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June 13, 2013

Pesticides Contribute to Decline in World's Bee Population

by Kane Farabaugh

A steady decline in the overall honeybee population year to year is a growing problem worldwide. The decreasing bee population could contribute to a dramatic increase in commodity prices for goods dependent upon pollination by honeybees. Researchers continue to study the decline as beekeepers are struggling to keep their colonies, and their profits, alive.

Terrence Ingram considers himself a naturalist. He said he’s best able to commune with the natural world around him at the center of a swarm... of bees. “I love beekeeping. It’s one of God’s greatest miracles."

Since 1954, Ingram has raised tens of thousands of honeybees in managed colonies behind his house in rural Apple River, Illinois.

“We had 250 hives at one time. We sold five, six tons of honey a year,” said Ingram.

Falling honey supplies

But that amount is dwindling. "Now we’re down to about probably four tons." And that's not because the 73-year-old Ingram is slowing down, but because he says there are fewer bees producing honey, something he blames on the use of insecticides and herbicides in the farmland surrounding his property. The gradual decline in his bee population began in 1996.

“Every three weeks that summer, they were spraying with the airplane, and by the end of the year, I didn’t have any of my 250 hives left,” he said.

This phenomenon caught the attention of researchers like Purdue University Entomology Professor Christian Krupke.

“There have been similar reports from Europe in the past, and so we looked into it a little bit further from the point of view of wondering first of all what is killing these bees, and second how are these bees acquiring whatever this toxic chemical is,” said Krupke.

There are many reasons for the worldwide bee decline, not just insecticides.

But in this instance, Krupke and his colleagues focused on insecticides - known as neonicotinoids - that adhere to the seeds as they are planted in the ground, rather than from spraying above.

“The two compounds that kept coming up when we tested these dead bees were the pesticides clothianidin and thiamethoxam. Those are insecticides that are applied to corn seed. The key route for those acute bee kills that we have seen in past years and again this year is the planter exhaust. The talc that contacts seed and then is exhausted,” said Krupke.

Omitting insecticides

About 30 years ago, there were about 4 million of these kind of managed bee colonies throughout the United States. Today, there are less than 2 million, and researchers say that’s due in part to the introduction of these insecticides.

“Can we get by without neonicotinoids insecticides in these field crops? I think we can. I believe we have data that show that we can. So that’s maybe something that’s a little more promising as far as reducing the stress on the honeybee population,” said Krupke.

In December, the European Union plans to ban the use of certain insecticides researchers linked to bee deaths. But no such restrictions are planned in the United States. For Illinois beekeeper Ingram, some of the damage already done is permanent.

“We’ve got many bee keepers who have quit, just gone out of business because they can’t succeed,” he said.

But not Ingram, who said his passion for bees is just as strong as it was when he tended his first colony, more than 60 years ago.