Multiple causes suspected in decline of Iowa bees

SOUTH AMANA - Up to 40,000 worker bees bustle in one nightstand-sized hive at Noble Bee Honey.

That healthy buzz hasn't been the norm in recent years because of colony collapse disorder.

“We never had a problem like this when I started in the 1990s,” owner Matt Stewart said of the phenomenon, first identified in the United States' bee population in 2006. “Ones with the disease, they're leaving. They're going off to die somewhere.”

Colonies with the disorder have a live queen, but no adult honey bees or dead bees in the hive.

Colony collapse takes an annual toll. Like many other Iowa beekeepers, Stewart has been losing up to 70 percent of his bees each year. Before the disorder, about 20 percent might die over winter.

Research is under way at Iowa State University, the University of Iowa and elsewhere, but no single underlying cause has been pinpointed, said Andrew Joseph, Iowa's state apiarist, or beekeeper.

Cases of colony collapse disorder have been confirmed in Iowa for several years, he said, including one commercial beekeeper who lost more than 5,000 colonies in Eastern Iowa last year. That's likely just the tip of the iceberg.

“The reality is that it happens more without being reported to us,” Joseph said. “It is very much here. Our bees are sick. That's what it comes down to.”

UI biology professor Steve Hendrix said even as scientists work to understand colony collapse, a new term has emerged that reflects reality: unexplained overwintering losses. Hendrix is working on a study with wild bees collected from Iowa's prairie preserves, also important pollinators.

Scientists are concluding that colony collapse likely has more than one cause, Hendrix said, citing fungal diseases and new viruses among the pathogens and pests.

Those factors take a toll on the bees' health, he said, similar to a person weakened by illness who catches pneumonia and dies of that disease, rather than the initial illness.

“One other thing happens, and that's what knocks them down,” Hendrix said.

Joseph cited a fungal parasite, nosema ceranae, which gives bees dysentery, and varroa mites that pierce and leave gaping wounds in bees among factors weakening colonies. Fewer pollen sources that provide bees with proper amino acids and other nutrients also likely play a role, he said.

European studies have cited genetically modified crops as another factor, but Joseph said similar studies have not been conducted in the United States. He and others discount cellphone signals - a theory that made international headlines - as a cause.

Iowa has about 2,000 beekeepers, with a total of 30,000 to 35,000 honey bee colonies. The majority are hobbyists who keep two to seven colonies, with a dozen or so commercial beekeepers keeping thousands of colonies. Those commercial bees usually go to California for the winter, where the almond crop relies on honeybee pollination.

Joseph said beekeepers are paid about $100 per colony for pollination work - income needed to balance annual deficits to buy new bees each spring.

According to the U.S. Department of Agriculture, bee pollination is responsible for $15 billion in added crop value annually, particularly for nuts, berries, fruits and vegetables. In Iowa, honeybees generally are not needed for the state's two major crops, corn and soybeans, but Joseph estimated the value of bee-pollinated crops at about $180 million for apples and other fruits and vegetables.

Iowa also has an annual honey crop of about 2 million pounds, with a bulk price currently at $1.70 per pound.

Stewart and his wife, Patty, hope to collect 60 pounds of buckwheat honey to sell at Saturday's Downtown Farmers Market in Cedar Rapids. The $6 per pound that specialty honey brings won't compensate for all their losses, but the couple's 50 hives provide a sustainable living, while Patty Stewart works part time at the Ox Yoke Inn in Amana.

When customers ask how they can help, Stewart points to avoiding pesticide use and planting good nectar sources, such as red clover and bee balm.

Stewart said the way to really bring back the bees' health isn't likely to happen: returning to a different era of agriculture.

“Modern agriculture has really done a one-two punch on them,” Stewart said. “Honeybees aren't healthy anymore, and this is bringing them down.”

[naviga:h6 class="zemanta-related-title" style="font-size: 1em;"]Related articles

[naviga:ul class="zemanta-article-ul"]

[naviga:li class="zemanta-article-ul-li"]Beekeeping can supply you and neighbors with honey (usatoday.com)[/naviga:li]

[naviga:li class="zemanta-article-ul-li"]The Beekeeper Dilemma (freakonomics.com)[/naviga:li]

[/naviga:ul]