Midwestern beehives nearly barren
Whether you're sitting in your backyard or watching a local baseball game, there are not nearly as many bees buzzing around Ohio as there used to be. To people like Ohio State University apiculture specialist Jim Tew, it's no day in the park. And to commercial beekeepers and producers who count on bees to pollinate their crops, it can mean serious economic losses.
Many are looking to Tew and his colleagues for answers as to where the bees have gone. Despite a number of possible theories, Tew says explaining the die-off, now known globally as colony collapse disorder (CCD), isn't an exact science.
"The bees are simply gone," he says.
In the last 25 years, nearly half of North America's honeybee colonies have vanished, leaving many in the industry looking for answers. In the absence of an obvious cause, Tew points to three potential hypotheses:
- A "strong supposition" is that something is stressing the hives, particularly in the case of migratory beekeepers that transport their hives great distances to aid in pollination. These situations open the door for a number of traditional pathogens to infiltrate the hives and keep adults from returning to the colonies after foraging flights.
- The second possible perpetrator could be good old-fashioned in-breeding.
"We raise significant numbers of queens (in the thousands) that populate our hives every year. There's a question of maybe these queens are too closely related and our genetic pool is not what it should be," says Tew, who is with the Honey Bee Lab at the Ohio Agricultural Research and Development Center.
- Third is the presence of external parasites, such as Varroa mites, which keep deformed or weakened bees from emerging from their developmental stage.
None of the three possibilities are fully understood, Tew says.
"It's just about as muddy as it can be," he says. "There's just so much that could possibly be hampering the bees, to point our finger straight to it is difficult."
But the issues facing bees in the state are a little more direct than the phenomenon once known vaguely as "disappearing disease." While humans may be slightly irritated by unpredictable weather, bees can be devastated by the erratic temperatures experienced over the past three years.
Not only are colonies forced to accommodate the cold snap by dipping into their honey stores, but once the temperatures rise and bees commit to raising offspring, they die off as soon as temperatures plummet.
"We hoped for a mild spring (in Ohio) and it simply wasn't," Tew says. "A significant number of bees died and it was nothing mysterious -- nothing controversial. They just died of starvation due to poor spring honey-producing seasons."
As far back as 1969, Ohio State examined nutrition, mites, and pathogens and their potential roles in CCD, but before most of the studies could materialize, Tew said, outbreaks would spontaneously resolve themselves. Now, erratic instances of the syndrome have turned into a full-blown crisis, which has turned the microscope back on basic research.