Bees in peril

Published January 22, 2006 12:01 am
Parasitic mite takes toll on hives of vital insects in Utah, across country
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The bee varroa mites are back, grown resistant to chemical pesticides and once again attacking Utah's most enduring state symbol.

The eight-legged parasites are infecting hives not only in Utah but throughout the United States and worldwide, feeding on larvae, pupae and adult bees, sometimes killing off entire colonies.

"We've had more losses in the fall and early winter than we've ever had, and there's no good solution," said beekeeper Robert Newswander of Logan, whose 5,000 colonies make him one of the state's largest honey producers.

Bees are an irreplaceable part of the food chain. They pollinate all fruit and seed crops, clover for animal forage, cotton used for oil and fiber, as well as flowers. And because most vegetables are actually fruits, bees also pollinate garden produce such as tomatoes, peppers, beans, peas, corn, squash and cucumbers. In other words, no pollination - no fruit.

In the early 1990s, when the mites first struck hives in the United States, Utah's etymologist announced that after a single infected colony had been destroyed, the state was free of the infestation. But those reports turned out to be exaggerated.

The hardy mites have repeatedly adapted to new pesticides. Beekeepers can keep infestations under control in the early stages by using natural acids, mineral oils or strips of the pesticide Apistan, which cannot be applied during honey flows.

New pesticides also are coming to market, but the compounds are not highly effective in knocking down the mite populations because applications are labor intensive and must be constantly reapplied, said Rosalind James, research leader at the USDA Bee Biology and Systematics Laboratory at Utah State University. When the pesticides are used properly, neither the bees nor the honey are contaminated.

Beekeepers can also buy Russian queen bees, which have developed some resistance because the parasites migrated west from Asia. But Russian bees are more aggressive than the European honeybees favored by Utah farmers.

"Some of our own bees also seem to have a natural ability to cleanse themselves of the mites, and hopefully that attribute will help in the future," said Robert Yack of Roosevelt, who shipped his 1,600 hives to help pollinate almond trees in California this winter.

Hobbyist Larry Knowlden, who keeps bees in his Taylorsville backyard, said beekeepers with smaller operations also are losing bees. While his colony weathers through the winter, he's fearful that commercial bees will pick up more parasites before they're shipped back to Utah in the spring.

"Our beekeepers are pretty conscious; they know what they need to do to control the mites," said state entomologist Ed Bianco. "But it's also something they've had to learn to live with."

The varroa mite, about the size of a match head, attaches itself to the host's body, while another common pest, the tracheal mite, infects bees internally. It is the bees' most well-known attribute that makes them susceptible to the parasites - their ability to live in closely packed communal nests or hives.

"That's what happens when you take wild things and bring them into close proximity," said researcher James. "You increase the chances for the spread of diseases and parasites."

Loss of habitat and infestations are some of the factors in the declining number of colonies in the Beehive State. Since 1997, colonies - which can support from 20,000 to 60,000 individual bees - have dropped from 32,000 to 23,000.

Utah honey is a $1.7 million industry annually. Even though honey yields have recently increased because of better weather conditions, the price per pound from 1994 to 2004 has jumped from 75 cents to $1.04, according to the Utah Department of Agriculture and Food.

To make up for the shortage of honeybees, Utah researchers are looking to other so-called second-string pollinators that don't produce honey, such as the Utah native blue orchard and alfalfa leafcutter bees.

The blue orchard bee, whose small size and iridescent-blue sheen can be confused with a fly, pollinates orchards. These bees also work longer hours than honeybees and in colder temperatures.

The black leafcutters, sporting bands of white hair on their abdomens, pollinate onions, carrots and alfalfa blooms. They'll also fly into enclosed gardening spaces, often shunned by honeybees.

Despite the mites, Utah beekeepers' aren't worried about the long-heralded invasion of Africanized, or so-called killer, bees that mate with their gentler cousins and produce far less honey. Africanized bees are staying away from colder climates so far, and state beekeepers make it a point to travel to areas free of the aggressive invaders.

Nationally, Utah is 24th in honey production. Top production honors go to North Dakota and South Dakota, respectively, followed by Florida, California and Montana.




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