The Plight of the Honeybee

Billions of dollars—and a way of life—ride on saving pollinators.

A beekeeper pulls a section of honeycomb from a hive.

Photograph by Gianluca Colla, National Geographic

Jennifer S. Holland

for National Geographic News

Published May 10, 2013

Part of our weekly "In Focus" series—stepping back, looking closer.

Bees are back in the news this spring, if not back in fields pollinating this summer's crops. The European Union (EU) has announced that it will ban, for two years, the use of neonicotinoids, the much-maligned pesticide group often fingered in honeybee declines. The U.S. hasn't followed suit, though this year a group of beekeepers and environmental and consumer groups sued the EPA for not doing enough to protect bees from the pesticide onslaught.

For the last several years scientists have fretted over the future of bees, and although research has shed much light on the crisis, those in the bee business—from hive keepers to commercial farmers—say the insects remain in deep trouble as their colonies continue to struggle.

The current crisis arose during the fall of 2006 as beekeepers around the country reported massive losses—more than a third of hives on average and up to 90 percent in some cases. Bees were flying away and simply not coming back; keepers would find boxes empty of adult bees except for a live queen. No bee corpses remained to tell the tale. The losses were unprecedented and fast.

Now it's five years later, and though colony collapse disorder (CCD)—the name given to the mysterious killer condition—has dwindled in the manner of cyclical diseases, bees are still battling for their lives and their colonies are weaker than ever. The latest data, from the 2012-2013 winter, indicate an average loss of 45.1 percent of hives across all U.S. beekeepers, up 78.2 percent from the previous winter, and a total loss of 31.1 percent of commercial hives, on par with the last six years. (Most keepers now consider a 15 percent loss "acceptable.")

Unprecedented Pollinator Crisis

Why keep worrying over the fate of a bunch of pesky stinging insects? Bees in their crucial role as pollinators are paramount. Western nations rely heavily on managed honeybees—the "moveable force" of bees that ride in trucks from farm to farm—to keep commercial agriculture productive. About a third of our foods (some 100 key crops) rely on these insects, including apples, nuts, all the favorite summer fruits (like blueberries and strawberries), alfalfa (which cows eat), and guar bean (used in all kinds of products). In total, bees contribute more than $15 billion to U.S. crop production, hardly small potatoes.

No, we wouldn't starve without their services—much of the world lives without managed pollinators. But we'd lose an awful lot of good, healthy food, from cherries and broccoli to onions and almonds. Or we'd pay exorbitant costs for farmers to use some other, less efficient pollination technique to supplement the work that healthy natural pollinators could do. Plus, bee health can tell us a lot about environmental health, and thus about our own well-being.

A man uses smoke to harvest honey from a honeycomb.

Photograph by Tim Laman, National Geographic

Today's pollinator crisis, which has also hit Europe and now parts of Asia, is unprecedented. But honeybees have done disappearing acts on and off for more than a century, possibly since humans began domesticating them 4,500 years ago in Egypt. In the United States, unexplained colony declines in the 1880s, the 1920s, and the 1960s baffled farmers, and in 1995-1996 Pennsylvania keepers lost more than half of their colonies without a clear cause. The 1980s and 1990s saw various new parasites that hit bees hard; Varroa and tracheal mites became major killers, and they continue to plague hives and keep beekeepers up at night.

When CCD appeared, the USDA's Agricultural Research Service and the National Institute of Food and Agriculture joined forces to study and fight the assailant, but a half-dozen years later they still lack a smoking gun. Recent work reveals higher loads of pathogens in the guts of bees from collapsed colonies versus healthy ones—making viral infections a likely culprit.

But this isn't a case of one cause, one effect. Bee expert Dennis vanEngelsdorpof the University of Maryland likens the situation to HIV/AIDS in humans. "You don't die of AIDS; you die of pneumonia or some other condition that hits when your immunity is down," he says. Today's bee mortalities may be behaving slightly differently. "But we're pretty sure in all these cases, diseases are the tipping point" after bees' immune systems are compromised.

So what makes bees vulnerable to those diseases, what's killing their immunity, continues to be the $15-billion question.

