Where Would We Be Without Bees Doing Their Essential Work?
We always thought that humble bumble bees, like some politicians, made a lot of noise, but didn’t do much good. Not so. They are described as “agriculture’s key player” for the pollination of important crops. And they’re dying as habitats get warmer. The honey bee has been taking a beating too. We’ve reported on this before and the situation appears to getting worse. Reports from the US say both branches of bees are having problems coping with a changing climate, parasites, disease, as well as nasty pesticides. Read More
Straits Times (11 July 2015):
MIAMI • Bumblebees are struggling to adapt to global warming and they are simply dying rather than migrating northwards to cooler climes, said a study that raised new concerns about these important pollinators.
The report in the journal Science on Thursday is the first of its kind to point to the role of climate change in worldwide bee decline, which until now has largely been blamed on pesticide use, parasites, disease and loss of areas for habitat.
“Picture a vice. Now picture the bumblebee habitat in the middle of the vice,” said lead author Jeremy Kerr, a professor of macroecology and conservation at the University of Ottawa.
“As the climate warms, bumblebee species are being crushed as the ‘climate vice’ compresses their geographical ranges,” he added. “The result is widespread, rapid declines of pollinators across continents, effects that are not due to pesticide use or habitat loss.”
Bumblebees help pollinate plants, wildflowers and fruit trees as well as important crops like blueberries and tomatoes, providing an invaluable service to agriculture and wildlife.
“Wild bumblebees are important pollinators of agricultural crops such as blueberry, apple, pumpkin and tomato, and declines in this ecosystem service of pollination could lead to lower crop yields and higher food costs, with consequences for both our food supply and the economy,” University of Vermont biologist Leif Richardson said.
The decline in pollination could make food more expensive and some crops harder to grow, researchers said.
By examining nearly a half million records from museums and citizen scientists on 67 bumblebee species in North America and Europe beginning in 1900, researchers were able to track changes in the bumblebees’ range over time. They found that bumblebees have lost as many as 300km of their historical southern range in North America and Europe.
“This is a huge loss, and it has happened very quickly,” said Professor Kerr.
“We are looking at rates of loss of about 9km per year from those southern areas,” he told reporters.
Meanwhile, bumblebees are “generally failing” to move north and are instead going locally extinct in some areas.
“They just aren’t colonising new areas and establishing new populations fast enough to track rapid human-caused climate change,” Prof Kerr said.
The failure of bumblebees to adapt is in contrast to the behaviour of butterflies, which have been shown to change their migration patterns in response to warming temperatures.
Ways to help the bees survive should include reducing global greenhouse gas emissions, as well as helping them establish populations in northern latitudes, a process known as assisted migration, researchers said.
Markham Heid for Time (15 April 2015):
Beekeepers continue to grapple with historically high death rates. And now something’s up with the queens.
From almonds to cherries, dozens of food crops are partially or totally dependent on honeybee pollination. And while media attention has waned, there’s still reason to worry about the country’s smallest and most indispensable farm workers.
Bee researchers first reported massive die-offs back in the 1990s. But the plight of the honeybee didn’t truly buzz into the national consciousness until the spring of 2013, when data revealed the average beekeeper had lost 45% of her colonies the previous winter. A mysterious phenomenon
Jump to 2015. While last winter’s bee death data won’t be published for a few more weeks, things appear to be “status quo,” says Dr. Greg Hunt, a honeybee expert at Purdue University. Unfortunately, the status quo is grim. “We’ve been seeing about 30% loss in an average winter,” Hunt says. “The winter before last was particularly bad and got a lot of attention, but things have been bad for a while.”
Dr. Dennis vanEngelsdorp—a University of Maryland entomologist who helps collect and publish the winter death data each spring—says there are three “primary drivers” of honeybee loss: The varroa mite, pesticides and poor nutrition. He doesn’t hesitate when asked to name the largest threat to bees: “I’d get rid of the varroa first.”
Varroa mites, properly (and frighteningly) named Varroa destructor, likely migrated to the U.S. sometime in the 1980s. They attach to a honeybee’s body and suck its blood, which kills many bees and spreads disease to others. The varroa can jump from one colony to another, wiping out whole populations of honeybees, vanEngelsdorp explains. There are treatments that combat the varroa. But many small-scale beekeepers don’t use them. “That’s bad, because they can spread mites to neighboring colonies,” he adds.
Of the two other major bee-killers vanEngelsdorp listed, pesticides have arguably gotten the most press—especially a commonly used category called neonicotinoids. While considered safe for humans, research suggests neonicotinoids may be extremely harmful to bees and many other insects, and so have been banned in some European countries. But the amount these chemicals contribute to bee deaths and colony collapse disorder is still debated. “We don’t find levels of neonicotinoids that are indicative of widespread exposure or harm,” vanEngelsdorp says.
The third problem—poor nutrition—is likely the most confounding of the honeybee’s enemies.
“Bees need a varied diet of different pollens in order to grow into strong, healthy workers,” explains Dr. Heather Mattila, a honeybee biologist at Wellesley College. Unfortunately, a country once filled with meadows of diverse, pollen-packed wildflowers is now blanketed by crops, manicured lawns, and mown fields barren of pollen sources. “A green space can be a green desert if it doesn’t have flowering plants that are bee-friendly,” Mattila adds.
Combine a restricted diet with environmental factors like extremely cold winters and scorching summers, and stressed honeybee colonies are less able to resist the ravages of mites, pesticides, viruses and other potential causes of colony collapse disorder.
To fill nutrition gaps, beekeepers give their wares pollen supplements. Along with tactics like colony splitting, keepers can restore their bee supplies quickly during the spring and summer months. But Hunt says the cost to do this is large—and growing larger. “As long as beekeepers are willing to put more money and hard labor into it, we can come back and rebuild our colonies and numbers,” he explains. “But whether this is all sustainable is an open question.”
Mattila calls this a “Band-Aid,” not a cure. “I think we’re making the best of a tough situation,” she says. Both she and Hunt applaud companies and localities that have started letting wildflowers grow along the sides of highways or under rural power lines—places that used to be mown and sprayed with herbicide. The federal government has also taken steps to protect lands that offer honeybees (and lots of other insects) the sustenance they need. Mattila says every American can help these efforts by planting flowers and avoiding chemical treatments.
But she mentions another emerging concern when it comes to the future of America’s honeybees: The strange, abrupt deaths of many bee queens. “When I started working with bees 18 years ago, we’d replace living queens every two years,” she recalls. “Now queens die after half a summer. Nobody is really clear on why.”
The “Band-Aid” she mentioned might already be coming off.