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Honeybee Disappearance Puzzles Scientists

April 3, 2007 at 3:40 PM EST
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SPENCER MICHELS, NewsHour Correspondent: In California’s lush Central Valley, the fruit and nut trees are in bloom, but the honeybees that pollinate those trees so they will bear fruit are in short supply.

One of California’s top crops, almonds, is completely dependent on bees for pollination. There aren’t nearly enough wild or native bees to do the job, and California commercial beekeepers can supply only half of the hives needed.

So bees raised by migratory beekeepers from around the country are trucked in, but this year there’s a big problem.

So this is what, is it like a cemetery for beehives?

LANCE SUNDBERG, Beekeeper: Yes, in a way, it is.

SPENCER MICHELS: Late last year, beekeeper Lance Sundberg brought 2,100 colonies of bees to California from Montana and other states. A month later, he discovered that two-thirds of the bees had disappeared.

LANCE SUNDBERG: It was like as if they took off and went to work, and they just failed to come back. And no sign of dead bees, and that’s the unusual phenomenon.

SPENCER MICHELS: Many of the bees died or vanished before he could rent them out to growers, apparently victims of a nationwide problem now being called colony collapse disorder.

He stacked completely dead hives under tarps. Here, so-called robber bees are stealing abandoned honey, and he’s put ailing hives beside a lake hoping they might recover.

LANCE SUNDBERG: So a normal colony at this time would have bees wall-to-wall.

SPENCER MICHELS: That would be 30,000 bees probably.

LANCE SUNDBERG: Thirty thousand to sixty thousand bees. And right now, this one’s down to probably 3,500 bees or less.

Colony collapse disorder

Charleen Carroll
Bee Broker
It's something that we've seen for probably 15 years at least, and it depends on the beekeeper.

SPENCER MICHELS: Colony collapse disorder, a malady of unknown origin, has shown up in 24 states over the last year and could, if not stopped, jeopardize up to $18 billion in crops that bees pollinate.

The motels around Oakdale, 90 miles east of San Francisco, are full this time of year with worried beekeepers from around the country. At Cathy and Carol's Coffee Shop, a beekeepers' hangout in the tiny town of Waterford, we sat down with a bee broker, two beekeepers, and a scientist.

Like many people in the industry, bee broker Charleen Carroll says die-offs have been happening frequently in recent years.

CHARLEEN CARROLL, Bee Broker: It's something that we've seen for probably 15 years at least, and it depends on the beekeeper.

SPENCER MICHELS: But beekeepers Louise Rossberg and Bob Olmo think there is something different going on this year.

LOUISE ROSSBERG, Beekeeper: Every lid we pop open, there's no bees in the box. We lost about 90 percent of our business.

BOB OLMO, Beekeeper: I lost 50 percent of my operation. There's no bees in the box.

SPENCER MICHELS: Do you have any clue as to what's going on?

BOB OLMO: No, I don't. I've never seen it before. And it's pretty hard to lose 50 percent or 60 percent of your business and stay in business.

JERRY BROMENSHENK, University of Montana: There's a whole variety of folks looking at whether it's something new or something cyclic that we've seen before and it's just particularly widespread this time around and unusually severe.

SPENCER MICHELS: Jerry Bromenshenk, an entomologist at the University of Montana and a private consultant to the bee industry, has visited sites of bee die-off around the country.

JERRY BROMENSHENK: It could be some type of disease pathogen, an unknown virus, for example, but there doesn't seem to be anyway to slow it down, stop it once it starts.

Honeybee organization

Laurie Adams
North American Pollinator Protection
The result is the complete fertilization within the plant, so the plant is able to set seeds and set fruit, which it normally might not be able to do without that.

TEACHER: Would you like to go inside to take a look?

SPENCER MICHELS: As children learn early in places like San Francisco's Randall Museum, European honeybees imported to America by early colonists are complex creatures with a highly developed social structure.

NANCY ELLIS, Randall Museum: The society of the honeybee is made up of one queen, several thousand workers, which are all female bees, and then several hundred that are males, called drones.

SPENCER MICHELS: But for all their organizations, says the museum's Nancy Ellis, bees -- even those in this carefully controlled display -- seem defenseless against the current die-off.

NANCY ELLIS: About three or four weeks ago, this was jammed with bees. And right now, you can only see just a few stragglers still inside. I don't really know what caused this hive to go.

SPENCER MICHELS: Solving that mystery and the larger one are important, because bees and other pollinators like hummingbirds perform a crucial function in agriculture. Various attempts to spread pollen without them have never worked well.

As bees gather nectar and pollen, they flit between blossoms, doing what the birds and the bees do. Laurie Adams heads the North American Pollinator Protection Campaign.

LAURIE ADAMS, North American Pollinator Protection Campaign: The male part of the plant is moved toward the female part of the plant or toward the female part of another plant.

