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Bees need environmental help

By Staff | Jan 30, 2015

DR. CHRISSY MOGREN, A U.S. Department of Agriculture research entomologist, talks at Dordt College about the risks posed to honey bees and other beneficial insects by neonicotinoids, a class of chemicals used in agriculture.

SIOUX CENTER – Northwest Iowa beekeepers are already planning for the warm spring days that will bring their hives back to life.

More than 60 apiarists turned out at Dordt College Jan. 15 to add to their knowledge of beekeeping, the good that bees do by pollinating important plants and the threats they face from a group of pesticides called neonicotinoids.

Even with the deadly threat of some ag chemicals, the relatively little that pollinating bees can accomplish at the edges of thousands of acres of monocultured corn and soybeans makes an important environmental contribution, according to Dr. Chrissy Mogren, the keynote speaker.

Mogren is a post-doctoral research entomologist with the U. S. Department of Agriculture’s Agricultural Research Service, working out of Brookings, South Dakota.

Mogren used detailed maps of insecticide use that visually obliterated Iowa and much of the “breadbasket” Midwest where registered compounds such as Imidacloprid, Clothianidin and other chemicals are used on crops.

According to data presented by Mogren, the U.S. Environmental Protection Agency relies on the environmental safety data generated by the ag chemical industry.

She showed how cropland can lose 90 to 98 percent of an insecticide in “planter dust” and how one pesticide dose in a single corn seed can contain several times the lethal dose for one bee.

Mogren presented a graphic showing reasons to use insecticides on crops – easy to use, targeted early season pests, killed sucking pests and were less toxic to mammals.

With their use now prophylactic, Mogren said, chemicals cost farmers money, kill beneficial insects and may increase pest resistance.

New evidence, she said, suggests some of the newer chemicals may not be as safe as those they replace.

Dr. Duane Bajema, a Dordt College professor of agriculture, teaches a beekeeping course.

He said evidence about the impact of “neonics” on honey bees and other pollinators – in which it causes neurons to fire rapidly and result in the inability to orient – conflicts with other evidence.

“Nevertheless,” he said, “some European countries have banned neonics, and Canadian beekeepers are calling for a ban.”

Bajema and Mogren encouraged bee-friendly landscapes containing flowering cover crops and conservation strips to help retain soil. They noted that North America is home to 4,000 native species of bees, 70 percent of which are ground nesters.

The two speakers asked farmers to consider no-till and cover cropping, adding one field per year; to incorporate more flowers into the landscape; to treat cropland only with what chemicals are needed and only when they are needed, and, to plant less expensive, neonic-free seed.

Mogren acknowledged that the Northwest Iowa climate is often too cold after harvest – or warm enough for too short a time – for a cover crop to germinate.

“So broadcast it aerially before harvest,” she said. “Or you could plant it while the corn is young. The corn roots will be down (and so the cover crop would not compete with the crop). You could graze cattle on it after harvest.”

And, for a bee-friendly landscape, Mogren suggested planting buckwheat, mustard, Placella, safflower, sunflower or black-eyed Susan.

She suggested mixing early, middle and late-growing cover plants.

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