Colorado Can Join Leading States by Curbing Second “Silent Spring” Pesticide Pollution

Among the most potent insecticides ever created and perhaps the most widely deployed insecticides in U.S. history, neonics have made U.S. agriculture an estimated 48 times more harmful to insect life. Their largest use, by far, is crop seed coatings that make whole plants—including nectar, pollen, and fruit—toxic to insects. Typically, only 2–5 percent of the chemicals are absorbed by the plant, leaving the other 95 percent in the soil, where they are easily carried long distances by rain or irrigation water to contaminate new soil, water, and plants. Neonics persist in the soil for many years, and the continued buildup from repeated use makes them pervasive contaminants, polluting Colorado water, soil, and plants, as well as Coloradans themselves.

Neonics are nicotine-mimicking neurotoxins that interfere with nerve receptors located in our brain and central nervous system. Monitoring by the Centers for Disease Control and Prevention has detected neonics in about half the U.S. population; more recent testing of pregnant women across the country found the pesticides in more than 95 percent of participants, with levels rising over the four-year study. Neonics pass easily from mother to fetus, and studies link neonic exposures in the womb to birth defects of the heart and brain, as well as reduced cognitive abilities. Increased rates of birth abnormalities and death have been documented in deer. Chronic exposures in adults are also linked to a host of neurological and reproductive system harms, including lower testosterone, semen quality, sperm count.  

Overwhelming evidence connects neonic pollution to mass losses of bees and other critical pollinating species (e.g., here, here, and here). These losses have lowered yields of “pollinator limited” crops nationwide, with research showing that global production of fruits, vegetables, and nuts is down because of a lack of pollinators. In Colorado, beekeepers lost more than 42 percent of their colonies last year, and continued pollinator losses threaten more than $300 million in pollinator-dependent crops. Even self-pollinating plants, like Pueblo green chiles, depend on Colorado’s native bees to thrive. Just one neonic-coated corn seed has enough active ingredient to kill a quarter million bees. 

Neonic-coated seeds are the default option for major field crops like corn and a profit center for large seed and chemical companies. Yet extensive research across North America shows that neonic grain and oil crop seed treatments typically provide no economic benefit to farmers. Rarely do these coatings provide yield benefits, and even then, the benefit rarely equals the additional cost of the coatings (Cramer and Hamby 2025, Pecenka et al. 2021, Labrie et al. 2020, Dubey et al. 2020, Alford and Krupke 2017). 

Because the coatings’ small efficacy window targets only early-season pests that seldom cause economic damage, they also fail to replace the need for pesticide treatments for major crop pests. Unnecessary neonic seed treatments can also harm farm output by killing pollinators, beneficial predators of crop pests, earthworms and other decomposers and by undermining soil health. Widespread, wasteful neonic use as seed coatings also encourages pest resistance (similar to the overuse of antibiotics), making them less effective for other crop applications.tout their benefits. Yet extensive research across North America shows that neonic grain and oil crop seed treatments typically provide no economic benefit to farmers. Rarely do these coatings provide yield benefits, and even then, the benefit rarely equals the additional cost of the coatings (Cramer and Hamby 2025, Pecenka et al. 2021, Labrie et al. 2020, Dubey et al. 2020, Alford and Krupke 2017). 

Because the coatings’ small efficacy window targets only early-season pests that seldom cause economic damage, they also fail to replace the need for pesticide treatments for major crop pests. Unnecessary neonic seed treatments can also harm farm output by killing pollinators, beneficial predators of crop pests, earthworms and other decomposers and by undermining soil health. Widespread, wasteful neonic use as seed coatings also encourages pest resistance (similar to the overuse of antibiotics), making them less effective for other crop applications. 

Neonics contaminate Colorado water at levels that are “likely causing significant and widespread damage to aquatic ecosystems and an increase in human exposure from groundwater.” Widespread neonic contamination eradicates invertebrates that other species depend upon for food, with research linking neonics to mass losses of birds and the collapse of fisheries. Neonics can also directly harm animals; one neonic-treated seed has enough active ingredient to kill a songbird, and research directly links neonic exposure to lowered bird survival and birth defects in white-tailed deer. The U.S. Environmental Protection Agency has found that current neonic use patterns are likely driving an astonishing 200-plus species toward extinction.

SB26-065 would reduce Coloradoans’ exposure to neonic pollution by adopting a “prescription” model. Neonic seed coatings could still be used but only when they’re the right solution for a verified pest problem. Successful implementation of this model in Quebec near elimination of neonic seed coatings for oil and grain crops—without crop loss or switching to more harmful alternatives. New York and Vermont will be implementing similar programs in 2029, and there are similar bills in at least half a dozen other states, pushing markets to offer safer, less expensive seed options for farmers.