Colorado farmers plant tens of millions of corn seeds every year, nearly every one of them covered in a thin layer of insecticide.

The neonicotinoids used in the coatings protect the seed from pests in the soil and, as the crop matures, the chemical is absorbed into the plant’s tissue, where it continues to paralyze and kill insects that chomp on the crop.

Farmers say the insecticide is necessary, but growing concerns about its impact on crucial pollinator species and the wider environment are prompting a push in Colorado for more regulation of the widely used class of chemicals. Environmental advocates plan to seek a bill in the state legislature in 2026 that would limit their use in hopes of protecting pollinators and water quality.

While a draft bill has not yet been made public, the environmental groups working on it said the legislation would ban the use of neonicotinoids without prior approval by inspectors overseen by the Colorado Department of Agriculture.