Problems Piling Up

Zac Browning is a fourth-generation beekeeper based in North Dakota. His mostly migratory commercial operation runs about 22,000 hives in three states—meaning he trucks his bees to different locations at different times of year, renting out their pollination services to big farms like those producing almonds in California and canola in Idaho.

CCD devastated his hives a few years back, but "we've seen losses more recently from everything imaginable," he says. "Pests, parasites, pesticide exposure, starvation, queen failures, you name it."

In addition to these problems piling up, "our inputs have gone up one-and-a-half times in the last decade," he says. "We now have to try to sustain bees [with extra food] when natural food is scarce, dearth periods that didn't exist before."

Part of the problem is keepers have to boost hive numbers to meet demand, "but the carrying capacity of the environment hasn't changed." In fact, it's gone down. The amount of undeveloped land with good bee forage just isn't enough to sustain the masses, he says.

Meanwhile, studies have shown that colonies with access to the best pollens (with more than 25 percent protein plus essential amino acids), which occur in diverse plant habitats once common across the landscape, are more robust and more resistant to disease than those in pollen-poor environments.

The Threat From Pesticides

Another adversary in the bees' battle, as the EU reminds us, is pesticides. Pesticides themselves aren't necessarily a death sentence for bees—and debate rages over whether, when properly applied, these chemicals can be used safely among pollinators. But exposure to them seems to open the door to other killers.

For example, bees exposed to sublethal doses of neonicotinoids—the type the EU is banning and that are used routinely in the U.S. on wheat, corn, soy, and cotton crops—become more easily infected by the gut parasite Nosema.

Meanwhile, last year a French study indicated that this same class of chemicals can fog honeybee brains and alter behavior. And a British study on bumblebees, a natural pollinator in decline in many places, reported neonicotinoids keep bees from supplying their hives with enough food for queen production.

A man shows his hive's queen bee.

Photograph by Marcio Jose Sanchez, AP

"Honeybees are complex," says Browning. "If you reduce their lives by even just a few days, the colony itself never thrives, never reaches its maximum potential. Sublethal effects that don't kill adults outright may still render hives weak and lethargic. And those hives might not survive the winter."

What takes down the individual bee doesn't necessarily wipe out the colony, vanEngelsdorp explains. And pesticides, like other factors, do their worst when combined with other chemicals or stressors, not necessarily all by themselves. "It's synergism," he says. "One plus one may equal 10 with the right two products or insults together." (Samples of bee-collected pollen typically contain residue from numerous pesticides.) In the end, then, an immune-suppressed colony faces a downward spiral, unable to cope with stressors that weren't a problem during healthier years.

The chemicals of modern agriculture have long been vilified, and they certainly represent a vital and active line of inquiry: The number registered for use in the U.S. exceeds 1,200 active ingredients distributed among some 18,000 products, and state pesticide use records are mostly unavailable, leaving a lot of question marks. No one knows much about how low-level exposure to various chemicals over time or how various combinations affect the insects. Meanwhile, migratory colonies likely have very different chemical exposure than those who stay put. The landscape is messy.

A New Concern

In newly worrisome findings, a study from a team at Penn State has revealed that "inert" ingredients (adjuvants) used regularly to boost the effectiveness of pesticides do as much or more harm than the active "toxic" ingredients. In one study adjuvants were shown to impair adult bees' smelling and navigation abilities, and in a separate study they killed bee larvae outright.

The formulas for these other ingredients "are often proprietary information and not disclosed by the companies," says Penn State's Maryann Frazier, who wasn't an author on the study, "so they cannot be independently tested and assessed for toxicity. When [the] EPA screens pesticides for registration, they only consider the active ingredient," she says.

In addition, "there are no requirements by [the] EPA for companies to test the impacts of pesticides on immature stages of pollinators," she says, "only adults."

The EPA participated in a stakeholder conference last year to discuss honeybee health (a report is just out from that event). An EPA spokesperson declined to comment on the pending lawsuit but noted that the agency has been working to speed up its review of research related to neonicotinoids and their effect on honeybees. It is also tweaking existing regulatory practices to address various concerns including pesticide dust drift, product label warnings, and enforcement of bee-kill investigations.

