Silent Swarm

May 2, 2012 • Features, Print, Slideshow, The Farm • Views: 912

by Aaron Gertler:

Six years ago, the bees stopped waking up. As winter turned to spring, beekeepers across the United States found their dormant hives devastated. Some lost 90 percent of their colonies, and the insects that remained were weak and listless. The United States Department of Agriculture leapt into action, but the losses persisted; according to 2009 and 2010 reports, the American bee population dropped by 29 percent and 34 percent respectively.

By winter 2007, the catastrophe had spread to the nations of Europe. The National Association of German Beekeepers reported a quarter of all hives dead, and Italy lost nearly half its colonies. The international media quickly christened the crisis “colony collapse disorder” (CCD), but beekeepers resisted, claiming the phrase glossed over the diverse causes behind the industry’s devastation. Was the parasite Nosema creeping into colonies and snuffing out the swarms? Had the Varroa destructor mite annihilated insects vital to the pollination of countless crops, from cranberries to canola oil? Or were human farming techniques and pesticides primarily to blame?

The pesticide problem, though not the sole cause of bee deaths, is easier to control than the spread of parasites and has become the main focus of several European governments. Neonicotinoids, the world’s most commonly-used class of insecticide, came into use in the early ’90s to protect Europe’s corn, rapeseed, and other plants, but suspicion regarding its impact on pollinators wasn’t far behind. Observational studies showed bees in areas heavy with insecticide residue growing strangely apathetic; they failed to care for developing young and got lost trying to find their way back to their hives from nectar-gathering expeditions. Liona Rowan, an organic beekeeper from Texas, described the insecticide’s effects as a kind of “bee AIDS”—weakening their natural immunities so they cannot resist many of the not so-deadly problems that naturally occur in bee populations

France banned the application of imidacloprids, one substance in the neonicotinoid class, to sunflower and corn seeds before 2000, and Slovenia followed suit in 2003, but Germany, where Bayer, the world’s foremost pesticide manufacturer, is headquartered, did not do the same until 2008. However, each nation continues to permit the spraying of grown plants precisely where bees prefer to forage.

Bayer representatives did not respond to inquiries, but their website claims there has been “no demonstrated effect” of neonicotinoids on bee health. In 2011, multiple American and European studies claimed otherwise.

The United Kingdom hasn’t yet restricted the use of neonicotinoids. But in March 2011, as evidence piled up from France to the Netherlands that such insecticides made bees far more vulnerable to the fungal disease nosema, Professor Robert Watson of the British Department for Environment, Food, and Rural Affairs ordered an investigation of published research into the substance. A year later, the March 2012 issue of Science published a pair of studies on neonicotinoids, one of which came from Dave Goulson, a biology professor at Britain’s University of Stirling, who claims that he may have “put the nail in the coffin” for the chemicals. In a press release, Goulson showed that exposure to even low levels of neonicotinoids reduces the production of new queen bumble- ees by up to 85 percent. Since queens are responsible for founding new hives in springtime, multiple seasons of insecticide exposure will seriously diminish bumblebee populations in cultivated areas, leaving fewer around to pollinate. Rosemary Mason, an independent observer who runs a nature reserve in the UK, feared even greater losses to come. “Unless we get [neonicotinoids] banned,” she told me, “we’ve no hope.  Biodiversity is being hammered.”

Another deadly pattern emerged from one of Goulson’s earlier studies (2004-10).  Wild bees normally spend most of the year gathering nectar from every flowering plant in the vicinity. When bees live in monocultured fields, however, only one form of flower is available; it blooms for a few short weeks, bees enter a feeding frenzy and breed at full capacity, then the flowers close and starvation ensues. Whatever bees remain are easy prey for parasites and diseases. Goulson thinks this issue might be solved easily by devoting a fraction of farmland to flowers to leave colonies as robust as ever.

