ith a “waggle-dance” in the hive, honeybees signal to their work mates how to find the flower patch out there that will provide their food.
But who can waggle-dance clearly, or forage for nectar, when drunk on powerful pesticides?
“I think ‘being drunk’ is a good analogy because they are just not as productive,” said Reed M. Johnson, an entomology professor from Ohio State University and a guest of honor – second only to the honeybees themselves – at a special event Saturday at the Buffalo and Erie County Botanical Gardens.
For the second year in a row, the Botanical Gardens paid tribute to the sophisticated air force that is crucial to the dinner table. Pollination by honeybees sustains crops of apples, cherries, watermelons, raspberries, onions and especially almonds. The U.S. Department of Agriculture values the more than 90 crops that bees pollinate at $15 billion a year.
Honeybees have been dying off in large numbers. The commercial beekeepers who make their colonies available to farmers noticed a decade ago that bees were abandoning their hives. The phenomenon came to be known as “colony collapse disorder.’’ Suspicion landed on a class of insecticides called neonicotinoids.
Chemically similar to nicotine, neonicotinoids are suspected in bee die-offs in Germany and France, as well. A Harvard University study in 2012 linked bee deaths to one specific and widely used neonicotinoid. A study in the United Kingdom drew similar findings.
Johnson, who is wiry, youthful and loves talking about honeybees, says more scientific study is needed to conclusively link neonicotinoids to colony collapse disorder. But he agrees insecticides are among the threats to bees.
“If they get just a little dose, does that mess up their ability to communicate and to maintain this complex society?” he said. “There’s all sorts of intricate things that are going on in there, and a little bit of insecticide may throw things off.’’
Honeybees face other dangers. Herbicides, for example, suppress an important source of nutrition – flowering weeds. Then there’s the Varroa mite.
Imagine if humans had a rat clinging to their shoulder blades sucking out blood. That’s what Varroa mites are to honeybees, said Gary Piatek, who keeps bees for honey at his Grace Apiaries in Arcade and was at Saturday’s event, which was attended by about 75 people.
“Not only do they suck their blood, they also vector viruses into the hive,” Piatek said of the parasitic relationship between Varroa mites and honeybees. “They weaken the immune system of the whole hive, so consequently the hive is more susceptible to invading viruses. Bees do not have a very strong immune system on their own.’’
The pesticide industry has lashed back at efforts to blame its products for colony collapse disorder: “There is a difference between natural bee loss and the condition referred to as ‘colony collapse disorder,’ the industry group CropLife America says on its website. “CCD is a clearly defined syndrome with specific symptoms, and scientists cannot attribute these losses to any singular cause.’’
Meanwhile, everyone involved in the discussion about honeybees agrees they are invaluable to agriculture and that the world must maintain adequate supplies to pollinate crops. Some commentators have voiced fears that honeybees are the canary in the coal mine, and that other pollinators, such as butterflies, may suffer as well.
Piatek lost about half of his bees this winter, not to Varroa mites or pesticides but to the brutal cold. In milder winters, bees can survive with minimal losses – a testament to their communal nature.
The bees, Piatek said, lock themselves into a tight cluster around the queen in an effort to keep their hive at 70 degrees. As temperatures drop, the cluster tightens. But the bees at the outer reaches are most susceptible to the cold and most likely to die off.
In winter, bees can live for months, because they are not out working from sunup to sundown. In summer, bees survive for around four weeks – until their wings give out. They literally work themselves to death.
The queen’s role is to lay the eggs and keep the colony populated. She mates in flight with the males, who make up just about 5 percent of a colony and have little other role. While the males, or drones, are allowed a mostly sedentary, couch-potato lifestyle, they die after successfully mating once.
The worker bees are females but with undeveloped female parts, Piatek said. The youngest of them clean the hive. At about two weeks they will venture out. The older workers also guard the entrance to the hive.
A queen bee can live up to four years, Piatek said. As she weakens, the other bees sense this and will kill her. Meanwhile, new cells have been created in the hive for a lineup of would-be queens. The first to hatch and sip the special jelly that allows her female parts to develop will kill the eggs in the other queen cells, Piatek said. She then establishes herself as the hive’s egg-laying machine.
Karl von Frisch, an Austrian ethologist who died in 1982, discovered that a bee will dance to provide the location of a patch of flowers. A round dance indicates a closer food source, a waggle dance indicates one more distant. The other bees crowd around to pick up the message.
“They can communicate the distance to a patch of flowers and the direction. And they can kind of rate the source by how vigorously they will do this communication,’’ said Johnson, the associate professor from Ohio State.
“I just think bees are fascinating creatures,” he said.