Many factors in high bee colony losses

Pests, pathogens and pesticides are a lethal combination that can lead to high honey bee colony loss, according to a leading beekeeper.

Three or four main factors striking on top of each other is what makes the job of a beekeeper so challenging, Eric Wenger, director of procurement for Kansas-based Barkman Honey, said. But, he said, beekeepers are managing to keep up colony numbers despite increases in losses.

Mysterious colony collapses that emerged around 2006 and continued for some years have brought headlines to the industry, but they are particular events, not symptomatic of the day-to-day, and year-and-year, issues beekeepers face, Wenger told Crop Protection News.

“Beekeepers are facing a lot of challenges; they are losing a lot of their colonies and there are serious issues,” Wenger said.

A particular family of pesticides called neonicotinoids has been blamed for honey bee losses in recent years, including colony collapses, while others identify the relative newcomer to America, the varroa mite, as the biggest culprit.

Wenger is more nuanced in his thinking, blaming the combination of pests, viruses and pesticides, including those used by the beekeeper themselves.

“There are those three or four main factors often discussed, pests and pathogens, a whole host of viruses, the varola mite, agricultural chemicals combined with the varola mite,” Wenger said. “All these strike on top of each other, that leads to high colony loss.

Wenger added, “It’s a mix of different things that might be prevalent. If (it's) only one problem, the beekeepers can handle (that); otherwise it multiplies by a factor of 10.

Figures from the U.S. Department of Agriculture show an increase since the colony collapse disorder appeared on the radar in 2006. That year, there were 2.4 million colonies, compared to 2.7 million in 2014.

This is despite a reported 30 to 40 percent winter death rate, including 45 percent in 2013, well above the historic rate of approximately 15 percent. Researchers at the USDA and elsewhere said the reason the numbers are keeping steady is that beekeepers are working harder, and smarter.

While some studies have blamed neonicotinoids for the increased rate in bee deaths, there is an growing body of work that argues the varroa mite, which likely migrated to the United States in the 1980s, is the key culprit.

The U.S. Environmental Protection Agency announced a preliminary pollinator risk assessment for the neonicotinoid insecticide, imidacloprid, in January. It concluded there was a threat to some pollinators.

The EPA’s assessment, prepared in collaboration with California’s Department of Pesticide Regulation, stated that imidacloprid potentially poses a risk to hives when the pesticide comes in contact with certain crops that attract pollinators

 

Organizations in this story

Barkman Honey 120 Santa Fe Street Hillsboro, KS 67063

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