Neonics Face Even More Scrutiny Amid Bee Health Concerns

August 8, 2016 08:48 AM
Neonics Face Even More Scrutiny Amid Bee Health Concerns

Is one of the most popular seed treatments in trouble?

By some accounts, the neonicotinoid class of insecticide seed treatments is a runaway success, planted on millions of corn and soybean acres every year to protect young plants.

Even so, its link to bee toxicity has many European countries banning neonics, with an Environmental Protection Agency (EPA) registration review in progress in the U.S. 

“A very important part of [this process] is the benefits and alternatives analysis,” says Kelly Ballard, chemical review manager, EPA. “What we mean here is the benefits of the chemical to farmers and the economy as a whole. What would be the impact if we were to remove a chemical? How would that affect farmers and the economy? What types of alternatives would be used?”

The docket is enormous; the imidacloprid review alone includes more than 100 studies and 400,000 public comments. EPA plans to publish a follow-up assessment by December 2016. For more details, see John Dillard’s column on the next page.

Regardless of the outcome of EPA’s regulatory review, neonics are taking a hit. For example, Home Depot and Lowe’s each pledged to phase out products that contain neonics.

In addition, 12 Midwestern universities recently released a publication suggesting farmers overuse neonic seed treatments in soybeans. The researchers note neonic seed treatments offer soybean seedlings a three-week window of protection after planting that manages early season pests. However, the treatments’ usefulness is primarily confined to “targeted, high-risk situations” such as:

  • Fields recently converted from CRP or grassland to soybeans.
  • Fields with manure, green cover crops or weeds.
  • Double-crop or specialty (food-grade or seed) soybean fields.

Other high-risk scenarios such as wireworms, white grubs and seedcorn maggots are uncommon where soybeans are grown. Adult bean leaf beetles cause cosmetic damage in newly emerged soybeans.

Unfortunately, these neonic seed treatments have little value controlling one of the biggest soybean pests—aphids. Neonic seed treatments are labeled for soybean aphid, but thresholds often occur weeks after the seed treatment’s window of protection ends. Natural predators such as Asian lady beetle and parasitic wasps often suppress early season infestations of soybean aphid.

Just like patients expect to know why a doctor wrote a particular prescription, farmers should expect to know why insecticidal seed treatments are recommended, says Chris DiFonzo, field crops entomologist with Michigan State University.

“I am not saying that neonic seed treatments aren’t justified—they just are not justified as often as they are used in soybeans,” she says. “I recognize it may not be easy to get seed treated with fungicide only, for example. Many dealers offer only combo products, or only guarantee seed treated with a full package of insecticide and fungicide. If growers want more choice in seed treatment in the future, the message is they have to speak up and be persistent.” 

Not the Only Culprit

Neonicotinoids are often targeted for their possible role in Colony Collapse Disorder (CCD), a scourge that’s devastating bee populations and costing beekeepers billions. It’s not the only factor at play, however. Kim Kaplan, a public affairs specialist with USDA–Agricultural Research Service, says it’s likely a combination of factors that trigger CCD.

“These factors tend to overlap and interact with one another, which complicates issues,” she says.

Additional factors include: pathogens, improper nutrition, parasitic mites, sub-lethal doses of pesticides, migratory beekeeping (which can stress the hive) and climate change.

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Spell Check

Crown Point, IN
8/11/2016 04:04 PM

  @ Pete.Did you ever hear of planter dust that’s one rout of exposer contaminated planter dust drifting in nearby fields contaminating non-target plants like dandelions that bees visit. Guttation fluid that bees collect is another problem. A more serious problem is the fact that only about 10% of the compound gets absorbed by the plant, being water soluble the rest of it ends up in the ground water to be absorbed by non-target plants and contaminating rivers and streams.

Harrell Clement
Alamo, TN
8/8/2016 02:56 PM

  I know there are many factors effecting bee populations. On may own farm I can remember as a kid, you didn't dare walk across the yard bare-foot when clover was in bloom. So many home owners now days want there yards to look like golf greens. I tried it myself for a few years. Keeping the yard that way became a year after year battle. I finally gave it up and let nature grow what ever it wanted to grow. Early this spring I pulled up to my house got out of my truck and heard this bussing noise on a holly type bush at the corner of the house. It was wild honey bees harvesting the tiny blooms. The adrenal flowed through my body because this was something I haven't seen in years. There was a lot of clover that had come back in the backyard so I just mowed around all the big patches. As the clover bloomed the bees started harvesting it. We also raise about an acre of purple hull peas each year. In the past it has always been a automatic spray at bloom. This year there was so many parasitic wasp and the bees, I choose not to spray. The peas had no worms and each day when I got off the tractor I would go to the pea patch and help my wife pick just for the enjoyment of watching the bees. I'm not a big farmer and haven't pushed out my fence rows. This helps keep my chemical drift off my neighbors and there's of me. I have areas around my shop and behind house that I just let nature grow what it wants to grow and don't mow it down until mature. They say beauty is in the eye of the beholder. For some that is wide open fields of beautiful chemical crops. For others it's beautiful chemical golf course yards. I think those things look pretty too. At 62 years old I know now that my greatest beauty is watching those bees harvest those wild plants they were meant to harvest and not forced to harvest those we make a living from. Everyone needs to leave them a little natural home. That's where they will get there strength back and also shows we care about the future.

Spencer, IA
8/9/2016 12:33 AM

  Since wide adaptation of neonicotinoid soybean treatments in NW Iowa we do not see aphids until mid to late July which is about a month later than fields that were untreated. When they first came out we observed a direct correlation on aphid counts in the treated vs untreated. In a "bad" aphid year untreated fields were sprayed in mid July and again in mid to late August. The fields with seed treatment had lower numbers and we were able to hold off spraying until late July early August which is late enough that retreatments were not warranted. Also we have observed the neonicotinoids sprayed post give 7 days more residual than any other labeled soybean insecticides that are commonly used. Whoever made the statement that neonicotinoids are of little help in aphid control is simply wrong. I would also like someone to explain to me how a properly applied neonicotinoid seed treatment on a seed that is properly planted in the soil, in a field, and on a plant, that bees do not feed on can affect them.


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