Fight of the Bumblebee

South of Detroit and Windsor, sandwiched between Lake Erie and Lake St. Clair, the flat lines of Essex County farmland carve the southern tip of Ontario into tidy rectangular parcels of fertile, well-drained soil. When you approach Leamington from Highway 401, it is difficult to imagine this area as the nearly impenetrable forest it once was, or that the fires lit by would-be farmers to clear the land once burned so brightly they could be seen 500 kilometres west in Chicago. Today the aerial view looks more like a semi-industrial park, because the area is dominated by gunmetal grey–framed greenhouses. With some 355 hectares under greenhouse vegetable production, more than anywhere else in North America, the region’s output is larger than the entire industry in the US, and growing much faster than other types of agriculture.

Like many small counties with something to prove, the area has several nicknames: the Sun Parlour, the Tomato Capital of Canada, the Greenhouse Capital of North America. Over a century ago, H. J. Heinz set up a Canadian operation here, and as increasing numbers of Italian immigrants settled in the area its specialization in tomatoes was assured. Fields upon fields are still grown for canning and processing into Heinz ketchup, and the bulk of the county’s field crop is destined for processing. But tomatoes that end up in cans, sauces, and ketchup fetch lower prices than those grown in greenhouses, which command some of the highest prices in the produce section, especially when they turn up, unblemished and vine ripened, in the dead of winter.

The commercial greenhouse is a relatively new development. Some desultory production was done under glass at the turn of the twentieth century, but it didn’t take hold until the end of World War II, when waves of Europeans arrived in Canada. Among agricultural immigrants, the largest group was Dutch, many with ties to the Netherlands’ pioneering greenhouse growers. And they kept coming: by 2001, 23 percent of Canada’s immigrant farm population was Dutch. Their timing was impeccable. Until the early 1990s, tomatoes were costly to produce under glass, because growers had to painstakingly pollinate, or “buzz,” the flowers using manual vibrators. This was prohibitively ex- pensive, and far less effective than the work done in open-air tomato fields by wild bumblebees, which instinctively visit the flowers at just the right time.

Methods for managing bumblebees were developed in Manitoba in the 1960s by scientists Chris Plowright and Cam Jay, but it took foreign entrepreneurs to make the research profitable. In 1987, Biobest, a Belgian company that specializes in sustainable crop management, produced the world’s first commercially viable bumblebee pollination system. This breakthrough had profound effects on greenhouse agriculture. European farmers could now mail-order colonies of bumblebees in cardboard boxes that looked remarkably like the ones in which your accountant stores tax files. (The boxes vibrate and buzz alarmingly when you pick them up, and it took postal workers some time to get used to them.) By 1995, Biobest had set up operations in Leamington, and had begun to work on domesticating and breeding a local native bumblebee, Bombus impatiens, for the North American greenhouse market.

About 95 percent of commercial bumblebees sold worldwide now end up in tomato greenhouses. Richard Ward, the bleached blond managing director of Biobest Canada, attributes the sharp global increase in greenhouse farming to the success of managed bumblebees. His company sends them across Canada, the US, Costa Rica, the Caribbean, and, until recently, Mexico, where he oversaw the launch of a second North American production facility. Managed bumblebees from Biobest and its main competitor, Koppert, a Dutch company that runs a Canadian subsidiary out of a Toronto suburb, are used by farmers in more than fifty countries, the latest being China. The bees are increasingly used for open-air field work, too, as honeybees become more scarce and expensive. Tellingly, the front cover of a recent UN report on the honeybee crisis features a close-up of a mite piggybacking on a honeybee; a healthy bumblebee, a picture of hope, graced its final page.

Greenhouses represent modern farming at its most intensive and controlled extreme: the capital investments and inputs are much more expensive, and the yields much greater (up to ten times higher than in the field), but so are the risks for pathogens. These are highly controlled environments, microcosms where farmers can control temperature, light intensity, atmospheric car- bon dioxide levels, and in some cases humidity, to produce the best possible crops. Meanwhile, the warm, humid conditions that make plants grow also promote the many pests that prey on them. Inside the greenhouse, as in Paul Kelly’s hives, this poses a challenge: how do you keep parasites at bay without killing off the bees? Most greenhouse growers rely on “integrated pest management,” meaning they balance pesticides (which can quickly build up residues if overused) with biological controls, releasing “good bugs” to kill off the “bad bugs” (such as white fly) that can blemish the fruit or weaken the plants. When Ward started at Biobest in 2000, biological controls accounted for just one-third of the company’s sales. In the years since, bumblebee operations have more than tripled, but biological controls have grown even faster, now representing two-thirds of Biobest’s sales.

