What’s killing our honeybees?

What’s killing our honeybees?

Activists blame neonicotinoids but not all scientists agree.

The question shifted from academic to urgent this spring as the implications of losing a third of the world’s best pollinators every winter began to hit home. In California’s Central Valley—home to 80% of the global almond supply—farmers faced a shortage of commercial honeybees critical for producing a healthy crop, paying triple what they paid a decade ago for the colonies they could get. In Pennsylvania, U.S. Senator Robert Casey warned there weren’t enough bees to pollinate the state’s vast apple, pumpkin and potato crops. In Maine, wild blueberry plants sat barren without pollen to make their fruit flower.

One Rhode Island Whole Foods pulled half its produce off the shelves for a day to il­lustrate the bleak future that may lie ahead. The USDA chimed in with an alarming re­port in May predicting that, if honey bee populations continue to plummet, higher food prices will inevitably follow.

Enter a growing chorus of activists—in­cluding the Center for Food Safety, the Sierra Club, and the Center for Envi­ronmental Health—pointing to a single culprit in the mysterious case of the disap­pearing bees. They claim a novel class of systemic pesticides called neonicotinoids is to blame for a disturbing phenomenon called Colony Collapse Disorder, and that the United States should follow the Euro­pean Union’s recent ban. But some bee re­searchers say it’s not so simple.

“I have been totally disillusioned by the tactics of the extremist left wing. They are pursuing an agenda that is not data based,” says Dennis vanEngelsdorp, PhD, an apia­rist with the University of Maryland who has spent decades studying honey bee health. “Do neonicotinoids play some role? Possibly. But it’s not the only thing. By just focusing on one thing we will not get the solutions we need.”

Why bees matter

Watch a honeybee alight upon a flower, and you may be witnessing a conception. As the bee licks the flower’s inner circle, sucking up sweet nectar for fuel, it leaves behind pollen (essentially plant sperm) that it in­advertently picked up at its last flower stop. When plant pollen meets plant ovary, baby plant is born. “The baby is an apple or a nut or some other kind of fruit,” explains be­havioral ecologist and bee researcher Noah Wilson Rich, PhD.

Honeybees pollinate about 130 crops, and are responsible for one in every three bites of food we eat, according to the USDA. They generate $15 billion in increased crop value each year. Some crops, like almonds, rely almost exclusively on bees for pollina­tion. Each February, beekeepers flock to California’s Central Valley, hives in tow, to unleash 1.5 million colonies (nearly half the U.S. total) on 760,000 acres of almond trees. From there hives are often trucked elsewhere, to pollinate apples, berries and other crops. Native bees, also in decline, and moths help with pollination but farm­ers tend to prefer honeybees from commer­cial beekeepers because they are so prolific. “One honeybee hive has tens of thousands of individuals that can go out and pollinate tens of thousands of flowers in a day,” says Rich, whose company Best Bees provides hives and uses proceeds to fund research.

In 1940, there were 5 million colonies in the United States. Today, there are half that, according to USDA. In the past few years, colonies have declined at a rate of 30% per winter. “We are one poor weather event or high winter bee loss away from a pollina­tion disaster,” warned USDA bee researcher Dr. Jeff Pettis in the May report.

Disease, drought, habitat loss, and in­festation by invasive varroa mites have prompted die offs periodically but, in 2006, beekeepers began to discover something different. Hives that were healthy days be­fore were turning up empty. “The honey is there. The queen is there. The hive is intact. Everything looks cool, but there are no bees,” says Rich, describing what has been dubbed Colony Collapse Disorder. “It’s a who-done-it mystery.” Among the top sus­pects: neonicotinoids.

A systemic killer?

Neonicotinoids, or neonics, were first reg­istered for use in the 1990s, billed as a safer alternative to organophosphates and other pesticides sprayed on plants. Instead, these “systemic insecticides” are often ap­plied to the seed and get inside the plant (including its nectar and pollen), serving as a neurotoxin to sap-sucking and leaf-chew­ing insects.

It wasn’t until 2004-2005 that compa­nies like Monsanto began routinely pre-treating their genetically-engineered corn seeds with neonicotinoids as an additional protection against pests. Many suspect this happened because pests were becoming immune to crops genetically engineered to resist them. Regardless, a year later, reports of CCD hit the news.

“As early as 2008, we were talking about CCD likely being linked to neonicotinoids, but our government refused to recognize it,” says Chensheng “Alex” Lu, an associate professor in the department of environ­mental health at Harvard School of Pub­lic Health.

In 2012, Lu published a paper in the Bul­letin of Insectology, reporting on a nine-month study looking at bees exposed to a neonicotinoid called imidacloprid. Lu theo­rized that CCD emerged as a result of bee­keepers switching to cheaper high-fructose corn syrup as a food source for their bees. (Bees can also be exposed to neonics by for­aging on crops).

For his study, he fed neonic-containing HFCS to 16 healthy hives for 13 weeks. Go­ing into winter, they looked healthy. But 23 weeks later, 15 were void of bees. In the control group only one hive died. “We were the first to publish data showing that if you feed hives a small amount of neonic­otinoids, what happens resembles CCD. It changed the discussion,” says Lu.

By 2013, numerous other studies suggest­ed neonics were at least partly to blame for CCD. In January, the European Food Safety Authority concluded that neonics pose an unacceptably high risk to bees. Five months later, the EU banned neonics for two years on crops attractive to bees. In March, the Center for Food Safety joined beekeepers and environmental groups suing the Envi­ronmental Protection Agency for its “fail­ure to protect pollinators from dangerous pesticides.” It called on EPA to suspend the registration of neonicotinoids, calling them “clear causes of major bee kills and signifi­cant contributors … to CCD.”

Not surprisingly, Bayer CropScience and Syngenta—both neonic makers—are cry­ing foul. “Banning these products would not save a single hive,” said Syngenta COO John Atkin in a prepared statement. Jerry Hayes, a veteran beekeeper now heading up Mon­santo’s newly formed Honey Bee Health Advisory Council, isn’t convinced neonics are to blame, and calls them a vast improve­ment over pesticides of the past. “I remem­ber when I was a kid in the country and farmers had to spray acre after acre with all sorts of scary stuff,” says Hayes. He estimates that rather than spraying 44,000 square feet of plants, farmers can now spray 44 square feet of seed with something with “very low mammalian toxicity that kills bad bugs.”

Jessica Shade, PhD, director of science programs for the nonprofit Organic Center, sees it differently. “Instead of treating prob­lems that actually exist, you are treating all seed for problems that may or may not arise,” she says, arguing that chemical-free integra­tive pest management techniques are a safe and effective alternative. She wants neonics banned. “I think it will come down to a polit­ical battle. It’s only a matter of time before we realize that they aren’t as safe as we thought.”

A multi-pronged approach

Neonics probably play a role in the recent bee decimation, vanEngelsdorp believes, perhaps leaving them more vulnerable to varroa mites, or exacerbating the nutritional deficiencies bees already face as a result of dwindling wild land for foraging. But he has concerns about Lu’s study design and claims he hasn’t seen “solid data” showing neon­ics are to blame. He fears that if the United States hastily bans the pesticides, farmers may replace them with something even worse for bees.

“We need to take a much more compre­hensive approach,” vanEngelsdorp says. That means finding better treatments for varroa mites, urging town governments to stop us­ing neonics and other harmful chemicals for landscaping, and providing incentives for farmers and cities to set aside uncultivated land where wild flowers sprout and bees can forage. “Why do we have mowed lawns be­side the highways when we could have bee food?” he says.

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