Farming is in the family genes. Marc Arnusch is so sure about it he already has the future mapped out for his 2-year-old granddaughter Charlotte.
“She’s gonna be the fifth generation of our family to farm this farm,” Arnusch said, as the toddler snacked on grapes in the kitchen.
“ You can just feel that she’s very much in tune with the land, with our lifestyle.”
Arnusch is the third generation to own and work this land. His farm has about 3,000 acres in Keenesburg, northeast of Denver.
He grows a mix of grains — wheat, barley and corn. A good portion of his business comes from growing and selling seed grain, and his barn is full of equipment to process it.
One specialized machine coats each seed with a thin layer of chemicals, including a particular type of insecticide called neonicotinoids, or neonics. They target pests like wireworm that can destroy the roots of corn seedlings underground.
Inside Arnusch’s barn, seeds and chemicals go into a spinning metal atomizer at the top of the machine.
“That atomizer turns it into a vapor or a mist,” he explained. “And it coats the seed.”
Arnusch described that technology as the greatest breakthrough of his farming career — the best and safest way to protect his crops. Earlier generations of pesticides that were much more dangerous for workers to handle would be sprayed over entire fields. Neonicotinoids, which came on the market over the last couple of decades, were designed to be safer. The seed coating application lets him get extremely precise about how and where he uses them.
“ It’s the most precise thing we do in agriculture,” Arnusch said.
“ We’ve taken these doses from covering the entire footprint of an acre to just where the seed is at. When I was a kid, I can remember my dad talking about using a lot of pesticides in gallons per acre. Today we talk about using insecticides in fractional amounts of ounces per acre.”
Environmental groups and researchers sound the alarm
But experts estimate neonics are used on millions of cropland acres in Colorado. And because they’ve become so ubiquitous in farming, all those fractions of an ounce can add up when it comes to ecological impacts.
“Neonics are among the most devastating insecticides since DDT,” said Allison Johnson, a lawyer with the Natural Resources Defense Council. “They’re extremely effective at killing insects, which is why a farmer might like to use them. But the impacts are not limited to insects.”
Neonics are safer than many other pesticides in the sense that they are less lethal to mammals, but that doesn’t make them safe. A growing body of research points to developmental, neurological and reproductive problems in animals and people as the chemicals move up the food chain.
One reason they can do that is because they’re highly water soluble. That’s also part of what makes them so effective as crop protection, according to University of Wisconsin-Madison agronomist Shawn Conley.
“You put it on a seed, it gets dispersed, it moves up into the plant so when insects feed on it, it’s where it’s supposed to be,” Conley said. “But that water solubility is also one of the bad things because it makes it readily available to move off target, either leaching into the groundwater (or) moving into stream banks.”
Neonicotinoids have been found in alarmingly high levels in aquatic ecosystems and wild vegetation. Scientists have also linked them to mass pollinator die-offs.
“So if you have bees passing by butterflies who are trying to feed on these plants, they’re feeding on poison,” Johnson said.
Cory Kreft is a Rocky Ford-based commercial beekeeper who has experienced those die-offs up close. He’s reported losing up to 85% of his hives in any given year.
“We have tested pollen coming into our hives, and it’s just loaded with neonicotinoids,” Kreft said. “The pollen that comes in, the bees use that to feed the next generation of larvae. It’s an extreme amount of toxicity.”
Legislative response at the state Capitol
In response to the science, state lawmakers are now considering a proposal that would severely restrict the use of neonicotinoid insecticides.
Democratic Sen. Katie Wallace, who represents parts of Broomfield and Weld counties, is the bill’s main sponsor.
“ Pesticides are probably the issue that I hear about most from my district,” Wallace said. “Both from farmers (and) from people concerned for pollinators and for our environment.”
SB26-065 wouldn’t ban neonics outright. But it would require farmers to have a third-party expert sign off in order to use them.
“ Think of it as going from over-the-counter to prescription model for an extremely toxic class of chemicals,” Johnson said.
The next step is a first committee hearing for the bill scheduled for next week. If it ultimately passes, the law would go into effect in 2029. That timeline would coincide with similar laws recently passed in New York and Vermont. Several other states are considering their own neonicotinoid restrictions this year.
Advocates for the proposal say too many farmers overuse neonicotinoids. And science backs them up.
“There’s not a lot of insect pests (north of the Mason Dixon Line) where we need a neonicotinoid,” Conley said. “ (The pests are) very localized. But you’re throwing a pesticide out into the environment in a broad swath when it’s only isolated acres.”
Studies show they provide little to no economic benefit to farmers, because any modest value gained from a yield boost is offset by the cost of the chemicals.
“ A lot of the studies we’ve done, it’s break even at best,” Conley said.
So why are they so ubiquitous? Conley said the major seed companies sell neonic treated products as the default. It’s a profitable value add-on they can market as safe to handle and relatively cheap insurance for crops.
Unless farmers actively opt out, they often end up using neonic coated seeds whether they have a pest problem or not.
“I don’t like to see something just ubiquitously thrown into the environment and treated as an insurance policy,” Conley said. “I don’t think that is the proper use of a pesticide.”
Farmers push back
But many in Colorado’s agricultural industry disagree with the proposed restrictions and characterize the bill as condescending.
“We feel like this is an attack on our most effective and efficient and affordable practices, and we’re quite frustrated with the policy,” said Brandon Melnikoff with the Colorado Farm Bureau. “ Our producers are already facing a struggling farm economy. It would be hard for them to adjust both financially and in management.”
Melnikoff questioned why industry leaders were not more involved in drafting the bill.
“ We were not invited to the table,” he said. “And you know, there’s that saying that if you’re not at the table, you’re on the menu.”
Arnusch also bristled at the idea that he and his fellow farmers would be thoughtless about using toxic chemicals on their own land.
“ We use neonics within our operation when they’re warranted, and that’s certainly not every year,” he said. “ These things are investments in growing crop. This farm only chooses to use those investments when they make the most sense.”
“ We are passing our soils to our next generation,” Arnusch said. “Why would we do anything to damage them?”
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