As Ward showed me around one of the greenhouses the company services, he pointed to the vents. Managed bumblebees can escape through them, carrying with them diseases bred inside, and they are highly motivated to do so. “Bumblebees hate tomato pollen,” he said, with the faintest trace of a Barbadian accent. When greenhouse operations multiplied in the 1990s, many wild species began to decline. Sheila Colla and other scientists hypothesized that the wild bumblebees might be dying from pathogen spillover; managed bumblebees could be infecting their wild cousins. In the mid-2000s, she did further research in Leamington and discovered that wild bumblebees near greenhouses indeed exhibited higher pathogen loads. (Japan helps prevent this by legally requiring greenhouse growers to use netting, which makes it harder for the bees to escape.)

Colla has now co-authored two papers that examine the pathogen spillover hypothesis. The second, published last year, concluded that while there was some evidence to support the premise, it alone could not explain the mysterious and widespread dis- appearance of the rusty-patched bumblebee. The same was true for habitat loss and pesticides: although both have well-established negative effects on bee colonies, neither can be pinpointed as the sole cause, given that declines have occurred in such diverse settings. Colla is collaborating on another report that will investigate how climate change has affected bumblebees. As with honeybees, the most plausible explanation for their decline is that multiple stressors are working in deadly combination; there may be no single culprit.

Extinction, as Darwin saw it, was a fact of life, a fact of nature — and proof of his new theory. As some species adapted and evolved, he surmised, others would disappear, in what he saw as the endless struggle for existence: natural selection. “If we forget for an instant, that each species tends to increase inordinately, and that some check is always in action, yet seldom perceived by us, the whole economy of nature will be utterly obscured,” he wrote.

We cannot prevent all extinctions. For one thing, there isn’t enough room on the planet for the numbers of species living here to increase indefinitely. But this is not to say we should not be alarmed by the widespread decline of these important pollinators, or by our unmitigated reliance on one managed species. Sichuan, China, no longer has any bees to pollinate the orchards, and the work must be done painstakingly, by hand.

We still know so little about the creatures with whom we share this planet — and we may never know, because they are disappearing faster than we can learn about them. We say there are 20,000 species of bees, but those are just the ones we have identified so far; another 10,000 may remain to be discovered. When I visited Laurence Packer’s laboratory in Toronto, one of his graduate students told me about two new species he had identified while writing his master’s thesis, a phone book stack of papers held together with a single metal ring, ready for binding; he had just heard that another had been found on the West Coast earlier in the summer.

As new species are discovered and old ones disappear, taxonomists must now act as both christeners and obituarists, to borrow a phrase from Richard Fortey, a former senior paleontologist at the Natural History Museum in London, UK. He compares taxonomy to a dictionary: necessary if we are to read and understand the book of life. I’m not so sure. This may be no more attainable than the Platonic ideal of Newton’s universe, one that runs like clockwork and was once believed, if only we could understand it, to offer us a predictable future.

Perhaps the greatest threat to the bees — and to us, for that matter — is hubris, and the misplaced confidence that so much control over our environment has given us. Perhaps we have only understood a part of Darwin’s theory of natural selection, believing survival of the fittest to mean survival of the fittest species — humanity — and overlooking how much we depend on the many other creatures that make up the web of life. No species, not even our own, can exist in a vacuum. Even the greenhouse has escape vents. Co-evolution, not evolution, is the name of the game.

In his latest book, The Social Conquest of Earth, E. O. Wilson posits a new, highly controversial reading of evolutionary theory that accounts for the success of so many social animals and the many species of bees that form colonies. He believes that the struggle for existence happens on many levels. Genes may be selected in ways that benefit the individual and its kin, but they are also selected in ways that benefit the social group and the individual’s participation in it. The interests of the individual are often at odds with those of the group. How they compete, he argues, defines the human condition, and the better and worse angels of our nature. For bees, however, the interests of the group tend to outweigh those of the few, whose survival is best assured by that of the group. When I asked Ernesto Guzman why he chose to devote his life to bees, his answer surprised me.

“I got hooked on bees when I read about their behaviour,” he said with a wide, beatific smile. (It’s easy to imagine him wearing a priest’s collar in another age.) “As a teenager, I wondered why we couldn’t be more like the bees. They sacrifice their lives for the good of the community.”

The day I visited Packer’s lab was the day after Hurricane Sandy blew through Toronto. The damage was negligible compared with the devastation on the eastern seaboard. Whole populations had been displaced, and not just of people: a songbird that should have been in Central or South America lay dead on my driveway. Earlier that morning, I had walked by a neighbour’s house and seen a massive oak that had split in two, one trunk crashing into the house to the east, the other hitting the one to the west. Blind luck had protected the tree’s owner. In an age in which we control so much, it is tempting to forget our frailty. We may plan, but nature will have the last word.

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