By SETH BORENSTEIN, AP Science WriterWed May 2, 6:40 PM ET
Unless someone or something stops it soon, the mysterious killer that is wiping out many of the nation's honeybees could have a devastating effect on America's dinner plate, perhaps even reducing us to a glorified bread-and-water diet.

Honeybees don't just make honey; they pollinate more than 90 of the tastiest flowering crops we have. Among them: apples, nuts, avocados, soybeans, asparagus, broccoli, celery, squash and cucumbers. And lots of the really sweet and tart stuff, too, including citrus fruit, peaches, kiwi, cherries, blueberries, cranberries, strawberries, cantaloupe and other melons.

In fact, about one-third of the human diet comes from insect-pollinated plants, and the honeybee is responsible for 80 percent of that pollination, according to the U.S. Department of Agriculture.

Even cattle, which feed on alfalfa, depend on bees. So if the collapse worsens, we could end up being "stuck with grains and water," said Kevin Hackett, the national program leader for USDA's bee and pollination program.

"This is the biggest general threat to our food supply," Hackett said.

While not all scientists foresee a food crisis, noting that large-scale bee die-offs have happened before, this one seems particularly baffling and alarming.

U.S. beekeepers in the past few months have lost one-quarter of their colonies — or about five times the normal winter losses — because of what scientists have dubbed Colony Collapse Disorder. The problem started in November and seems to have spread to 27 states, with similar collapses reported in Brazil, Canada and parts of Europe.

Scientists are struggling to figure out what is killing the honeybees, and early results of a key study this week point to some kind of disease or parasite.

Even before this disorder struck, America's honeybees were in trouble. Their numbers were steadily shrinking, because their genes do not equip them to fight poisons and disease very well, and because their gregarious nature exposes them to ailments that afflict thousands of their close cousins.

"Quite frankly, the question is whether the bees can weather this perfect storm," Hackett said. "Do they have the resilience to bounce back? We'll know probably by the end of the summer."

Experts from Brazil and Europe have joined in the detective work at USDA's bee lab in suburban Washington. In recent weeks, Hackett briefed Vice President Cheney's office on the problem. Congress has held hearings on the matter.

"This crisis threatens to wipe out production of crops dependent on bees for pollination," Agriculture Secretary Mike Johanns said in a statement.

A congressional study said honeybees add about $15 billion a year in value to our food supply.

Of the 17,000 species of bees that scientists know about, "honeybees are, for many reasons, the pollinator of choice for most North American crops," a National Academy of Sciences study said last year. They pollinate many types of plants, repeatedly visit the same plant, and recruit other honeybees to visit, too.

Pulitzer Prize-winning insect biologist E.O. Wilson of Harvard said the honeybee is nature's "workhorse — and we took it for granted."

"We've hung our own future on a thread," Wilson, author of the book "The Creation: An Appeal to Save Life on Earth," told The Associated Press on Monday.

Beginning this past fall, beekeepers would open up their hives and find no workers, just newborn bees and the queen. Unlike past bee die-offs, where dead bees would be found near the hive, this time they just disappeared. The die-off takes just one to three weeks.

USDA's top bee scientist, Jeff Pettis, who is coordinating the detective work on this die-off, has more suspected causes than time, people and money to look into them.

The top suspects are a parasite, an unknown virus, some kind of bacteria, pesticides, or a one-two combination of the top four, with one weakening the honeybee and the second killing it.

A quick experiment with some of the devastated hives makes pesticides seem less likely. In the recent experiment, Pettis and colleagues irradiated some hard-hit hives and reintroduced new bee colonies. More bees thrived in the irradiated hives than in the non-irradiated ones, pointing toward some kind of disease or parasite that was killed by radiation.

The parasite hypothesis has history and some new findings to give it a boost: A mite practically wiped out the wild honeybee in the U.S. in the 1990s. And another new one-celled parasitic fungus was found last week in a tiny sample of dead bees by University of California San Francisco molecular biologist Joe DeRisi, who isolated the human SARS virus.

However, Pettis and others said while the parasite nosema ceranae may be a factor, it cannot be the sole cause. The fungus has been seen before, sometimes in colonies that were healthy.

Recently, scientists have begun to wonder if mankind is too dependent on honeybees. The scientific warning signs came in two reports last October.

First, the National Academy of Sciences said pollinators, especially America's honeybee, were under threat of collapse because of a variety of factors. Captive colonies in the United States shrank from 5.9 million in 1947 to 2.4 million in 2005.

Then, scientists finished mapping the honeybee genome and found that the insect did not have the normal complement of genes that take poisons out of their systems or many immune-disease-fighting genes. A fruitfly or a mosquito has twice the number of genes to fight toxins, University of Illinois entomologist May Berenbaum.

