Innovación y tecnologíaEne. 9, 2012
EE.UU: científicos estarían desarrollando abejas reinas más resistentes a enfermedades, plagas, inviernos, domesticas y más productivas
On a farm on the outskirts of Frederick, Kelly Rausch and Adam Finkelstein crack open a wooden beehive whose design dates to the 19th century. Inside, they point out a superbee they have made for the 21st century.
In two months, the carefully bred queen bee has built a large, productive colony that knows how to cluster against the cold and fill the winter larder with honey.
More important, her bees have sought out and destroyed a sneaky parasitic mite that feeds on their baby sisters. “The bees are definitely taking care of everything,” said Finkelstein from behind his veil.
The desire for a bee that will look after itself may seem pretty basic. But with as many as one-third of honeybee colonies routinely dying off each year and the rest requiring extraordinary care, the quest for a better bee has become critical.
Scientists are trying to find the cause of colony collapse disorder, the five-year-old phenomenon of worker bees suddenly disappearing. Other maladies abound and may be a factor in the disorder: new pests and diseases, the effects of pesticides and the strain of industrial-scale pollination.
Farmers rely on the insect not just for honey, but also to pollinate much of our food.
From their five bee yards in Frederick County, Rausch and Finkelstein run a business called VP Queen Bees, which supplies breeder queens to producers at up to $165 a queen. The producers, in turn, propagate daughter queens by the thousands and sell them to commercial beekeepers and backyard hobbyists for about $30 each.
The object: a queen that will pass on to her colony the traits of disease and pest resistance, gentleness, productivity and winter hardiness.
The single greatest threat is an Asian mite called the varroa. It feeds on honeybee young and adults and spreads viruses.
Commercial beekeepers have turned to heavy feeding and medication to try to keep hives strong in advance of their biggest gig of the year. In the new year, beekeepers will assemble more than a million hives — half the nation’s stock — in the almond groves of California’s San Joaquin Valley, to ensure a successful pollination of the 2012 nut crop.
One of the bright spots has been the development of a bee that battles the mite.
Marla Spivak, an entomologist at the University of Minnesota, began breeding bees to fight back nearly 20 years ago. She froze pupae and waited to see which colonies would fastidiously remove the corpses from the hive. This hygienic trait, first observed in the 1940s when young were killed by disease, was effective in breaking the life cycle of the mite. She called her queens Minnesota Hygienic.
Separately, scientists at the U. S. Department of Agriculture’s honeybee lab in Baton Rouge were studying why some of their hives had low mite levels. After about 10 years of work, they finally figured it out. The bees in those colonies were able to detect mites hiding in sealed cells and feeding on developing young. The bees uncapped the cells and dragged out the mites, along with infested brood. Hybridizers label these neatnik bees varroa sensitive hygienic (VSH).
Tom Glenn, of Glenn Apiaries in Fallbrook, Calif., has worked with the lab to produce VSH breeder queens for queen producers around the nation. After 10 years, about 25 percent of the nation’s honeybees have significant hygienic behavior in their DNA, Glenn said.
As vital as the hygienic bee is, the breeder must preserve existing desirable traits — a reluctance to sting or swarm, for example, as well as genetic diversity as a hedge against future diseases or pests.
“That’s why gains are so slow,” said Susan Cobey, a bee geneticist at the University of California and Washington State University. “I would say we are just in the infancy of bee breeding.”
Finkelstein, however, says he thinks he is close to achieving his primary aim of creating a bee that can survive with just basic husbandry. He says he hasn’t medicated his hives in 14 years.
Another challenge is that unlike with apple or cattle breeding, for example, the average bee breeder cannot control the male line. The queen mates on the wing with 2o or so drones from surrounding colonies. The most able breeders are getting around this by artificially inseminating virgin queens with the semen from known drone stock, a technique perfected by Cobey. Only a handful of hybridizers can do it. Glenn is one. Rausch is another.
Creating a superbee is one thing, getting professional beekeepers to accept it is another. For now at least, there is enormous resistance by the commercial beekeeping industry to using improved bee stock without the continued regimen of medication and supplemental feeding.
“The large commercial beekeepers are essentially farmers, and they’re risk averse,” said Robert Danka, a research entomologist at the government’s Baton Rouge lab. “This is a very dangerous parasite we’re dealing with, and a vast majority believe if you stopped treating with chemicals, their bees will die,” he said.
Pat Heitkam, a major queen producer in Orland, Calif. said he spends “in excess of $40,000” a year medicating his queens against gut disease. “I’m not sure it’s necessary,” he said, but he can’t risk selling diseased bees to his customers.
Under a new initiative, entomologists are working with queen producers in California to evaluate colonies for the strongest stock. Organizers hope that this, in turn, will lead to the selection of hardier bees and, ultimately, less reliance by beekeepers on chemical treatments. The 20 producers in the program raise about half the queen bees sold in the United States.
Near-term salvation may come from backyard hobbyists, who are more willing to risk losing an unmedicated colony.
Karla Eisen of the Prince William Regional Beekeepers Association tracked the fortunes of more than 40 hives over two years and found the survival rate of locally sourced hives and queens — most of them from Rausch and Finkelstein — significantly outperformed traditionally sourced queens and bee packages from the South.
After two winters, 74 percent of the local colonies were still alive compared with 40 percent of the Southern bees.
“They call it the James Bond approach,” Spivak said. “Live and let die. You keep colonies without any medications. In theory it sounds good, except you reduce the gene pool” by losing bees that might have other valuable breeding traits.
Everyone agrees that a bee that could survive pests without the stresses of chemicals “would make beekeeping a lot easier,” said Reed M. Johnson, an entomologist at Ohio State University. In the nightmarish maze that the honeybee has found herself, breeding, he said, “is really our way out.”