Fighting the mite: may the best bee win.

Fighting the mite: May the best bee win

In a few weeks, entomologists will transport a special strain of honeybees from the marshy island of Grand Terre, off the coast of Louisiana, to selected sites in the southern part of the state. Scientists and beekeepers hope the transfer will mark the beginning of the end for a mite infestation that has swept through much of the United States since 1984, leaving millions of honeybees gasping for breath.

The tracheal mite, Acarapis woodi, makes its home in the breathing tubes of adult honeybees. By restricting oxygen intake, it robs the bee of crucial energy needed for flight, reducing the insect's lifespan by one-third. "It's like an adult [human] with emphysema," says geneticist Thomas E. Rinderer of the Agricultural Research Service (ARS) in Baton Rouge, La. The infection shortens by about two-thirds the time available for summertime bees to pollinate crops and produce honey, he adds.

Long established in Europe, the tracheal mite today poses a serious threat to U.S. hives. Chemical efforts to destroy it have met with limited success, Rinderer says. Menthol, a traditional remedy for human sore throats, can clear the mites from bee breathing tubes, but has proved most effective only in autumn, he notes. Winter temperatures prevent menthol crystals from vaporizing, leaving the mites unchecked; spring treatment may cause the menthol to mix with honey; and summer heat elicits such rapid vaporization that bees temporarily flee the irritant, abandoning their hives and broods. "It's a very chancy treatment," Rinderer says.

He and his colleagues have now turned to what they hope will become a mightier weapon: breeding. Last July, an ARS researcher brought back 15 queen honeybees, individually packaged in tiny cages, from Buckfastleigh, England. The strain has been painstakingly bred for resistance to tracheal mites by a 92-year-old monk named Brother Adam, who has practiced beekeeping for 76 years.

Now quarantined on Grand Terre, the queens and their progeny--known as the Buckfast strain -- should receive state certification of good health on Jan. 14, allowing transport to the mainland late this month for large-scale propagation, Rinderer says. This spring, he plans to send Buckfast bees to researchers in areas where the tracheal mite has taken a significant toll. Over the next three years, scientists will compare the Buckfast bees' resistance with that of three other bees--a Yugoslavian strain resistant to a mite that attacks bee larvae, a hardy commercial bee not bred for mite resistance, and a native Louisiana strain that will serve as a control. The strain showing the greatest resistance will then be bred with native honeybees throughout the nation in an effort to conquer the parasite once and for all.