What’s Killing Our Bees?

UT researchers race to understand colony collapse before worldwide food sources are compromised—and before it explodes in East Tennessee

The queen bee, noted by a blue dot, surrounded by her sterile female worker bees. In Colony Collapse Disorder, no adult bees are left in the hive, only “brood” and food stores.

photo by David Luttrell

The queen bee, noted by a blue dot, surrounded by her sterile female worker bees. In Colony Collapse Disorder, no adult bees are left in the hive, only “brood” and food stores.

U.S. honeybee numbers had been declining for about 60 years, but in 2007 it got eerie. Beekeepers were finding failed hives without a single adult bee, only immature bees “capped” in the comb, and food stores still in place, both honey and bee bread. Not just a few: close to 30 percent of the nation’s 2 million-plus managed honeybee colonies were failing, almost three times as many as usual, and a third of those were collapsing in mysterious circumstances. The phenomenon, known as Colony Collapse Disorder, was global, with countries from China to Spain experiencing similar deaths.

The USDA rushed to form a task force, but the next year was the same sci-fi scenario—only with even more colonies collapsing, 35 percent of them failing in suspicious conditions.

Here in Tennessee those same years, the deaths weren’t as mysterious—there were adults still present in the failed hives, for example—but the loss rates were about the same, and completely unacceptable, says Michael Wilson, an entomology grad student at the University of Tennessee who has apiaries in Clinton, Morgantown, and South Knoxville, five in all.

“Some beekeepers are philosophical about heavy losses, I’m not,” he says. “I don’t like it at all. Part of agriculture is trying to keep things alive, and these losses are a real problem.”

In the past year, he lost 12 of his 40 managed bee colonies, and his 30 percent loss jibes with the overall rate in Tennessee, which has climbed from a norm of 10 percent in 2005 to closer to 29 percent of residential colonies lost each year since 2006.

Our state’s colony failures have all been traced back to known causes, such as mites, nosema fungus, starvation, pesticide poisoning, and foulbrood. Although upsetting to the state economy and individual keepers, there are at least proven tools to deal with these maladies. In contrast, CCD-ravaged areas, like California, which had 50 and 60 percent collapse rates in some cases in 2008, have the heavy losses and no ready explanation—an expensive and dreadful mystery on their hands.

Even though he’s not personally affected by CCD, Wilson is ready to play sleuth on the national scene. He’s part of a USDA team established in July 2007 that involves more than 20 experts nationally, the cream of researchers, many of them also Ag Extension agents, charged with getting to the bottom of CCD and led at UT by associate plant sciences and entomology professor John Skinner.

“Our research is critical because of the value of the honey bee—all the pollination those bees do,” Skinner says. “Insect pollination is directly responsible for one out of three bites of food consumed in our country, and risks to the bee population could threaten the availability of food in the future.”

It’s not so much that anyone’s anticipating the total decline of honey bees, but the impact of continued losses could be severe, says Tennessee State Apiarist Michael Studer, who is based in Nashville. “If we don’t get a handle on it, get it stabilized, the bee decline will drive the price of food up. There won’t be as much produce, and not as much production out of the crops. Look at China—they don’t have enough bees, enough pollinators, and they’ve got people out there hand-pollinating, which would make prices here astronomical.”

And there’s always the scary thought that if even a portion of colony failures are due to pesticide accumulation in the comb, the honey bee could be sort of a canary in the coal mine—the most vulnerable, weakest link that indicates pesticide use could threaten other organisms, too.

CCD could rear its ugly head in Tennessee, too, though our economy will never become as pollinator-dependent as California’s. “All the things we think might be contributing causes to CCD, we have here,” says Wilson. “We have viruses, mites, people using all the pesticides used in large-scale agriculture. It could be possible for whatever factors combine for CCD to combine here.”

Says Skinner: “We want to avoid the perfect storm, so to speak, of having the conditions optimum for CCD to occur.”

Stung by Bee Losses

University of Tennessee entomology professor and apiary expert and grad student Michael Wilson, who’s also a bee keeper, examine frames at the UT apiary.

photo by David Luttrell

University of Tennessee entomology professor and apiary expert and grad student Michael Wilson, who’s also a bee keeper, examine frames at the UT apiary.

Last year UT lost 25 bee colonies at its apiary due to European foulbrood (pictured above), a bacterial disease. Says bee expert and professor John Skinner, who co-authored an educational article about treating foulbrood: “Prior to that, I’d only seen the disease one time in 20 years, in one colony.”

Photo by Michael Wilson

Last year UT lost 25 bee colonies at its apiary due to European foulbrood (pictured above), a bacterial disease. Says bee expert and professor John Skinner, who co-authored an educational article about treating foulbrood: “Prior to that, I’d only seen the disease one time in 20 years, in one colony.”

