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Could that bee buzzing around.the blooms in your garden be the last one you’ll ever see?
Versions of this question haunt many of the world’s leading bee experts, a good number of whom were gathered at York U. two weeks back to strategize around “barcoding” the DNA of the nearly 20,000 known bee species and the estimated thousands that haven’t yet been documented.
The fact is, while much has been made of the effect of colony collapse disorder on domesticated honey bees across Europe, Asia and North America, few have grasped the disappearing act of the planet’s wild bees – an estimated 800 species of which are native to Canada, 150 in the GTA itself.
“We know bee populations have declined,” says York U. biologist Laurence Packer, who initiated the project. “There’s evidence on all continents.”
Despite common perceptions, only one bee species in Canada produces honey, and it comes from Europe. Most forage for pollen alone, without highly organized colonies, but are nonetheless responsible for a good deal of our agricultural pollination and essential to the ecology of native flowering plants, which can’t propagate without them.
Packer’s lab advocates listing two Ontario species, including the rusty-patched bumblebee (with a distinctive band on its fuzzy abdomen that looks like it was swabbed with iodine) under the feds’ Species At Risk Act.
“You can still find it in a couple of places in the U.S.,” says Packer – an appalling situation for a creature formerly ranked as Ontario’s fourth most-common bee.
One-third of the food-growing industry in Ontario (mainly growers of fruits and veggies) relies on pollinators – mostly bees – for plant fertilization. “A lot of the pollination that is ascribed to the honey bee is actually done by wild pollinators,” Packer notes.
The value of pollination for Canadian food crops is conservatively estimated at $1.2 billion a year, and research shows reduced crop yields as pollinator diversity declines. Blame that decline on a cocktail of pollution, disease, pesticides, loss of habitat and a number of factors that haven’t been explained.
Some species are known for being especially productive with certain crops. Bumblebees, for example, are widely brought to tomato and sweet pepper crops, and orchard bees to fruit trees. Matching certain bees with particular crops has been practised successfully for years. But in some cases, that may prove unfortunate managed bees, it turns out, could play a part in making the wild ones sick.
Dr. Paul Williams of London, England’s Natural History Museum, who studies the decline of bee populations as city concrete overtakes bee staples like clover, wonders if bumblebee losses in North America originated in Europe.
Williams, who was in town for the York meet, says North Americans crossed the pond recently to learn bumblebee pollination husbandry, bringing their bees along on the trip. Some of the breeds that made the trek and returned home with their keepers “have become extremely rare,” according to Williams.
“The suggestion has been made that some of these bees brought with them diseases,” he says.
If a virus has jumped continents, it won’t stay in the greenhouse for long. “These domesticated bumblebees do get out to wild bumblebees,” Packer says.
While no-one is certain what is killing so many bees, Packer explains in his writings that once bee numbers start dropping, for whatever reason, the curve very quickly gets steep.
A dwindling gene pool, he says, falls prey to a built-in tendency in bees to produce sterile males. The spiral of diminishing returns that follows is called an “extinction vortex.” The vortex unfortunately extends to the chicken-and-egg relationship between bees and plants, insuring the doom of plant species, the animals that eat them and so on.
It’s a complex biological dance, at the end of which every living thing, including humans, will be affected. The unfortunate bee talent for quick extinction makes them an excellent marker for the collapse of ecosystems. “I argue that they’re actually far better [at that] than almost anything else,” says Packer..
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One garden at a time
What you choose for your yard or balcony box can make a big difference to our local bee contingent.
According to gardening expert Marjorie Harris, the perfect garden is “a very noisy place. It should have hundreds of birds coming through. It should have millions of insects doing their jobs.”
Counterintuitively, the city is often more biodiverse – with its jumble of yards, parks and weed-grown lots – than many rural areas choked with pesticides and monocultures. “One of the reasons the city is good for bees is because different people grow different things,” says York U bee expert Laurence Packer.
Certain plants develop close relationships with particular bees. Raspberry bushes are pollinated by tiny bees that tend to nest in their hollow stems, for example.
Packer suggests tomato plants as a nice way to start a win-win partnership with bees. “Bumblebees love tomatoes, and they’re good at pollinating them,” he says.
He also advises against throwing out dry, hollow bramble stems and raspberry canes, because bees nest in them.
Harris recommends bug magnets like black-eyed Susans, trilliums, goldenrod, echinacea, bloodroot and wild ginger.
“I jam plants in there,” says Harris. “I make room for everything and everyone.”