What the genome mapping revealed was "that honeybees may be peculiarly vulnerable to disease and toxins," Berenbaum said.

University of Montana bee expert Jerry Bromenshenk has surveyed more than 500 beekeepers and found that 38 percent of them had losses of 75 percent or more. A few weeks back, Bromenshenk was visiting California beekeepers and saw a hive that was thriving. Two days later, it had completely collapsed.

Yet Bromenshenk said, "I'm not ready to panic yet." He said he doesn't think a food crisis is looming.

Even though experts this year gave what's happening a new name and think this is a new type of die-off, it may have happened before.

Bromenshenk said cited die-offs in the 1960s and 1970s that sound somewhat the same. There were reports of something like this in the United States in spots in 2004, Pettis said. And Germany had something similar in 2004, said Peter Neumann, co-chairman of a 17-country European research group studying the problem.

"The problem is that everyone wants a simple answer," Pettis said. "And it may not be a simple answer."

Could Genetically Modified Crops Be Killing Bees?

By John McDonald, Special to The Chronicle
San Francisco Chronicle
March 10, 2007

With reports coming in about a scourge affecting honeybees, researchers are launching a drive to find the cause of the destruction. The reasons for rapid colony collapse are not clear. Old diseases, parasites and new diseases are being looked at.

Over the past 100 or so years, beekeepers have experienced colony losses from bacterial agents (foulbrood), mites (varroa and tracheal) and other parasites and pathogens. Beekeepers have dealt with these problems by using antibiotics, miticides or integrated pest management.

While losses, particularly in overwintering, are a chronic condition, most beekeepers have learned to limit their losses by staying on top of new advice from entomologists. Unlike the more common problems, this new die-off has been virtually instantaneous throughout the country, not spreading at the slower pace of conventional classical disease.

As an interested beekeeper with some background in biology, I think it might be fruitful to investigate the role of genetically modified or transgenic farm crops. Although we are assured by nearly every bit of research that these manipulations of the crop genome are safe for both human consumption and the environment, looking more closely at what is involved here might raise questions about those assumptions.

The most commonly transplanted segment of transgenic DNA involves genes from a well-known bacterium, bacillus thuringiensis (Bt), which has been used for decades by farmers and gardeners to control butterflies that damage cole crops such as cabbage and broccoli. Instead of the bacterial solution being sprayed on the plant, where it is eaten by the target insect, the genes that contain the insecticidal traits are incorporated into the genome of the farm crop. As the transformed plant grows, these Bt genes are replicated along with the plant genes so that each cell contains its own poison pill that kills the target insect.

In the case of field corn, these insects are stem- and root-borers, lepidopterans (butterflies) that, in their larval stage, dine on some region of the corn plant, ingesting the bacterial gene, which eventually causes a crystallization effect in the guts of the borer larvae, thus killing them.

What is not generally known to the public is that Bt variants are available that also target coleopterans (beetles) and dipterids (flies and mosquitoes). We are assured that the bee family, hymenopterans, is not affected.

That there is Bt in beehives is not a question. Beekeepers spray Bt under hive lids sometimes to control the wax moth, an insect whose larval forms produce messy webs on honey. Canadian beekeepers have detected the disappearance of the wax moth in untreated hives, apparently a result of worker bees foraging in fields of transgenic canola plants.

Bees forage heavily on corn flowers to obtain pollen for the rearing of young broods, and these pollen grains also contain the Bt gene of the parent plant, because they are present in the cells from which pollen forms.

Is it not possible that while there is no lethal effect directly to the new bees, there might be some sublethal effect, such as immune suppression, acting as a slow killer?

The planting of transgenic corn and soybean has increased exponentially, according to statistics from farm states. Tens of millions of acres of transgenic crops are allowing Bt genes to move off crop fields.

A quick and easy way to get an approximate answer would be to make a comparison of colony losses of bees from regions where no genetically modified crops are grown, and to put test hives in areas where modern farming practices are so distant from the hives that the foraging worker bees would have no exposure to them.

Given that nearly every bite of food that we eat has a pollinator, the seriousness of this emerging problem could dwarf all previous food disruptions.

I hadn't really noticed a lack of bees but now that you mention it I've only seen a few this year. It's still rather cold so I'm thinking they're just not out yet. There is a lot of agriculture, especially cattle in this area. I hope they'll be alright.
I sure don't have a shortage of birds. They clean out my feeders in a few hours of a gallon of seeds. Do you suppose this is why? There isn't any seeds for them to eat? They practically attack me when I fill the feeders.