There’s a bustling honey booth at the Tennessee Valley Fair, with row upon row of jarred honey, and photos of veiled beekeepers wandering among white wood box hives. One of the pamphlets being handed out by farm folks staffing the booth comes from the UT Extension, and it spells out on the back, “Did You Know? If you like to eat, then you need bees!”

Despite all those jars and recipe pamphlets, they’re talking pollination, not honey. The annual value of fruits and vegetables that benefit from pollination is $118 million in Tennessee, and closer to $15 billion in the U.S.

Particularly reliant on bee pollinators in the area economy are those who grow cucurbits like squash and watermelon, and fruit. Those tiny, misshapen apples you come across can be the result of poorly pollinated blooms, for example, and blueberries also rely on honey bees. And even one cucumber requires all manner of intervention. “It takes 300 pollen grains to even set a cucumber, and 600 to set a well-shaped fruit,” says Studer. “That means you need a lot of bees for that flower to be able to get a fruit.”

Researcher Paul Rhoades removes vials of nosema spores from a tank filled with liquid nitrogen. He’s interested in how well the fungus survives low temperatures — the tank is around -250 C. Nosema is a particular threat to honey bees, striking their digestive track.

photo by David Luttrell

Researcher Paul Rhoades removes vials of nosema spores from a tank filled with liquid nitrogen. He’s interested in how well the fungus survives low temperatures — the tank is around -250 C. Nosema is a particular threat to honey bees, striking their digestive track.

Studer estimates just 25 to 30 beekeepers actively work pollination contracts in East Tennessee, and six people (including Wilson) breed bees for sale. So job losses aren’t at issue here like they are in areas such as California, where the state’s growers produce 80 percent of the world’s almond crop and require 1.5 million of the nation’s estimated annual peak of 2.5 million managed hives. But our keepers still must replace hives and hive frames, and buy new bees, which can come to about $150 per colony, says Studer. “Most of our pollinators have from 20-500 colonies, and some breeder queens can be $500 a piece, so such a high percentage of failed colonies can be a big loss.”

Swarm Troopers

Associate professor John Skinner conducts bee research but also plays an important role in getting information about the fight against CCD out to the “smartest land-grant university minds across America” through a website, eXtension.org.

photo by David Luttrell

Associate professor John Skinner conducts bee research but also plays an important role in getting information about the fight against CCD out to the “smartest land-grant university minds across America” through a website, eXtension.org.

Tennessee apiaries have suffered record numbers of foulbrood cases in the past year‹it’s a bacterium that competes for food inside honey bee larvae.

Photo by Michael Wilson

Tennessee apiaries have suffered record numbers of foulbrood cases in the past year‹it’s a bacterium that competes for food inside honey bee larvae.

John Skinner likes to joke about his first work space when he joined UT’s department of Entomology and Plant Pathology and the Agricultural Extension in 1990 as an assistant professor with a professional interest in apiculture. “They put me at a desk in the hall. Or was it a box and a chair?”

Now, 20 years later, the nation’s food supply is facing a threat from CCD, and Skinner, his assistant Wilson, and another recently graduated researcher, Paul Rhoades, are key figures in a national team convened to address CCD in 2007, the USDA-ARS Areawide Program for Improving Honey Bee Health. Skinner’s work space now? Three rooms, in a trailer-quality work shed at the corner of the Ag campus. Here, apiary puns rule, from the “Bee Happy!” sign on the door to the “It’s a bee-u-ti-ful day” scribbled on the dry-erase message board.

They’ve got a ’70s-style refrigerator inside retrofitted to act as an incubator, two microscopes, one fitted with a 2200-pixel digital lens, and lots of pieces of wood and wax sheets and sticky paper to make hives with. All three men are easy about the shabby space, and speak calmly, maybe from all those years of trying not to startle bees. Skinner has a close-cropped beard and wears a brimmed hat sometimes; he’s dapper. Wilson sports owlish glasses, worn jeans, and a short-sleeve Opie Taylor plaid shirt, Rhoades a long beard and old T-shirt. They look like unlikely candidates to be battling with a mystery disease that could threaten the global food supply, and they don’t talk about it much, but that’s the end game.

Three years into the research, the national CCD response team has not yet determined what causes these mysterious conditions, but they’re leaning toward a combination of factors, says Skinner, possibly including mites; viruses; the nosema fungus; pesticide use in the hives, on host plants, and on large-scale agrigultural enterprises in the vicinity; and poor nutrition. Research will continue into individual causes, and then proceed along to the causes in combination, until it becomes cost-prohibitive.

“Any three in combination can do it in, or maybe fewer,” says Skinner.

Wilson, who started with bees 10 years ago on his grandfather’s mini-farm a couple of years after earning an art degree at UT, is surveying the importance of native bees for pollinating crops. “We’re pretty much looking at what else pollinates, with the honey bees in trouble,” he says. He’s also studying how wildflowers planted near crops might diversify the honey bees’ diet and provide better nutrition. “Well-nourished bees produce more honey, and they’re less susceptible to the nosema ceranae fungus known to wipe out entire area colonies,” he says.

