of the state's wild honey bees, Burgett fears. Photo: Lynn Ketchum

That law, Burgett said, actually did its job pretty well for more than half a century. But then tracheal mites started showing up in Mexico and, finally, in the United States in 1984. Then, with shocking speed, the highly mobile commercial honey bee industry spread them all over the nation-within two years.

The worst was still to come.

In 1975, on a trip to Thailand-one of many he's made to various parts of the world studying bees-Burgett wrote one of the first professional descriptions of Varroa jacobsoni, more commonly known as the varroa mite. The article, titled "A Prospective Pest of Honey Bees in Many Parts of the World," was about one and a half pages long and was published in the journal Bee World.

Looking back, the article was a classic understatement.

"Professional people saw the paper, they read it, they said, 'gee, how interesting,' and then they forgot about it," Burgett said. "But I knew 20 years ago that the damage from varroa mites could make tracheal mites look like a Sunday ice cream party."

Microscopic view of a mite.

Deadly honey bee enemy: Photo, taken with an electron microscope, of the trachael mite.

Tracheal mites can infect honey bees, but at least they're a native parasite for European honey bees and don't always kill a bee colony. Varroa mites are native to Asian honey bees, which have some different types of defense mechanisms. Our honey bee species does not, and a colony infected with varroa mites inevitably will die within a year or two.

In 1987, the news came in. Varroa mites had been found in Wisconsin.

Microscopic view of a mite.

Deadly honey bee enemy: Photo, taken with an electron microscope, of the varroa mite.

"People, including me, were shocked how fast the tracheal and varroa mites spread," Burgett said. "I don't know why we should have been. The United States beekeeping industry is one of the most mobile, fluid industries in the world. Beekeepers often congregate in the South during the winter, in the Dakotas during the summer, and in between they go all over the country."

At first, under the naive assumption it could still do something, the U.S. Department of Agriculture's Animal and Plant Health Inspection Service fought back. It tried to identify infected bee colonies and destroy them. Organizations such as the Oregon Department of Agriculture joined in, killing 1,500 honey bee colonies in southern Oregon in 1986.

Such efforts accomplished nothing other than to infuriate and impoverish a number of commercial beekeepers. By the late 1980s the genie was very much out of the bottle, and the futile hive eradication programs soon ended.

"It took us a little while to realize the obvious," Burgett said. "The parasitic mites were everywhere."

Commercial beekeepers, and to a far lesser extent "hobbyist" beekeepers, were soon anxiously seeking help against the mites. In 1986 Burgett faced an overflow crowd at one meeting in southern Oregon's Jackson County. Its participants urged the university to begin research programs that would develop effective mite controls.

OSU's research program, and others like it, soon succeeded in developing chemicals and control regimens that commercial beekeepers could use to protect their colonies. These miticides are reasonably effective if conscientiously applied.

But this is easier said than done. "Even with the best commercial beekeepers, who really know what they're doing, the mites have doubled the usual amount of dead colonies during the winter," Burgett said. "And hobbyist beekeepers without the knowledge or patience to use these chemicals have been leaving the field in droves."

Beekeeper looking at a beehive.

Wild honey bees in Malaysia. In his research overseas, OSU's Burgett often comes home with information about potential threats to Oregon. The varroa mites threatening Oregon honey bees came from Asia.

The commercial impact of these parasitic mites, Burgett said, has not been trivial. Pollination fees have doubled in the past 10 years, and wholesale honey prices are up 90 percent in the past two years. If there is a silver lining to any of this, it's that the commercial beekeepers who are really at the top of their game are having banner years-honey is bringing top dollar, and for pollination that depends on honey bees, commercial beekeepers are now the only game in town.

"It's not easy," Burgett said. "I know one beekeeper near Molalla who really knows his business and runs about 1,000 hives. He didn't think he had any mite infestation yet. But he saw a few crawling around, did a sampling of 100 hives and found mite infestation in 95 of them."

There's still a real concern, Burgett said, about the mites developing resistance to the chemicals available to control them. And honey bees are not a big-ticket item like corn, wheat or cattle-for the giant agro-chemical companies, so there's not a lot of money to be made in parasitic mite research and developing new chemical controls. But all things considered, the commercial beekeepers and their bees will survive.

The wild hives are not so lucky.

"We'd like to be able to offer more hope," Burgett said, "but the reality is that in the United States today, most honey bee colonies without chemical treatments will soon become infected with parasitic mites and soon after that they will die."

Will every last one of the wild colonies die? Probably not, but the limited research done so far indicates that at least 80 to 90 percent will, and the numbers may soon approach 95 to 99 percent.

Will natural resistance develop? Yes, it might, Burgett said. But because there's a constant intermingling of wild bees and commercially kept bees, any resistance that does develop will automatically get watered down, in a genetic sense, by the infected commercial hives.

"In theory, we might identify bees with mite resistance more quickly if we allowed almost all the honey bee colonies to die," Burgett said. "What we're doing now is literally encouraging survival of the weakest, and that's not great. But the alternative is just too Draconian."

For the wild bees it's almost over. In the past, a healthy natural colony might have persisted for up to 50 years. Today, because it will be infected with parasitic mites, it will be lucky to reach age two.

Beekeeper with a tray of bees.

Miticides are helping commercial beekeepers control deadly trachael and varroa mites. But who looks out for wild honey bees? Photo: Lynn Ketchum

"Probably 90 percent or more of the nation's wild honey bees are already dead," Burgett said. "The harsh winter of 1995­96 helped finish them off. Pretty soon the only wild hives left will be colonies that have swarmed and escaped from human-kept hives."