Barrage of Stressors

So in addition to a changing climate and bizarre local weather systems, bees are threatened by chemical exposure in untested and unregulated combinations, disappearing foraging habitat with increasing monoculture that requires trucking bees from place to place, and fungal and viral intruders, plus the dreaded Varroa mite.

Meanwhile, nature is not sitting still. The diseases that are taking out immune-suppressed bees are quick to evolve resistance to farmers' attempts to protect their bees. "Based on our management surveys last year, not one commercial product against Varroa worked consistently," says vanEngelsdorp, citing numerous examples.

With the barrage of stressors bees face, perhaps we shouldn't be surprised that they're no longer as resilient as they once were. And honeybees, vanEngelsdorp points out, are among the most robust pollinators. The native insects, such as bumblebees, stingless bees, and flies, may be in worse shape, though their plights—and role in the ecosystem—are far less well known.

Meanwhile, the lawsuit against the EPA is just revving up (the first hearing was March 15), and scientists continue to push hard to get more information on the unregulated ingredients in agrochemicals that are proving harmful. "Unless we can get at what's actually being used on fields, we can't analyze their effects," says toxicologist Chris Mullin, a co-author of the Penn State adjuvant study. And some products, he says, "are nearly 100 percent adjuvant. Illogically, they are considered safe until proven otherwise."

Other voices have risen strongly against current land use practices. "Honeybees need habitat," Browning says. "That's any floral source with good nutrition. And that's not wheat, corn, or soy, crops that take up well over 60 percent of U.S. farmland." We've traded bee needs for biofuel, he laments, and we're paying the price.

"We also need good cooperation from [the] EPA—and from farmers and pesticide applicators—to implement and enforce best management practices," he says. Also on his wish list: a better battery of tools to effectively combat the Varroa mite, the bane of all beekeepers.

"Bee culture has adapted to fit monoculture, and that's not healthy," says Browning. "If we can instead invest in good sustainable practices in agriculture, we can still thrive."

But his confidence in the future, along with that of many of his fellow beekeepers, is declining with his hives. "We're just about tapped out," he says. "Without some real action we'll see this industry dwindle away." And as the industry goes, so go the little yellow insects that put so much good food on our plates.

Jennifer S. Holland, a contributing writer to National Geographic, wrote aboutpollinators in the March 2011 issue of National Geographic.

Original Post

Lower pollinator numbers herald crisis

A decline in the number of butterflies and bees, major contributors toward global farm output, calls for urgent conservation steps

Ananda Banerjee, ananda.b@livemint.com

Red Pierrot, Common Lime, Plain Tiger, Blue Pansy or the Common Castor may be unfamiliar names to most Indians, although it is likely that most would have seen one or more of the five—the most common butterflies found in India.

While it is unlikely that most people would notice their absence, it is almost certain that plants will—butterflies, such as these, help them reproduce.

The subcontinent has approximately 1,300 of more than 20,000 butterfly species known, said Kishen Das, a US-based lepidopterist. That’s about 6.5% of the global butterfly diversity. 

However, the problem is that around 100 of the butterfly species found in India are nearing extinction, according to Surya Prakash, a professor at the department of life sciences at Jawaharlal Nehru University. “Few are aware of the crucial pollination role the butterfly plays, which is second only to the honeybee,” he adds. 

There’s bad news on that front too.

“Our observations in the Sundarbans have established that the population of bees as pollinators is decreasing,” says K. Venkataraman, director, Zoological Survey of India​.

Pollination is the process that helps plants reproduce. From the consumption point of view, it is also the process that produces fruits, vegetables, pulses, and grains—any food, basically, that comes from a plant.

Around 70% of all food crops are pollinated by insects, according to the Food and Agriculture Organization. In Europe, the proportion is 84%. While no corresponding data is available for India, there’s nothing to suggest that food crops here are pollinated by other means. This means that a decline in the number of pollinating insects could have catastrophic effects.