Goulson hopes to channel his fellow Britons’ affinity for nature into another lifeline for Britain’s bumblebees. A passion for the outdoors has already convinced 6,000 civilians to answer Goulson’s call for “keen amateur bee enthusiasts “to patrol their stretch of countryside and report local bee activity to the Bee Conservation Trust, an organization Goulson founded in 2010 to track colony health around the country. Thanks to programs like the Trust and the BeeBase program of the British Beekeeping Association (BBKA), scientists in the UK know more about their nation’s bumblebee population than ever before. However, unless researchers keep pace with the swarm of other threats to colonies, information alone won’t stop the dying.

One such threat is the parasitic mite Varroa; the most prominent factor behind the tripling of Ontario’s death rate in 2007, which began plaguing Canada shortly after the U.S. collapse. The mite worries Rod Scarlett, Executive Director of the Canadian Honey Council, not only because it can wipe out hives in a week, but also because of its incredible adaptability. “We always need to have a new treatment in the queue,” he said, since the wandering habits of bees allow chemical-resistant mites to spread quickly from hive to hive.

Until recently, a lack of attention to research also plagued Britain. Tim Lovett, former president of the BBKA, called the relatively small market for bee treatments “a great handicap” to the timely creation of new medicines. Although bees themselves don’t bring riches to their keepers, they contribute roughly 150 billion dollars in annual value to global agriculture, with nearly half a billion for just eight of the dozens of British crops they pollinate, according to Lovett. The British government’s contribution to bee research, a mere thousandth of that annual total, incensed the nation’s beekeepers and drove hundreds of them to march on Downing Street in their trademark white isolation suits to present a petition signed by 140,000 nervous Britons at the height of the crisis, in November 2008.

The British government’s resulting pledge–nine million pounds for research and development–funded Goulson’s work and that of many more apiologists. But studies that outline the causes of death fail to propose any policy-based holistic solution to the shrinking bee population.  Mass bee die-offs have been seen since before pesticides came into wide use; according to University of Delaware entomology professor Deborah Delaney, “fall dwindle” and “disappearing disease” predate CCD by decades.

Delaney also admits that conditions outside the wild are rougher than ever before. “Some of the really scary things from the 1950s have been banned, but this is the first time we’re seeing hive walls themselves actually permeated with chemicals.” Britain’s actions may be too little, too late; the UK’s overall bee population has been halved since 2006, and the 2006 numbers were half those of the early 1900s. Each die-off is more severe than the last, and the most recent crisis involved more factors in more countries than ever before. After the next wave of mutant mites and opportunistic diseases, will there be any bees left to save Britain’s broad beans and Canada’s canola?

If, as Mason and Rowan think, bees become mostly unusable as pollinators on pesticide-soaked land, the consequences will be dire. Without bees’ activity, the BBKA estimates that we’d lose a third of the food we consume daily. Common plant species wouldn’t go extinct, but prices would skyrocket for canola and sunflower oil, fruit, vegetables, nuts, coffee, the list goes on. Certain popular crops, however, rely on pesticides to thrive as much as others rely on bees. Wheat, rice, and corn don’t require outside pollinators and account for the majority of global calories. Suspending pesticide usage on the world’s most productive farmland could lead to billions of dollars in lost crops. Pesticide use in Sichuan, China, for example, led to total bee extinction, forcing farmers to hand-pollinate their apple trees in a process far less efficient than letting bees do the work. Farmers lose either way.

If bees are someday relegated to organic gardens and sheltered honey production, however, humanity, as always, will find a way to cope. This February, a team of Harvard engineers revealed their newest creation: an assembly-line process that churns out bumblebee-sized flying robots.

The first possible use listed for the machines: “autonomously pollinating a field of crops.” In a world of unnatural plant protection and international exchange, unnatural nature might become an inevitability.

Aaron Gertler ’15 is in Timothy Dwight College. Contact him at aaron.gertler@yale.edu.

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