SPENCER MICHELS: And a bee or another pollinator does this?

LAURIE ADAMS: Absolutely. The result is the complete fertilization within the plant, so the plant is able to set seeds and set fruit, which it normally might not be able to do without that.

Bee stressors

Eric Mussen
University of California, Davis
I think that one of the biggest stresses was the fact that the United States has been in a drought in many places, and the plants are just not providing the food that the bees need to be really successful.

SPENCER MICHELS: Because pollinators are essential in growing up to one-third of the typical American's diet, she contends the food supply is threatened. The problem for many pollinators, she says, is the loss of habitat where homes are replacing fields.

But scientists searching for the cause of colony collapse disorder are focusing on a long list of other suspects.

ERIC MUSSEN, University of California, Davis: What they live in is a hive, whether it's a box that we made or whether it's a hollowed-out tree.

SPENCER MICHELS: At the University of California at Davis, Eric Mussen gives advice to beekeepers, and they've been calling non-stop. He suspects the bee die-off may be related to the weather, which stresses the bees.

ERIC MUSSEN: I think that one of the biggest stresses was the fact that the United States has been in a drought in many places, and the plants are just not providing the food that the bees need to be really successful.

SPENCER MICHELS: Bees can also be stressed by traveling long distances to get to orchards that need them. And scientists are looking at pesticides that might kill bees by contaminating the nectar and the pollen they gather.

Another suspected culprit is mites that suck the blood from both adult and unborn bees and can transmit viruses into the colony. That's what Orin Johnson suspects. Johnson is president of the California Beekeepers Association and a second-generation beekeeper.

ORIN JOHNSON, California State Beekeepers Association: The Varroa mite is the worst malady we have. It spins off viruses; it weakens the colony; it makes it susceptible for a lot of other maladies. If you don't keep the mites under control, you're going to lose a lot of colonies for sure.

SPENCER MICHELS: Johnson uses medicines to control the mites, and he's not lost very many bees this year, though he has lost some.

ORIN JOHNSON: This is a classic symptom of the colony collapse or disappearing bee. Your hive, your box, or your combs will have plenty of honey. The hive has plenty of food. They're not dying from starving; they have everything they need. So why are they disappearing or dying?

SPENCER MICHELS: Other hives are in great shape, and he can't explain why.

ORIN JOHNSON: If every hive looked like this, I'd just be ecstatic. But even now, after the build-up in the almonds, I'll still have a certain percentage that just don't get healthier. They get worse. And that's some of the dilemma.

Solving the disappearances

Jim Jasper
Almond Grower
Four or five years ago, we were paying maybe $40, $50 a hive. And now hives are up to $150 a hive. Without bees, we would really be lost, as far as producing almonds here in California.

SPENCER MICHELS: While the beekeeping community complains that there isn't enough research going on into what is causing colony collapse disorder, there is some, and the aim of much of it is to find out what goes on in the hive when the beekeeper isn't there.

Jerry Bromenshenk is working on a listening device whose signals can be sent via satellite to a beekeeper miles away.

JERRY BROMENSHENK: We found that sound can be used as a diagnostic that tells whether a colony is having any health problems.

SPENCER MICHELS: But only a few institutions are doing intense scientific work on colony collapse disorder. The U.S. Department of Agriculture Bee Research Lab in Maryland has collected bee samples from around the country. Jeff Pettis is research leader.

JEFF PETTIS, USDA Bee Research Lab: At this point, we've ruled very little out. In the lab, we're looking at those for tracheal mites, Varroa mites.

SPENCER MICHELS: Pettis acknowledges the investigation is at an early stage.

JEFF PETTIS: I still wouldn't rule out unknown pathogen, because the symptoms that we're seeing don't match up with the things that we know, that we currently know.

SPENCER MICHELS: Jim Jasper would like some answers. He heads one of the biggest almond-growing and processing firms in California, a state that produces 80 percent of the world's almonds, about a billion pounds a year.

Business has been booming of late, as worldwide demand has expanded. More trees have been planted, and that has upped the demand for bees and the price Jasper has to pay to rent them for about a month.

JIM JASPER, Stewart and Jasper Orchards: Four or five years ago, we were paying maybe $40, $50 a hive. And now hives are up to $150 a hive. Without bees, we would really be lost, as far as producing almonds here in California.

SPENCER MICHELS: Meanwhile, as the almond blossoms fade, beekeepers like Tom Hamilton of Idaho are pulling their bees out of these orchards at night when the bees are calm and preparing to move onto the next crop, cherries in California or apples in Washington State.

The crisis hasn't hit Hamilton's bees, nor has it crippled the almond industry, at least not yet.

TOM HAMILTON, Beekeeper: I think we're going to be able to solve this problem, but right now it's a little stressful.

SPENCER MICHELS: Growers and beekeepers alike fear that, without more academic and government research, the bee die-off will turn into a very costly, unsolved mystery.