Tribune Reporter
One day last week, Bronwyn Weaver carefully pulled apart and examined a dozen white wooden beehives near the Morton Arboretum’s prairie, checking to see if it was time to harvest honey from their combs for the last time before winter.
Weaver, the Arboretum’s new beekeeper, was also making sure the hives, each a colony of perhaps 60,000 inhabitants, were in optimal shape to protect the bees over the winter.
That’s a season that in recent years has been particularly deadly to bees in northern Illinois. Most beekeepers in this part of the state have seen the bees in 70 percent of their hives perish in the unusually harsh winters the last few years.
The winter die-off is even more lethal in this area than the still-unsolved mystery of the better-known colony collapse disorder, which hasn’t hit Illinois but in warmer climates around the world has annually been killing off 30 to 50 percent of honeybees since 2006.
The arboretum’s bee colonies are part of an experimental effort to develop hardier stocks of locally bred queen honeybees that are better adapted to northern Illinois environments.
“What’s killing our bees isn’t clear yet, but seems to be a perfect storm of problems,” Weaver said.
Among them are a host of new pesticides, fungicides and herbicides that Illinois farmers have been using in the last couple of decades. Many of them are used to fight new bee viruses and pests coming from Europe, such as varroa mites, which attach themselves to bees and feed on their blood. But pesticides used to kill varroa mites weaken bee immune systems, too, leaving them susceptible to cold weather.
“We also have had this strange weather these last few years that can impact how the hives survive,” Weaver said. “This past winter, we did not have a weeklong thaw in January, like we usually do, when temperatures can momentarily rise into the 50s.”
As winter sets in, the tens of thousands of bees in a hive form a tight ball in the hive to keep warm. After weeks of indoor living, at some point they have to fly outside for at least for a few minutes to defecate. If they can’t get outside, serious health problems ensue.
While cold weather is a problem, Illinois, which does not have a major honeybee industry, has not yet had a confirmed case of colony collapse disorder, or CCD.
In states where honeybees are crucial to pollinate major crops such as apples, almonds and cranberries, CCD has decimated commercial honeybee populations, killing off as much as 30 to 50 percent of honeybee populations in Southern, Western and Northeastern states.
“The honeybee is the world’s premier pollinator,” crucial to the world’s food supplies, said May Berenbaum, head of the University of Illinois at Urban-Champaign’s entomology department, who is active in honeybee research.
Honeybees pollinate plants that provide 35 percent of the foods humans eat. Without the bee pollination service, humans would lose a $15 billion industry.
Most Illinois farmland is used to raise two crops that don’t need bee pollination, corn and soybeans. Nonetheless, the state has thousands of beekeepers maintaining perhaps 15,000 colonies. A few are larger commercial operations, but most of them are part-time or hobby businesses.
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Illinois bees gather nectar from wild and cultivated flowers, providing distinctive flavors to honey. Local keepers often package and sell these “craft” honeys in specialty stores.
Three years ago, several Illinois beekeepers, concerned about the winter die-offs, banded together to found the Illinois Queen Initiative. They trained other keepers to raise their own queen bees. Now 130-strong, the group is importing foreign bee breeds to introduce to Illinois colonies, hoping to develop bees that are genetically superior and more disease-resistant.
The key to the group’s efforts are the queen bees that rule over each colony. Each queen propagates and presides over several generations in her one- to three-year life cycle.
Shortly after beginning her rule, the queen flies one to two miles away from the hive with a few colony males for a two- or three-day mating period, the only one in her life. When she returns to the hive, she stays inside for the rest of her life, depositing as many as 1,500 fertile eggs a day, up to 600,000 in a lifetime. That’s why the queen is the prime target of beekeepers trying to improve the genetic stock of their colonies.
Morton Arboretum, in west suburban Lisle, had maintained 20 beehives on its grounds for the last 20 years. When its beekeeper retired last winter, the arboretum invited Weaver, who maintains bees at Heritage Prairie Farm, an organic farm and market she owns in rural LaFox in Kane County, to take over.
Weaver expanded the arboretum’s bee population to 50 colonies spread over four bee yards around the property, using the bees in the Queen Initiative experiment. She also packages the honey from the arboretum, which it buys back and sells in its gift shop.
“We’re keeping very careful records on each of our hives,” Weaver said of the arboretum bees. In the 1970s, she said, a normal winter die-off would have been 10 to 15 percent of the hives, but in the last few years it has been 50 to 80 percent.
The difference next spring, she said, will be how they will replace the queens of colonies that die during the winter. In the past, Illinois beekeepers always imported new queens from the South or California, which have breeders specializing in raising queen bees.
Next spring, Weaver and other members of the Queen Initiative will use female honeybee eggs in the hives of their own colonies that survived the winter, instituting a natural process that transforms the eggs to queen bees.
Weaver will place a single fertile female egg in a special cell in the hive called a queen cup. As the egg transforms to the larval stage, nurse bees for the next nine days feed it royal jelly, a protein-rich secretion from the nurse bees. The queen-to-be then pupates, emerging in little more than a week as the new absolute monarch of the hive, ready for her mating flight.
“The idea is to have locally adapted queens to head up colonies that can survive our winters,” said Philip Raines, a large-scale bee farmer in rural Davis, near Rockford and one of the founding members of the Queen Initiative.
The expectation, he said, is that locally reared queens will pass on genes that helped her mother colony to survive tough Illinois winters when so many others perished, eventually strengthening succeeding generations until most Illinois honeybees will be locally bred and fully adapted to live here.
If beekeepers and scientists don’t solve the problems of winter die-off and CCD, he said, it will cause serious problems.
“In recent years, we lost 60 to 70 percent of our colonies, and we want to get that down to 10 or 15 percent,” Raines said. “If we don’t get better bees and we continue to see these huge die-offs, this country will end up having to import more and more food.”