 “If human beings were to disappear tomorrow, the world would go on with little change, but if insects were to disappear, I doubt the human species could last more than a few months,” wrote noted American biologist E.O. Wilson.


The impact of some insects becoming extinct isn’t top-of-the-mind in a country where even conservation efforts are skewed towards large mammals, or mega-fauna, as Isaac Kehimkar, general manager (programmes) at the Bombay Natural History Society​ and author of The Book of Indian Butterflies, terms it. “Lack of knowledge and obsession with mega-fauna is killing entomology as a subject. It has become professionally unsustainable today as there is a fight for the same set of funds which inevitably go to the tiger or one of the mega-fauna species,” he says.

To be fair, the emphasis on conserving pollinating insects is relatively recent, even in the US. These insects not only support humanity, but also maintain diversity in an ecosystem. “Though there has been a growing appreciation for the ecosystem services provided by pollinators, it is only recently, when farmers in the US started finding their bee colonies missing, that people started wondering about what might happen to the world’s food production in the absence of bees,” says S. Ramani, project coordinator, All India Coordinated Research Project on Honey Bees and Pollinators. “The expected direct reduction in total agricultural production in the absence of animal pollination has been estimated to range from 3% to 8%, showing that agriculture has become more pollinator-dependent. It has been suggested that we may be in the middle of a global pollination crisis.”

If no one has noticed it is because “not a single bee has ever sent you an invoice”, says investment banker and environmentalist Pavan Sukhdev. In his book, The Economics of Ecosystems and Biodiversity, Sukhdev puts the worth of insect pollination at $200 billion (around Rs.10 trillion today) a year, or 10% of the value of the world’s agricultural output.

Still, Indian research isn’t conclusive enough to establish a so-called pollinator crisis that is separate and distinct from the general decline in biodiversity, which is a global phenomenon. Even “in Europe, a region better studied than most, about 250 plant species are grown as crops. Of these, about 150 are thought to be insect pollinated, but for most we do not know which insects pollinate them, or whether yields are being limited by inadequate pollination”, wrote Dave Goulson in Bumblebees: Behaviour, Ecology and Conservation.

What is clear is that some pollinator species are under threat.

A report put out by the United Nations Environment Programme says: “When large habitats are fragmented into small isolated patches, food sources become scarcer for resident animals. Populations may then decline to the point that they are no longer able to benefit plants. As certain wild pollinators need undisturbed habitat for nesting, roosting, foraging and sometimes specific larval host plants, they are very susceptible to habitat degradation and fragmentation in particular. Human activities have impacted the landscape through fragmentation, degradation and destruction of natural habitats and the creation of new anthropogenic ones.”

To act on this information, people, especially policymakers, will have to increase their awareness of insect conservation, which is not easy because even basic science on insects is scarce. Even today, most species are undescribed and the distribution of described species is mostly unknown. To boost the public profile of insects, experts recommend “better public information and marketing”, including greater use of “red lists” of threatened species, and making sure insects are addressed in environmental impact studies.

In other words, “Save the tiger, sure, but also spare a thought for the Indian honeybee.”


Full Story

Breezy Love, or the Sacking of the Bees

By OLIVIA JUDSON

Olivia Judson on the influence of science and biology on modern life.

Birds do it. Bees do it. Beetles, bats and light summer breezes do it.

I refer, of course, to that raunchiest of sex acts: the pollination of flowers.

Ruby Washington/The New York Times SEDUCTION Bee and flower meet.

When it comes to sex, plants have more headaches than the rest of us. One problem is that they can’t travel about to find a mate — they are, after all, rooted to the spot — so they have to depend on intermediaries to bring egg and sperm cells together.

For mosses and ferns, the intermediary is water. For conifers like pine trees and cypresses, the intermediary is wind. But for most flowering plants, the intermediaries are animals.

Flowering plants are the largest, most successful group of plants on the planet today. There are thought to be more than quarter of a million different species — nearly 10 times more than all the other types of plants added together. (To put things in perspective, the number of living species of fish, amphibians, reptiles, birds and mammals combined is less than 58,000.) The flowering plants include roses and waterlilies, grasses and oak trees, tulips and orchids. They include, in short, most of the plants that come to mind when one thinks of vegetation.

