Bees affect your daily life a lot more than you might think. Aside from giving us honey and wax, they pollinate plants that provide a quarter of the food eaten by Americans, accounting for more than $15 billion in increased crop value per year, according to the U.S. Department of Agriculture.
But bees around the world have been dying in droves for the past several years, and scientists are still struggling to understand why. The problem seemed to be getting better last year, when U.S. beekeepers reported losing only 23 percent of their colonies over the 2013-2014 winter. That's still a lot of bees, but it was at least below the average winter losses of nearly 30 percent from 2005 to 2013.
Now, however, things seem to be getting worse again. U.S. beekeepers saw annual losses of 42.1 percent between April 2014 and April 2015, according to a new federal survey. Winter is normally the hardest time of year for honeybees, but the 2014-2015 winter actually had fewer colony losses (23.1 percent) than 2013-2014 (23.7 percent). The problem, researchers say, is that a huge number of honeybees died last summer, with beekeepers reporting summer losses of 27.4 percent in 2014 versus 19.8 percent in 2013. In fact, summer is now deadlier than winter for many commercial beehives.
"We traditionally thought of winter losses as a more important indicator of health, because surviving the cold winter months is a crucial test for any bee colony," survey co-author and University of Maryland entomologist Dennis vanEngelsdorp says in a statement. "But we now know that summer loss rates are significant too. This is especially so for commercial beekeepers, who are now losing more colonies in the summertime compared to the winter. Years ago, this was unheard of."
The survey focuses on commercially managed honeybees, which are often trucked long distances to pollinate single-crop farms in the growing season. The stress from this pollination workload could be responsible for some of the reported summer losses, but the study also points to a broader problem for pollinators — and the ecosystems they help support. As co-author and University of Georgia entomologist Keith Delaplane tells the Associated Press, honeybees are like canaries in a coal mine.
"What we're seeing with this bee problem is just a loud signal that there's some bad things happening with our agro-ecosystems," Delaplane says. "We just happen to notice it with the honeybee because they are so easy to count."
Starting in October 2006, honeybees in the U.S. and elsewhere began mysteriously disappearing from their hives, a condition that has become known as colony collapse disorder (CCD). The causes of CCD are still hazy nearly a decade later, but research suggests the disease has a variety of triggers, such as habitat loss, invasive varroa mites and pesticides, including a class of insecticides known as neonicotinoids. Once a colony loses enough adult bees, it can suffer a downward spiral caused by young bees trying to pick up the slack before they're ready, essentially growing up too fast.
These problems aren't unique to managed bees, either. Wild bumblebees are also in decline, possibly even catching diseases from domesticated bees, although lack of visibility means their woes tend to get less human attention. And while much of the focus has been on neonicotinoids, other pesticides pose sub-lethal threats that still imperil bees. A 2014 study found pyrethroids can stunt the growth of young bumblebees, resulting in smaller workers that may be less effective foragers.
While we may not know exactly what's harming bees, we do know what can help them. Ordinary people are often powerless to stop wildlife declines — white-nose syndrome in bats, for example — but there are things almost anyone can do to benefit bees. Not using insecticides in your garden is a big one, as is buying organic produce to support farmers who don't use pesticides on their crops. You can also plant a mix of flowers to feed local bees, preferably native species that bloom at different times of year. Clover is a good option, as are sage, echinacea and bee balm, but check to see what's native where you live.
Beyond feeding bees, you can also create habitat for them in your yard. Setting out bee blocks creates a local refuge for wood-nesting bees, and burrowing bees will appreciate a few mounds of loose dirt, especially if it's near a water source. Check out this guide by MNN's Chris Baskind for more ideas.
A block of wood or a backyard clover patch probably won't make much difference to colonies of overstressed commercial honeybees, of course, but it might help your local population of native pollinators. And if we've learned anything from these incredibly industrious insects, it's that a society can only work big miracles when each member stays busy scrapping together small ones.
Related on MNN:
- How to garden for bumblebees
- Help bees with a device on your keys
- Vanishing bumblebee defies extinction