To assist Skinner, who’s also an Ag Extension agent, he’s helped with seminars on breeding bees that are mite-resistant; as a sideline, he also breeds queen bees from USDA mite-resistant stock. “To make a long story short, their queens are hygienic—they’ll remove infested brood from the colony and prevent mites from reproducing,” Wilson says. “It works really well, except the problem of getting the genes into the next generation. The USDA instrumentally inseminates the queens, but mine are open mated. With the mix of population of local honey bees, and some beekeepers near me who are not trying for the resistant genetic trait, the genes get diluted real quickly, although the daughter queens are still resistant.”

Rhoades’ study, conducted for Skinner, is aimed at providing a new solution for nosema, and, in a roundabout way, trying to determine if European pesticide policies might have some impact here. He’s looking at whether certain oil extracts made mostly in Europe might stave off nosema as promised. Since nosema (a really icky fungus that basically makes it impossible for honey bees to digest food) can only be contracted by adult bees, Rhoades originally tried to experiment with bees that were raised entirely in an incubator, where he would know if and how they reacted to the nosema. But his newsly emerged adult bees kept dying, and nine months later he’s had to tweak and start using young adult bees born outside the lab.

He’s got lots of motivation to solve the issue—his research might provide an alternative to the lone chemical treatment available for nosema. “It’s been used for a long time, and if we keep using that treatment, the parasites could become immune. If that happens, there would be no treatment at all for nosema, which would be serious.”

Photo with no caption

photo by David Luttrell

Another promising, but long-range, solution to a possible aspect of CCD is selective breeding for resistance to certain threats; like the USDA’s mite-resistant queen, which was developed in the late ’90s under a program Skinner contributed to. “If we can develop bees that have more resistance to these threats, we won’t have to use chemicals that are potential contaminants to the honey and wax,” says Skinner.

But a breeder can select each side of the parentage only once. “So you can choose the bee that’s resistant to disease because it throws out mite-infested brood, but so intense at housecleaning it can’t get anything else done,” says Skinner. “And you have to breed the paternal side as well as the queen, and she can breed with 15 drones in her life.” To shorten the time of paternal traits seizing hold, instead of the queen breeding among all the locals in a swarm, instrumental insemination is a possibility, but an expensive one.

And what all the fuss and precision means is that even a single step toward resolving CCD, selective breeding for mite resistance, may take up to 10 years before it can be introduced to beekeepers. Same with any new chemical applications, which can take three to five years to make it through trials, and another two or so to make it through USDA approvals.

Meantime, the recipe for the “perfect storm” could be assembling in our state, just as it’s hit so many others.

But that doesn’t worry Skinner; he says it can’t. “It’s true of all scientific research. You don’t just wave a magic wand. More often that not, it’s not immediately successful. You’re not going to move ahead if you let that bother you. If one idea doesn’t work, we don’t give up.”

Photo with no caption

photo by David Luttrell

***

So You Wanna Keep Some Bees?

Whether for fun or profit, for honey, or just to assist with pollination of nearby fruit trees or pumpkin patches, there are several local sources of information about keeping bees:

Knox County Beekeepers Association

Meets first Monday of the month at New Harvest Park Community Center, 7 p.m.-9 p.m.

kcbaoftn.org

UT Tennessee Beemaster Class

A series of seminars that will start in late winter/early spring.

bees.tennessee.edu/beemaster.htm

Blount County Beekeepers Association

Meets the second Monday of the month in the Blount County library, 6:30 p.m.-8:30 p.m.

blountbees.org

© 2010 MetroPulse. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Comments » 3

batjeffers writes:

I know of at least 150 lost hives this year in Scott County, and these people are not your very novice beekeepers, they have bees for years with lots of experience, going to the Oneida City park this summer in a field of white clover where as a teenager after swimming if you were barefooted you would get stung several times crossing the field where you would crush bees as you ran. i counted 3 honeybees in the entire field,being a beekeeper it makes me really sad.

TomB writes:

Hopefully native pollinators like bumblebees, moths, flies, and butterflies can take over the job. I too have noticed far fewer honey bees than in years past but quite a few bumblebees this summer.

Your comment about clovers reminds me that thanks to the quest for a perfect lawn clovers have just about disappeared from most subdivisions thanks to huge amounts of herbicide. Perhaps we are killing off their food sources at a high rate as a result.

beesforsale writes:

If you want your business to be successful, you should think wisely and take some risk. Try and try until you succeed. Anyway beekeeping is fun, theirs no reason not to enjoy it. It's like taking care of your pets. If you give them what they wan't then you can have what you need from them. Honey and money...

Share your thoughts

Comments are the sole responsibility of the person posting them. You agree not to post comments that are off topic, defamatory, obscene, abusive, threatening or an invasion of privacy. Violators may be banned. Click here for our full user agreement.

Comments can be shared on Facebook and Yahoo!. Add both options by connecting your profiles.