It was not always thus. Before the mid-Cretaceous, 100 million years ago or so, flowering plants were scarce: conifers and their relations ruled the landscape. But then, for reasons that are not well understood, flowering plants upstaged all others, and the Earth came into bloom.

Flowering plants were not the first to seduce animals into spreading their pollen for them. Fossils suggest that some earlier groups of plants, now extinct, had evolved a dependency on insects like scorpionflies. Nonetheless, the earliest flowers appear to have been pollinated by insects, and the full-scale blossoming of flowering plants coincides with the rise of animals as go-betweens. Bees, for example, buzzed onto the scene with flowering plants; the evolutionary history, and success, of both groups is intimately linked.

Librado Romero/The New York Times

The appearance of flowering plants brought a new flamboyance to the planet. Flowers pollinated by animals tend to be big and colorful; they often smell. (To a human, flowers pollinated by bees typically smell pleasant; flowers pollinated by flies tend to smell foul, like rotting meat.) Often, flowers offer something for the animal to eat — a sip of nectar, perhaps. Sometimes, they provide heat.

(One plant that heats its flower is Philodendron solimoesense, an Arum from the South American tropics. In doing so, it turns itself into an assignation hotel for scarab beetles. The beetles arrive in the evening, spend the night feeding and mating, spend the morning recuperating and head off to a new flower later on — complete with pollen from their host. Sure enough, the heat saves the beetles energy. Beetles in a heated flower don’t have to use as many calories to keep warm as they would if they spent the night outdoors.)

Yet, from time to time, flowering plants abandon their animals, evolving instead to throw pollen to the wind. Wind-pollination — if you’re a vocabulary fiend, the technical term is “anemophily,” meaning lover of wind — has evolved at least 65 times in flowering plants, and around 10 percent of the species do it. Indeed, as I mentioned last week, many grasses are pollinated by the wind.

It’s not clear what causes this transition, though there are several ideas. One is that it happens in plants that, although generally pollinated by insects, already have a small capacity for wind pollination — small, light pollen grains, and flowers that can, in principle, catch pollen if it floats past on a breeze. Then, the balance between insects and wind can easily shift. In a tropical forest, for example, the advantages of insects are great: they provide highly targeted pollen-delivery in a complex milieu. But in big open spaces, the wind may do a better job — especially if the climate is inhospitable, and insects are few. Such circumstances may cause a shift away from traits that lure insects, and enhance those that seduce the wind.

A plant that has sacked bees or other insects can make its flowers smaller, less colorful and more aerodynamic. Liberated from the expense of making nectar, it can make more pollen instead. A bee, after all, can only carry so much pollen at once. The wind is not so limited.

And wind-pollinated plants tend to produce huge quantities of pollen. Whereas animal-pollinated plants produce a median of 3,450 pollen grains for every ovule, wind-pollinated plants produce almost 10 times as much. No wonder wind-pollinated plants are the chief causes of eye-itching, nose-tickling human misery. (It’s not just the anemophilous flowering plants that are to blame, though. Wind-blown cypress pollen is a major cause of allergies in some parts of the world.)

This massive production of pollen is usually put down to the inability of wind to make reliable deliveries.

Librado Romero/The New York Times

Charles Darwin himself suspected the wind of being a fickle and inefficient messenger, and that view has largely held until this day. But there is little actual evidence that wind-pollinated plants have more difficulty getting themselves fertilized than other plants do. (Indeed, plants seem adept at plucking pollen of the right species out of the breeze. How they do this isn’t known.) Moreover, in animals, large numbers of sperm tend to evolve when competition between different males to fertilize a female’s eggs is fierce. In many wind-pollinated species, plants flower all together, and for a brief time. Perhaps wind-pollinated plants face greater competition from their rivals.

But whatever the causes, I’m glad that most plants have not sacked their bees. In a world pollinated only by gusts and breezes, spring would be less beautiful. And, for many of us, it would also be more tortured.

Story and additional Notes