Just how many wild bees have died? Frankly, nobody knows. Honey bees were brought to America from Europe in the 1620s, and the North American climate was honey bee heaven for them. They thrived.

"We still don't have a good database on wild honey bees because it just never seemed an important thing to study," Burgett said. "Common sense told you there were a lot of hives, but exactly how many? No one seemed to know or care."

A survey once done in New York indicated, for that ecosystem, that there were about 10 wild honey bee colonies per square mile. A study done in the Sonoran Desert of the American Southwest, which doesn't exactly sound like prime bee country, found as many as 20 colonies per square mile. Suffice it to say there used to be several million wild honey bee colonies, and probably a lot more than that.

Early settlers prized honey bees for their honey (used as a natural sweetener), for their honeycombs (for their wax) and for their role in pollination of crops. As the nation grew, settlers in covered wagons literally carried the bees across the prairies. In the America of the mid-1800s, a nation of small farms, practically every farm kept a hive or two for personal uses.

"Honey bees are part of our heritage," Burgett said. "When most people think of a bee, they think of a honey bee."

You see them in advertising, in your garden, on your trees, in children's storybooks, and in movies. Remember the "bee tree" scene in the movie "Fried Green Tomatoes?" And to help explain the wonders of the insect world, honey bees are the bug of choice. Almost every young student learns about queen bees, drones, the intricacies of bee communication, the essential role each bee plays in supporting survival of the colony. Life lessons intermingle with entomology.

"I've never seen a child yet who wasn't fascinated by a honey bee colony," Burgett said. "More than 20 years ago I started a college course that was focused on honey bee biology, and a prime motivation for that course was the demand by K­12 teachers."

Pear trees filled with white blossoms.

Honey bees managed by humans pollinate hundreds of millions of dollars worth of Oregon crops each year, like these pear trees.

And the honey bee-human connection goes back a lot further than the European settlement of America.

"The most credible studies suggest that Apis mellifera, our European honey bee, actually evolved in Africa about 2.5 million years ago," Burgett said. "That parallels the age of the genus Homo, which of course later came to include Homo sapiens. Apis mellifera eventually became most dominant in Europe, became our modern honey bee and evolved along with humans themselves and the human use of agriculture."

Honey bees were considered sacred in pre-Christian and Egyptian societies. The Bible suggests Jesus Christ was weaned on butter and honey and was offered a piece of honeycomb to eat just before his ascent to heaven. Islamic prophet Mohammed cited honey as a remedy for every illness of the body, and the Koran cites it as a remedy for mental illnesses.

Burgett succumbed later in life to fascination with the honey bee.

"I've always loved biology and entomology, but I just kind of happened into a career studying honey bees," he said. "A research assistant job was open in that area when I began graduate school. So you could say my love affair with honey bees was sort of an arranged marriage. It took me about a year to realize this was the most marvelous creature on the face of the Earth."

Burgett said he hopes the demise of the wild honey bee is a temporary phenomenon. Mite-tolerant bees may develop, he said. Maybe. Someday.

"Mite tolerance could develop through genetic diversity," he said, "but right now the only restocking of wild bees is being done by swarms escaping from our commercial beekeepers. And in that commercial industry, literally thousands of genetically similar queens are being produced by just a few queens. That won't yield much diversity."

Burgett's efforts will continue. On various research projects he's already been to Thailand (17 times), China, Indonesia, Australia, Belize, Uruguay, Argentina, Russia, Egypt and Turkey. Other problems continue to occupy his attention too, not the least of which is the continued spread of Africanized bees in the American South and Southwest.

Bearded man placing a strip on a mossy tree.

Burgett puts a chemical strip in a bee tree. When wild honey bees return to the tree they'll walk on the sticky chemical, which controls parasitic mites that could kill them. Photo: Lynn Ketchum

Lest home gardeners panic about the demise of wild honey bees, he notes that other bees will pick up the pollination slack.

There are 3,500 species of bees in the United States, many of which will pollinate one or many plant species. Soon your cherries, apple trees, flowers and fruit gardens may owe their pollination to bumblebees, mason bees, sweat bees or even the "mining mud bee." These insects are often tiny, live in holes in the ground or elsewhere, and go about their work sight unseen. People can and will learn to live without the honey bee.

It's been sad but interesting, Burgett said, to see how this mite epidemic evolved. He used to get several dozen calls a year from Corvallis-area residents who wanted him to come pick up wild honey bees swarming near their homes.

"I was able to track the intensity of the mite epidemic simply as the phone stopped ringing in the mid 1990s," he said.

Right now, Burgett said, there's some refill of wild colonies by commercial swarms. For climatic reasons, 1997 in Oregon seems to be an unusually good year for bees to swarm (take off from their human keepers and form new colonies). What those bees don't know is that without the supportive chemicals provided by beekeepers, they're doomed. It's a tough time for an insect that has been so naturally successful, and revered, through thousands of years.

The wild honey bee is nothing more, or less, than an insect that's been with human beings since we left the Neanderthals behind and tried to start farms, get our crops pollinated, produce wax candles and enjoy foods that tasted a little sweeter.

Through countless generations they've been around, along with flowers, butterflies and cool winds, as we enjoyed warm spring days. But many of us took them for granted. We still have most of it. But not all, and the spring is a little more silent for the loss.

Published in: Food Systems, Ecosystems